Monday: Review Chapter 1 Test, finish worksheets from Friday, begin Chapter 2 vocabulary HOMEWORK: What are the steps of the scientific method? (list them) Use the scientific method today, and write down what you did for each step. 
 
Tuesday: Characteristics of cells- living things notes(available on weblog), continue chapter 2 vocabulary HOMEWORK: Study notes and vocabulary 
 
Wednesday: Cells Pre-test, Living things Worksheet. HOMEWORK: Finish worksheet if not completed in class.  
 
Thursday: Microscopes lesson, vocabulary review. HOMEWORK: Study- ch.2 vocabulary quiz tomorrow 
 
Friday: Vocabulary quiz- chapter 2 

Posted by: Team 7-2 Science

ELT: Vocabulary for chapter 1 is due during ELT this week.  
Monday: Finish Scientific Method notes. Identifying variables.  
Homework: spongebob safety and scientific method worksheet.  
 
Tuesday: Identifying controls worksheet. Chapter 1 Study Guide. 
Homework: finish study guide and have study guide signed by parent 
 
Wednesday: LAB DAY!  
Homwork: study notes 
 
Thursday: Review game 
Homework:use each vocabulary word in a sentence 
 
Friday: Chapter 1 Test 

Posted by: Team 7-2 Science

1. science 
2. observing 
3. quantitative observation 
4. qualitative observation 
5. inferring 
6. predicting 
7. classifying 
8. making models 
9. life science 
10. scientific inquiry 
11. hypothesis 
12. variable 
13. controlled experiment 
14. manipulated variable 
15. responding variable 
16. operational definition 
17. data 
18. communicating 
19. technology 

Posted by: Team 7-2 Science

Monday: Welcome! Paperwork and syllabus discussion 
Tuesday: 3 min quiz- following directions, outlining and notes over safety in the lab 
Wednesday: Lab safety poster, what no to do lab 
Thursday: finish lab safety poster, scientific method notes 
Friday: Finish notes and Scientific Method and lab safety worksheet 

Posted by: Team 7-2 Science

Text Book: 
Georgia Life Science, Pearson- Prentice Hall 
 
Supplies needed: 
1. Loose-leaf paper 
2. #2 pencils 
3. 3-ring notebook specifically for Science 
 
** pens will be allowed with the condition that there are to be absolutely no scribbles, etc. to correct mistakes. Only neat and proper work will be accepted. Students who turn in sloppy work in pen will be asked to re-do the work in a neat and orderly manner. I advise that students use a pencil the first time to keep from having to re-do assignments.  
 
AGENDA 
Always bring your agenda to class. Record the daily information and homework in your agenda. No bathroom passes during class except during extreme emergencies, and YOU MUST have an Agenda pass for a visit to the restroom. 
 
Goals: (taken directly from the GPS website) 
Seventh grade students keep records of their observations and use those records to analyze the data they collect. They observe and use observations to explain diversity of living organisms and how the organisms are classified. They use different models to represent systems such as cells, tissues, and organs. They use what they know about ecosystems to explain the cycling of matter and energy. The students use the concepts of natural selection and fossil evidence in explanations. Seventh graders write instructions, describe observations, and show information in graphical form. When analyzing the data they collect, seventh graders can recognize relationships in simple charts and graphs and find more than one way to interpret their findings. The students replicate investigations and compare results to find similarities and differences. The middle school life science course is designed to give students the necessary skills for a smooth transition from elementary life science standards to high school biology standards. The purpose is to give all students an overview of common strands in life science including, but not limited to, diversity of living organisms, structure and function of cells, heredity, ecosystems, and biological evolution.  
 
Course Outline: 
A. Structure and Function of Cells 
B. Organization of Life 
C. Heredity- Genetics 
D. Evidence of Evolution 
E. Interdependence of Life: Ecology 
F. Energy Flow & Nutrient of Cycling 
G. Scientific Process Skills 
 
Labs: 
During the year some of the labs in class involve food. If your child has a food allergy please make me aware so I can substitute ingredients if possible. Also, I may ask for volunteers to bring things in for lab. Please do not feel that you have to send these items, but anything that you can send is greatly appreciated.  
 
Projects: 
Throughout the year we will work on various projects. Some will be done in class, and some will be worked on outside of class. All projects count as a major assignment grade. Most projects will be done with partners or in groups. 
 
Grading: 
Daily Science Trivia 1x 
Classwork 1x 
Homework 1x 
Quizes 1x 
Projects 2x-3x 
Tests 2x 
 
Weblogs and Powerschool: 
Your student’s grade will be updated weekly (Tuesday by the latest) and available on Powerschool. Parents can keep up with your child’s assignments and grades. Teachers post assignment information on their weblogs, and students should be writing it in their agendas. Grades can be checked on Powerschool and are updated every Tuesday. Stop by the office to get your login information. Both of these tools can be accessed on the LMS website: www.walkerschools.org/lms 
 
Homework: 
Homework will be assigned on a regular basis. Students are expected to complete these assignments. Homework will include reading notes, written work, projects, printing out materials from Mrs. Semtner’s weblog, and other work related to science. 
 
**Assignments are due on the day set by the teacher. NO LATE WORK WILL BE ACCEPTED! 
 
Class Rules: 
1. Do your best 
2. Be prepared 
3. Be honest 
4. Be respectful 
5. Always learn 
 
Consequences: 
1. Warning 
2. Loss of stamps 
3. Parent Contact and Silent Lunch 
4. Office Referral 
5. Teacher discretion  
 
Procedures: 
Beginning Class 
1. Walk quietly into class with all your materials on time. 
2. Place your books on your desk appropriately. 
3. Read the board for essential information and write down and answer daily  
science trivia, record homework into your agenda, prepare for daily  
lesson. 
4. Look over and do today’s assignment. 
 
Ending Class 
1. If you complete all of your class work you may read. 
2. You must work until the teacher tells you to prepare to leave, the teacher  
dismisses you not the bell. 
3. Double check to make sure your assignment and information is written in  
your agenda. 
4. Clean up your space. 
5. Exit when the teacher tells you, in an orderly fashion. 
 
Policy Regarding Cheating 
**When a student is given an assignment (daily activity, quiz, test, etc.) that is to be completed independently; independent behavior is what is expected. Any other behavior will be considered cheating, and the student will receive a grade of zero for the assignment. 
 
Expectations: 
MRS. SEMTNER’S CLASS EXPECTATIONS 
 
1. Students will have homework in this class. The completion of homework is expected. When written homework is assigned it will be taken up by the teacher at the beginning of class the following day. 
2. Students are expected to be active learners in this class. This includes bringing necessary supplies to class everyday, participating in class discussions, taking thorough notes, reading, and studying. 
3. If a student is absent, the student will have five days in which to complete missing assignments. These assignments are expected to be turned in at the end of the five-day period. 
4. If a student is having trouble in science, after school help is available. The student is expected to make arrangements with the teacher in advance. Please do not wait until the last week of the grading period to ask for help. 
5. Supplies needed for this class are loose-leaf notebook paper, a Science notebook, an agenda, and #2 pencils. Students are expected to have these supplies in class everyday. 
6. Students are expected to have all supplies at their desks when they are needed. 
7. Good behavior and good manners are always expected in this classroom. Students will be treated with courtesy and respect. Students are expected to treat others in the same manner.  
8. Students are expected to do their best at all times. This includes academically and behaviorally.  
9. Students are expected to show respect to themselves, their peers, and all adults. Guests, who include substitutes, will be treated with the highest respect.  
10. Students are expected to be truthful and trustworthy. 
11. Students are expected to be active listeners. Active listeners look at the speaker. Active  
listeners are not engaged in other activities while someone is speaking. Active listeners  
are silent when someone is speaking to them. Active listeners can answer questions  
about what was said by the speaker. Active listeners are respectful. 
12. Students are expected to be positive. Put downs and negative comments will not be tolerated. 
 
Communication is a key factor in your child’s education. Feel free to contact me at KARASEMTNER@WALKERSCHOOLS.ORG I look forward to an awesome year! 
 
Kara Semtner 

Posted by: Team 7-2 Science

Congratulations to the 2010-2011 LMS Cheerleaders 
 
Draven Burrage 
Hayley Cochran 
Maegan Lamberth 
Catie Martin 
Kayla Richardson 
Cheyenne Roberts 
MaKenzie Tucker 
Chelsey Chastain 
Annsleigh Cole 
Hannah Durham 
Morgan Evans 
Aneetra Harris 
Kyla Holland 
Kayla Logan 
Brooke Meadows 
Savannah Neal 
Brittany Smith 

Posted by: Team 7-2 Science

The Scientific Method 
 
Georgia Professional Standards Addressed in this Lesson: 
S7CS4: Students will use tools and instruments for observing, measuring and manipulating equipment and materials in scientific activities. 
S7CS6: Students will communicate scientific ideas and activities clearly. 
 
Science is basically the process of observing things, asking questions about the observation and conducting experiments to find answers to the questions. 
 
Life Science - the study of living things. Life scientists conduct research or experiments that help in finding cures for diseases, conduct research to understand the components of cells, understanding how the living organisms in the environment effect each other as well as the forces or occurrences that impact living organisms. 
 
In order to do the work of scientists, the scientific method has been designed to break the process into stages. The scientific method is often described as a series of steps that is used to answer a question or solve a problem. 
 
There are six steps to the scientific method: 1) Ask a Question 2) Form a Hypothesis 3) Test the Hypothesis (Conduct Experiment) 4) Analyze the Results of the Experiment 5) Draw Conclusions and 6) Communicate the Results. 
 
Ask a Question 
When you observe something you do not fully understand you often ask yourself a question about what may have caused what you observed. Once you ask yourself a question, you must often do more observations while searching for the answer. 
 
Form a Hypothesis 
The hypothesis is a logical explanation for what you have observed. In other words you make a possible explanation to the phenomenon you observed. The hypothesis is usually written in the form of an If…,then statement. Example: If I take a balloon and fill it with air I can poke it with a sharp needle and then it will deflate very fast. This can be easily tested with a blown up balloon and a sewing needle. 
 
Test the Hypothesis 
When you test your hypothesis you are conducting experiments that may help you explain the phenomenon or observation. Many of the experiments scientists use are designed by the scientist working on solving the problem or phenomenon observed. This means that many scientists must be somewhat creative and often think “outside the box” to set up their experiments. 
 
When scientists test their hypothesis, they utilize controlled experiments. A controlled experiment is an experiment that tests only one factor at a time. The one factor being tested is known as the variable. Scientists only test one variable at a time to be more certain that it is the variable causing the effect. 
 
 
 
Analyze the Results 
After the experiments have been completed, the scientist must carefully analyze the results and determine if the results help in solving the problem or answer the hypothesis. 
 
 
 
Draw Conclusions 
The scientist must look at the data gathered from the experiments and draw a conclusion based on the results from the experiment. In other words, does my data support or not support the hypothesis that was formed. 
 
 
Communicate the Results 
This step involves telling others in the scientific field about your experiment and your findings. At this point other scientists may want to see if they can replicate you experiment or maybe modify your experiment to see if they come up with the same conclusion(s). 
 
Sometimes a problem may be tested over and over with scientists getting the same results. When this occurs, we call the explanation of why something occurs in a particular way a theory. 
 
Tools that Scientists Use 
Many of the tools scientists work with are often new and have been developed to work on specific research experiments. We often call this technology. Technology is the use of knowledge, tools, and materials to solve problems and accomplish tasks. 
 
One of the most common pieces of equipment for scientists to use is a microscope. Scientists use microscopes to see things in more or greater detail. There are two main types of microscopes scientists use: 1) Compound Light microscope and 2) Electron microscope. 
 
Compound Light Microscope – has three main parts (a tube with lenses, a stage and a light source). Specimens are often viewed with compound light microscopes that have been dyed (stained) in order to see the object better. The specimen or object is placed on the stage in order for the light to pass through it and as the image passes through the lenses, it becomes magnified. 
 
Electron Microscope – this is where tiny particles of matter (called electrons) are passed through (with a transmission electron microscope) or bounced off of the specimen (scanning electron microscope). A flat image is produced with the transmission electron microscope and a three dimensional image is produced with a scanning electron microscope. All organisms viewed with the electron microscopes must be dead because the electrons passing through them or bombarding them will cause death or mutations. 
 
Other Tools 
X Rays allow us to detect internal structures (broken bones) or living organisms. 
 
CT (Computed Tomography) Scans and MRI (Magnetic Resonance Imaging) these tools provide clearer images of internal tissues than X rays. These tools create images that experts can interpret. 
 
Computers are very prevalent in science. Computers now allow scientists to model different problems and modify the influences to see what results occur. You are probably familiar with computer generated weather forecasts if you watch the weather on nightly news. Computers are also one of the fastest methods for communicating, writing research articles for journals, calculating numerical data, and organize information to name a few uses. 
 
 
Systems of Measurement 
Scientists are constantly measuring things (temperature, mass, velocity, volume, and length to mention several). Scientists use the metric system to take measurements. For length we use the meter as the standard, for mass we use the gram as the standard, and for temperature we use Celsius, and for volumes of solids we use cubic units and for liquid volume we use liters. 
 
We must realize that each major unit has subunits based on the value of 10. Look at the following prefixes and know what they represent: (we will be using the prefixes with the standard length unit in this example) 
 
Kilo = 1,000 Kilometer = 1,000 meters 
Hecto = 100 Hectometer = 100 meters 
Deci = 1/10th Decimeter = 1/10th of a meter 
Centi = 1/100th Centimeter = 1/100th of a meter 
Milli = 1/1,000th Millimeter = 1/ 1,000th of a meter 
 
Most of these prefixes are also used with other measuring units. Example: Many times scientists need a liquid in small amounts so we measure it in milliliters (1/1,000th of a liter). We will practice with these in our homework/class work worksheets throughout the year. Remember to use the best suited unit for your measurements. We would not measure the length of a soccer field in millimeters normally, we would want it in meters. Small objects like algae or bacteria would not be measured with meters, but some subunit of meters like micrometers (1/100,000th of a meter). 
 
Measuring Area - area is the measurement of how much surface something has. We measure area with the following formula: 
Area = Length X Width or (L)(W) 
Notice that this will give us SQUARE UNITS. Example: If we have a rectangle that measures 3 meters in length and 2 meters in width, we can calculate the area of the rectangle by using our formula Area (A) = (L)(W) or (3)(2) which equals 6 SQUARE meters. 
 
Practice: Measure a regular sheet of notebook paper and calculate the square inches in centimeters. Answer: _________________ square centimeters (sq. cm.) 
 
Measuring Volume – volume is the amount of space something occupies or as in the case of a box, the amount of space it contains. We can calculate volume by using the formula as follows: 
Volume (V) = Length (L) X Width (W) X Height (H) 
Notice this will require a cubic unit on the answer. Example: If I have a plastic container that measures 4 meters wide, 6 meters in length and 2 meters in height, we can calculate the volume of water the container will hold. 
V = 4 meters X 6 meters X 2 meters which equals 48 Cubic meters 
 
Scientists often have specific tools to measure liquids. The most accurate tool is the graduated cylinder. It is a cylinder with marks (often in milliliters) that we will use in lab. When in class you can see one of the graduated cylinders on page 25 of your text book. 
 
Measuring Mass – mass is the amount of matter that makes up an object. The basic unit of mass is the kilogram. When we measure the mass of small items or organisms we may use milligrams, or in the case of our labs we usually measure in grams. The tool used to measure mass is the triple beam balance scale. We will use one of these in lab and you must know how to use it and read the scale. 
 
Measuring Temperature – temperature is the measure of how hot or cold something is. Temperature is really a measure of how fast or slow molecules are moving. The higher the temperature, the faster those molecules are moving. We measure temperature with a thermometer and in degrees Celsius. Celsius is the metric system’s unit of scale, while Fahrenheit is the unit we use in the United States. 
 
You should know that water boils at 212 degrees Fahrenheit, which is 100 degrees Celsius. Normal human body temperature is 98.6 degrees Fahrenheit, which is 37 degrees Celsius. Water freezes at 32 degrees Fahrenheit, which is 0 degrees Celsius. 
 
Safety – during science class this year we must observe safety rules. No horseplay will be allowed in the science room, no eating or drinking should occur. Always follow directions your teacher outlines and discusses. If you do not understand something, ask the teacher instead of “trying” something that could result in an accident. 
 
 
 

Posted by: Team 7-2 Science

 
State of Georgia: Seventh Grade Life Science Standards 
 
S7L1. Students will investigate the diversity of living organisms and how they can be compared scientifically. 
 
a. Demonstrate the process for the development of a dichotomous key. 
 
b. Classify organisms based on physical characteristics using a dichotomous key of the six kingdom system (archaebacteria, eubacteria, protists, fungi, plants, and animals). 
 
 
S7L2. Students will describe the structure and function of cells, tissues, organs, and organ systems. 
 
a. Explain that cells take in nutrients in order to grow and divide and to make needed materials. 
 
b. Relate cell structures (cell membrane, nucleus, cytoplasm, chloroplasts, mitochondria) to basic cell functions. 
 
c. Explain that cells are organized into tissues, tissues into organs, organs into systems, and systems into organisms. 
 
d. Explain that tissues, organs, and organ systems serve the needs cells have for oxygen, food, and waste removal. 
 
e. Explain the purpose of the major organ systems in the human body (i.e., digestion, respiration, reproduction, circulation, excretion, movement, control, and coordination, and for protection from disease). 
 
 
S7L3. Students will recognize how biological traits are passed on to successive generations. 
 
a. Explain the role of genes and chromosomes in the process of inheriting a specific trait. 
 
b. Compare and contrast that organisms reproduce asexually and sexually (bacteria, protists, fungi, plants & animals). 
 
c. Recognize that selective breeding can produce plants or animals with desired traits. 
 
 
S7L4. Students will examine the dependence of organisms on one another and their environments. 
 
a. Demonstrate in a food web that matter is transferred from one organism to another and can recycle between organisms and their environments. 
 
b. Explain in a food web that sunlight is the source of energy and that this energy moves from organism to organism. 
 
c. Recognize that changes in environmental conditions can affect the survival of both individuals and entire species. 
 
d. Categorize relationships between organisms that are competitive or mutually beneficial. 
 
e. Describe the characteristics of Earth’s major terrestrial biomes (i.e. tropical rain forest, savannah, temperate, desert, taiga, tundra, and mountain) and aquatic communities (i.e. freshwater, estuaries, and marine). 
 
 
S7L5. Students will examine the evolution of living organisms through inherited characteristics that promote survival of organisms and the survival of successive generations of their offspring. 
 
a. Explain that physical characteristics of organisms have changed over successive generations (e.g. Darwin’s finches and peppered moths of Manchester). 
 
b. Describe ways in which species on earth have evolved due to natural selection. 
 
c. Trace evidence that the fossil record found in sedimentary rock provides evidence for the long history of changing life forms. 
 
 

Posted by: Team 7-2 Science

Posted by: Team 7-2 Science

Posted by: Team 7-2 Science
Podcast: spiritcheercal.pdf

NOTES 
GPS: S7L2: Students will describe the structure and function of cells. 
GPS: S7L3(b) – compare and contrast sexual and asexual reproduction. 
 
Most organisms must eat other organisms in order to obtain energy for survival, but we have found some organisms that obtain their energy from hydrogen sulfide. These organisms are bacteria. Other organisms then feed on the bacteria. Not only are these bacteria found in deep ocean trenches and in Movile Cave that was discussed in your reading. 
 
PART 1 NOTES 
Every living thing has cells. Humans are composed of about 80 trillion cells. A cell is a membrane-covered structure that contains all of the materials necessary for life. 
 
Most cells are too small to be seen with the naked eye. Organisms with many cells have cells that carry out special functions. Example: Your nerve cells carry impulses to your brain. These impulses may be signals to walk, laugh, talk or be silent. 
 
All organisms have the ability to sense change in their environment and respond to that change. (Getting more cloths if you are cold, taking a sweater off if you are hot). 
 
Living organisms respond to change. 
 
A change in the organism’s environment that affects the activity of the organism is called a stimulus. (Plural - stimuli). 
 
Stimuli can be chemicals, gravity, darkness, pain, light, sounds, tastes, or anything that causes an organism to respond. 
 
Homeostasis 
 
The maintenance of a stable internal environment is called homeostasis. 
 
Even though an organism’s external environment changes, their internal environment must remain fairly constant. Example: the human body must remain at 37o Celsius. If it falls below this, we could go into hypothermia (hypo – below, thermia – temperature) or if it rises much above we could go into hyperthermia (hyper – above, thermia – temperature). Both of these conditions may result in death. 
 
**The maintenance of a stable internal environment is called homeostasis. 
 
If you are too hot, your body sweats. This is your body’s method to cool itself off and maintain homeostasis. If you are cold, your body shivers. This creates heat from the muscles and raises your body temperature to maintain homeostasis. 
 
Living Things Reproduce 
 
Organisms make other organisms like themselves. They can do this in one of two ways: asexual reproduction, or sexual reproduction. 
In asexual reproduction a parent produces offspring that are identical to the parent. (Hydra producing buds on page 38). 
 
In sexual reproduction, it requires two organisms to serve as parents to produce offspring, which will have traits from both parents. (Bears). 
 
Can you think of other asexual and sexual organisms? 
 
Living Things Have DNA 
 
The cells of all living things contain a special molecule called DNA (deoxyribonucleic acid). DNA provides the instructions to build the proper proteins in the organism. These proteins take part in the organism’s cells activities. 
 
The transmission of the characteristics from one generation to the next is called heredity. What are some traits you received due to heredity? 
 
Living Things Use Energy 
 
All living organisms must have energy in order to carry out daily activities. An organism’s metabolism is the total of all of the chemical activities that it performs. 
 
The cells in your body must transport materials into and out of them in order to remain alive. All of this requires energy and the total energy needs is your metabolism. 
 
Living Things Grow and Develop 
 
All living things, whether they are made up of one cell or many cells, grow during periods of their lives. (Single celled organisms have their cell get larger. Multi-cellular organisms add cells to become larger.) 
 
Organisms also go through different stages of development. Humans go through different stages as we develop. (Embryo, fetus, baby, child, adolescent, young adult, middle aged, senior citizen.) (An oak tree begins as an acorn, seedling, sapling, and then a tree)  
 
 
Review 
 
1. What characteristics of living things does a river have? Is a river alive? 
 
A river has energy (it moves – kinetic energy), and can grow larger (flooding). But it is not alive because it is not made of cells, cannot respond to stimuli, has no DNA, and cannot reproduce. 
 
2. What does a fur coat on a bear have to do with homeostasis? 
 
Homeostasis is the maintenance of a stable internal environment. The fur coat of a bear helps it keep a stable body temperature. 
 
 
3. How is reproduction related to heredity? 
 
Heredity is the passing of characteristics from parents to offspring. When organisms reproduce, offspring inherit copies of their parents DNA. 
 
4. What are some of the stimuli that you respond to in your environment? 
 

Posted by: Team 7-2 Science

1. Organism-a living thing. 
2. Cell-the basic unit of structure and function in living things. 
3. Unicellular-made of a single cell. 
4. Multicellular-consisting of many cells. 
5. Stimulus-a change in an organism’s surrounding that causes 
6. Response-an action or change in behavior that occurs in reaction to a stimulus. 
7. Development-the process of change that occurs during an organism’s life to produce a more complex organism. 
8. Spontaneous generation-the mistaken idea that living things arise from nonliving sources. 
9. Autotroph-an organism that makes it own food. 
10. Heterotroph-an organism that cannot make its own food 
11. Homeostasis-the maintenance of stable internal conditions in an organism 
12. Classification-the process of grouping things based on their similarities. 
13. Taxanomy-the scientific study of how living things are classified.- 
14. Binomial nomenclature-the system for naming organisms in which each organism is given a unique, two-part scientific name. 
15. Genus-a classification grouping that consists of a number of similar, closely related species. 
16. Species-a group of organisms that are physically similar and can mate with each other and produce offspring that can also mate and reproduce. 
17. Prokaryote-an organisms whose cells lack a nucleus and some other cells structures. 
18. Nucleus-the control center of a eukaryotic cell that directs the cell’s activities and contains the information that determines the cell’s form and function. 
19. Eukaryote-an organism whose cells contain nuclei. 
20. Cell-the basic unit of structure and function in living things. 
21. Microscope-an instrument that makes small objects look larger. 
22. Cell theory-A widely accepted explanation of the relationship between cells and living things. 
23. Organelle-a tiny cell structure that carries out a specific function within the cell. 
24. Cell wall-A rigid layer of nonliving material that surrounds the cells of plants and some other organisms. 
25. Cell membrane-the outside cell boundary that controls which substances can enter or leave the cell. 
26. Cytoplasm-the material within a cell apart from the nucleus. 
27. Mitochondria-rod-shaped cell structures that convert energy in food molecules to energy the cell can use to carry out its functions. 
28. Endoplasmic reticulum-a ell structure that forms passageways in which proteins and other materials are carried through the cell. 
29. Ribosome-a small grain-like structure in the cytoplasm of a cell where proteins are made. 
30. Golgi body-a structure in a cell that receives proteins and other newly formed materials from the endoplasmic reticulum, packages them, and distributes them to other part of the cell. 
31. Chloroplast-a structure in the cells of plants and some other organisms that captures energy from sunlight and uses it to produce food. 
32. Vacuole-a sac inside a cell that acts as a storage area. 
33. Lysosome-a small, round cell structure containing chemicals that break down large food particles into smaller ones. 
34. Biogenisis- theory that living things can come only from other living things. 
35. Phylogeny- evolutionary history of an organism used to group into kingdoms 
36. Dichotomous key- a tool that can be used to determine the identity of something by answering a series of paired questions.  

Posted by: Team 7-2 Science

NOTES: Copy and Paste these into a word document if you want to print them! 
 
Section 1 
Cells are similar to factories in that they must obtain materials form outside the cell membrane and remove material within the cell membrane. Food and liquids must be brought into the cell and wastes must be removes from the cell. All of this exchanging must be carried out across the cell membrane. 
 
Diffusion 
 
Particles are always moving whether they be in the form of a liquid, solid or gas. Particles naturally move from areas that are crowded to areas not as crowded. Stated scientifically we would say particles move from areas of greater concentration to areas of lower concentration. We call this process diffusion. Diffusion can occur across cell membranes or outside of the cell. Diffusion does not require any energy expended on the cell’s part. 
 
Diffusion of Water 
 
All living things require water. Recall that humans cannot survive except for about three days without water. Water is diffused through a cell membrane, but we call this process osmosis. Osmosis is the process by which water disperses from an area of high concentration to an area of low concentration. 
 
If we place a semi-permeable membrane between pure water and food coloring, what would happen? 
 
Semi-permeable membrane 
| 
Pure Water (100%) | Water (80%) 
| Food Coloring (20%) 
| 
 
In this situation we would have pure water “100%” in a higher concentration and it would flow to the area of lesser concentration (80%) until equilibrium were reached. 
 
Osmosis will occur across cell membranes also. This is why a wilted plant will become firm and erect when watered. The water will enter into the plant cell (area of lower concentration). 
 
Moving Small Particles 
 
Many substances can cross the cell membrane by diffusion and osmosis, but some may be too large to pass through the cell membrane. Recall that the cell membrane is a double layer of phospholipids. Embedded within the cell membrane, you will find some proteins that act as passageways into and out of the cell. Objects that are too large to directly pass into and out of the cell must enter or leave by way of these proteins. This can occur by passive or active transport. 
 
Passive Transport 
 
This occurs where the substance or particle entering or leaving the cell is too large to directly pass into or out of the cell. In passive transport, the particles travel from an area of higher concentration to an area of lower concentration by way of the embedded protein. The cell does not use any energy for this to occur. 
 
Active Transport 
 
In active transport, the particles flow in the opposite direction of diffusion. In other words, the embedded proteins transport the particles from lower concentration to areas of higher concentration. This process requires energy expended by the cell. This energy is ATP. An example of active transport could include sugar molecules needing to get inside a cell where the concentration is higher than the outside of the cell. 
 
Summing it up: Diffusion, Active Transport and Passive Transport are good methods to move small particles into and out of the cell. 
 
Moving Large Particles 
 
At times, large particles will need to enter and exit the cell. This can be done in two ways: endocytosis and exocytosis. 
 
Endocytosis – the cell membrane surrounds the large particle and encloses it to form a vesicle. The vesicle is “pinched off” inside the cell to be used. Remember: endo - into 
 
Exocytosis – This is carried out when a large particle must be removed from the cell. In exocytosis, the vesicles are formed at the endoplasmic reticulum or the golgi complex to carry the particles out of the cell. Remember: exo – exit. 
 
Review on your own: 
1). what is diffusion? 2). what is Osmosis? 3) How do cells take in large materials into the cell? 4). How do cells remove large particles from the cell? 5). Explain passive and active transport. 
 
Section 2 
 
Cell Energy 
 
All cells must have food in order to survive. When you feel hungry, your cells are telling you they need something to eat. 
 
Nearly all the energy for all life comes from the sun. Plants and some algae are able to capture this light energy and convert it into food through the process of photosynthesis. If we did not have plants and other producers, there would not be any consumers. 
 
Photosynthesis 
 
As we discussed in class, plants have molecules that are able to capture the energy of sunlight. These special molecules are called pigments. Most people have heard of the term chlorophyll, this is the molecule that can capture the sun’s energy and use the energy in the production of ATP. The chlorophyll is located in structures called chloroplasts. The chlorophyll is responsible for the colors we see in plant leaves/stems in most cases. 
Plants use carbon dioxide + water + sunlight to yield glucose and oxygen. 
The chemical formula will look like this: 
6CO2 + 6H2O + light energy -à C6H12O6 + 6O2 Glucose is a carbohydrate; this is a form of energy the plant can store. If a consumer eats a producer, the consumer can use the glucose as a source to be used for the production of ATP. Notice that photosynthesis also produces oxygen. We need oxygen to carry out our respiration processes. 
 
 
 
Getting Energy From Food 
 
Consumers must eat other organisms (plant or animal) in order to obtain food. This material can be broken down into a form of energy our cells can use. There are basically two methods to this: 1) cellular respiration and 2) fermentation. 
 
Cellular Respiration 
 
When we respire, we breathe. This means we take in a breath of air into our lungs and we exhale the waste gas carbon dioxide. This is respiration, but not cellular respiration. Cellular respiration is occurring at the cellular level. In general terms, our cells are taking the food in the form of glucose and breaking it down into carbon dioxide and water and releasing energy. This energy being released is in the form of heat. Most of this heat is used to maintain homeostasis (37 degrees Celsius). Some of the energy is stored in the form of ATP. The ATP can be used to carry out biological functions of the cell (we will discuss this in detail later). All of this cellular respiration is occurring in the organelle called the mitochondria. 
 
Summarizing: Glucose + Oxygen à Water + Energy (ATP) 
This is the reverse of what? That’s correct, photosynthesis. 
 
Fermentation 
 
This is essentially the partial breakdown of glucose in the absence of oxygen. When you run and your muscles begin to ache, you are experiencing a type of fermentation. The aching is lactic acid building up within your muscles. Another type of fermentation occurs when yeast cells are mixed with flour and water (making dough). The yeast cells will begin to break down the glucose and give off carbon dioxide gas. This is what causes bread dough to rise. 
 
Fermentation is also used to produce alcohol products. Yeast is added to some form of sugar and as the yeast break down the glucose they give off carbon dioxide and produce ethanol. The percent of ethanol being formed is what finally kills the yeast cells. (Example – winemakers press the sugars out of the grapes and the yeast cells will begin to ferment the juice into wine. Once the wine gets to a certain percent alcohol it becomes toxic for the yeast and they die. 
Section 3 
 
Cell Information 
 
The cell goes through a cycle during its life. The cycle begins when a new cell is made and that new cell goes through specific stages or phases and divides to form new cells. 
 
Before cells can divide to produce new cells, they must make copies of their DNA. Recall that DNA is the hereditary information or genetic information that contains all the information to produce proteins. The DNA is in the form of structures called chromosomes. We can recognize the phase that a cell is in during cell division by looking at the chromosomes and where they are located during the division process. We will look at these phases shortly. 
 
Division of Prokaryotic Cells 
 
Recall that bacteria do not have a nucleus and the DNA is in an oval pattern and is not complex. The bacteria also do not have organelles that are enclosed by a membrane. These are the main reasons that bacteria or prokaryotic cell division is simple compared to eukaryotic cells. Essentially the DNA is copied and the bacteria cell divides with each new cell receiving one copy of the DNA. This division process is known as binary fission, of prokaryotic cells. 
 
Division of Eukaryotic Cells 
 
Recall: Eukaryotic cells are much larger than prokaryotic cells and they are more complex. They have a nucleus and organelles that are enclosed within membranes. The nucleus is where the DNA is “housed”. 
 
The number of chromosomes in organisms has nothing to do with the complexity of the organism in eukaryotic cells. Example: Fruit flies have 8 chromosomes, humans have 46, and potatoes have 48. So is a potato more complex than a human? Don’t answer that! (Joke). If the number of chromosomes determined the complexity, the potato would be more complex. Chromosomes are lined up into pairs. Each chromosome in each pair is similar to each other. 
 
 
 
 
General Eukaryotic Cell Division 
 
The eukaryotic cell cycle has three main stages. The first stage involves the cell growing and copying organelles and chromosomes. The duplicated chromosomes are called chromatids. The chromatids are held together in the center by a centromere (disk shaped structure). Imagine two pieces of wire the same length and same diameter laying beside each other. Then picture the wires joined in the center with a disk of glue. This is essentially what the chromatids look like. 
 
The second stage of eukaryotic cell division involves the chromatids separating. When the chromosomes separate, the process is known as mitosis. This separation stage or mitosis ensures the new cells each get a copy of each chromosome. 
 
During the third stage of the cell cycle, the cell divides and two identical cells, called daughter cells, are formed. 
 
Specifics of Eukaryotic Cell Division 
 
Interphase – this is the phase before mitosis begins. During this phase, all of the DNA and organelles are copied and the cell is preparing itself to enter the mitosis phases. 
 
Mitosis Phase 1 called prophase. During prophase, the DNA begins to “twist” together and darken within the cell. (Imagine tiny, thin fibers twisting. These fibers will become thicker, shorter and more visible. This is similar to what the DNA or chromosomes are doing during prophase). The nuclear membrane breaks apart and organelles known as centrioles move to opposite ends of the cell. A “spindle” made of protein fibers is formed between the two centrioles. 
 
Mitosis Phase 2 called metaphase. During metaphase, the chromosomes line up on the spindle of the cell and are located at the equator of the cell. 
 
Mitosis Phase 3 called anaphase. During anaphase the spindle fibers begin to shorten and the chromosomes attached to the spindle begin to move away from the equator with one pair of chromosomes moving toward the poles or to the centriole location. 
 
Mitosis Phase 4 called telophase. During telophase the cell begins to divide into two cells. Close to the equator of the cell, the cell begins to “pinch inward. This area is called the cleavage furrow. This is the location where new cell membranes will be forming for each cell. Now mitosis has completed and we must discuss the last phase of cell division. 
 
The last phase of cell division is called cytokinesis. During cytokinesis, the cytoplasm divides and the new cell membranes completely form and the result is two identical cells called daughter cells. These cells are genetically the same as the original cell that we started with. At this point the new cells are starting their life cycle or cell cycle. 
 
Plant versus Animal Cell Division 
 
Recall: Plant cells have a cell wall and a cell membrane. During telophase in plant cells, instead of a new cell membrane forming at the cleavage furrow, a cell plate is formed. The cell plate will form the cell membrane of the two new plant cells. After this, a cell wall will form between the two membranes to complete cell division of the plant cell. 
 
Notes adapted from Robert Littlejohn 

Posted by: Team 7-2 Science

Section 1: Body Organization 
 
Recall: The maintenance of a stable internal environment is called homeostasis. If homeostasis is not maintained, cells are often damaged and can die from the damage. These cells make up tissues, so in effect the tissues can die and as the organization levels occur, the organism can ultimately die. 
 
Tissue Types 
 
There are four types of tissue: 1) Epithelial Tissue – this tissue covers and protects underlying tissue 2) Nervous Tissue – this tissue sends electrical signals from the point of a stimulus to the brain in order to react to the stimulus if necessary 3) Skeletal Muscle Tissue – this tissue is made of cells capable of contracting and relaxing that can produce movement within or of our body 4) Connective Tissue – this tissue joins, supports, protects, insulates, nourishes, and cushions organs and keeps organs from falling apart. 
 
Recall that two or more tissues working together will form an organ. Our stomach has all four types of tissues that make it up (the stomach therefore is an organ). The stomach has blood vessels which is connective tissue, it contains epithelial tissue to cover the lining, it has nervous tissue (tell us when we are hungry or full), and it contains muscle tissue that expands and contracts to break up the food we ingest (eat). 
 
Recall organs make up organ systems. When any organ fails, the body’s organ systems can fail. We have 11 organ systems. 
 
The 11 Organ Systems (We will look at these in great detail) 
 
1: Integumentary System – made up of our skin, hair and nails. This system helps protect underlying tissue(s). 
 
2: Muscular System – Your skeletal muscles move your bones and this allows us to move from one place to another if our body is functioning properly. 
 
3: Skeletal System – this is made up of your bones. Our bones provide support. If we didn’t have bones we would be one ugly blob with no shape. 
4: Cardiovascular System – composed of our heart, and blood vessels (arteries and veins). Transports blood with nutrients and wastes. 
 
5: Nervous System – this system sends electrical impulses throughout our body (nerves, spinal cord, and brain). 
 
6: Lymphatic System – this system includes lymph nodes and lymph vessels and helps us with immunity and getting rid of germs. 
 
7: Digestive System – Breaks down food we eat into nutrients that our body can use. 
 
8: Endocrine System – Composed of glands that secrete hormones (chemical messages) for specific actions in our body (pituitary gland, thyroid gland and testies for males, and ovaries for females to name a few of the glands in our body). 
 
9: Respiratory System – our lungs absorb oxygen and release carbon dioxide. 
 
10: Urinary System – removes wastes from our blood and regulates fluids in our body. 
 
11: Reproductive System: In males it produces and releases sperm. In females it produces eggs and provides a development site for an unborn baby. 
 
Review 
 
1. Explain the organization level and relationship between cells, tissues, organs, and organ systems. 
 
2. Compare the four types of tissues and their function. 
 
3. Without looking at your notes, make yourself a chart listing all of the major organ systems and their function. 
 
Answers to Review 
1. Cells make up tissues, tissues make up organs, organs make up organ systems and organ systems is what make up an organism. Cells work together to make tissues. Tissues work together to make organs. Organs work together to make organ systems. Organ systems make up organisms. 
2. Nervous Tissue – sends electrical signals (impulses) for stimuli, Epithelial – covers and lines in order to protect underlying tissue, Muscle – cells contract and expand to produce movement, Connective Tissue – joins, supports, protects, insulates, nourishes, cushions, and keeps organs from falling apart. 
3. Compare your chart to the notes you have learned. 
 
Applying what you learned 
Think of a time when homeostasis in your body was disrupted. Which body system(s) were affected? Explain your reasoning. 
 
IMPORTANT: As we learn details about each system always make yourself learn the NAME, LOCATION, and FUNCTION. Example: Name: nervous system, Location: spinal cord, nerves, brain, Function: to send electrical impulses for reactions to stimuli or other needed reactions (walking, talking, etc.). 
 
Section 2 
 
The Skeletal System 
 
Our bones and cartilage and the special structures that connect them make up our skeletal system. If we did not have our skeleton for support we would be a mass or blob so to speak. Our skeleton or bones are living cells. They must be nourished because they are made up of cells. These special cells are called osteocytes and they mage up our bone tissue. 
 
Functions of Our Bones 
 
1) Protection - the vital organs in our chest (heart and lungs) are protected with our ribs, our spinal cord is protected by our vertebrae, and our brain is protected by our skull. 
2) Storage - bones store minerals that help the nerves and muscles function properly. Your arm and leg bones store fat that can be used for energy. 
3) Movement – Muscles pull on the skeleton in specific locations to produce movement. Without the bones we also could not sit, stand, walk, or run. 
4) Blood Cell Formation – Some of our bones are filled with marrow that produces blood cells. 
 
Bone is composed of connective tissue and minerals that are deposited by living cells called osteoblasts. If we looked at a section of our longest bone (the femur) in our thigh, we would find spongy bone and compact bone. These are found in all of our long bones. Compact bone is dense and has no visible openings. Spongy bone appears to look like a real fine sponge with air spaces. Spongy bone is where we get most of the strength for our bones. The “spongy” configuration acts as a truss structure analogous to what we would see in a building made of steel. 
 
Marrow 
The soft tissue in the bone is called marrow and red marrow produces red blood cells.Yellow marrow found in the center of the bone (central canal) of long bones stores fat. The canals in the compact bone contain small blood vessels. 
 
Bone Information 
 
Most bones start out as soft, flexible tissue called cartilage. As a new born baby, we had very little bone. We were mostly cartilage. As we became older, the cartilage was replaced by bone. 
 
The location where two or more bones connect is called a joint. These joints have unique designs that will allow movement from some joints and little or no movement from others. Joints that are freely moving are more susceptible to injury than those that are less flexible. 
 
Joints are held together by ligaments that are connecting bone to bone. A strained ligament will heal if given time, but a torn ligament must be repaired surgically. Most bones also have cartilage on the ends to help cushion the area where two bones meet. When this cartilage is worn away, the joint becomes arthritic. This can create discomfort for the individual with arthritis. 
 
 
Types of Joints 
 
1. Sliding Joint – this type of joint allows some movement of flexibility. The bones in this type of joint glide over each other. Example: the bones in your wrist. 
2. Ball and Socket – this operates like a joystick on a computer game, the joint is free to move in all directions. Example: your shoulder joint. 
3. Hinge Joint – this operates like a hinge on a door. Example: Knee joint, knuckles, toes, jaw and elbow joint. 
 
 
How Bones Function to Help Movement 
 
Bones function like a simple machine called a lever. The lever has three parts: fulcrum, effort, and the load. The effort is the force applied to the lever, the fulcrum is the pivot point and the load is the resistance.  
 
Review 
1. What are the important functions of bones? 
2. Draw a long bone like a femur that has a section removed and label the parts (spongy bone, compact bone, areas for blood vessels, marrow cavity, and cartilage). 
3. List three hinge joints in your body. 
4. Are bones living? What do bones begin as? What do we call the cells that deposit bones? Where are red blood cells produced? Some bones store fat, what is it used for? 
5. What is a function of cartilage on the ends of bones? 
 
Answers 
 
1. Bones provide support, store and release minerals, enables us to move our bodies, and make blood cells. 
2. Compare your drawing to the bone on page 527 in our classroom text. 
3. Hinge joints can include the elbow, knee, jaw, knuckles and toes. 
4. Bones are living, they require nourishment like other tissues in our body. Bones start out as cartilage. The cells that deposit bones are called osteoblasts. Red blood cells are produced in the red marrow. The fat can be used as a source for energy. 
5. Cartilage can serve as a cushioning source when it is located at the end of long bones. 
 
Section 3 
 
The Muscular System 
 
Muscles attach to bones and the connective tissue that attaches them make up the muscular system. Remember: Muscles ALWAYS contract to do work. In other words, for muscles to do work, the muscle fiber must contract (get shorter). 
 
Types of Muscle Tissues 
 
1) Smooth Muscle – this is found in the digestive tract and your blood vessels. 2) Cardiac Muscle – this is heart muscle (found only in the muscle tissues of your heart). 3) Skeletal Muscles – these are the muscles attached to your bones for movement and protecting inner organs. 
 
Voluntary or Involuntary Muscle 
Muscles that are under your control are voluntary muscles. The muscles used to pick up a pencil when you want to write are voluntary muscles (you are controlling their actions). Muscles that digest food, move food through your digestive system (smooth) and cardiac muscles are examples of involuntary muscles (you do not have to think about making these muscles take action). 
Some may fall into voluntary and involuntary (example: eyelids – sometimes you control your blinking, other times you blink and do not realize you have blinked). 
 
Working Muscles 
When you want your muscles to contract and make you walk you must have electrical signals traveling from your brain to your muscle cells. The muscle cells respond by contracting (shortening). Remember, muscles only do work when their fibers are contracting. 
 
Muscles to Bones 
Your skeletal muscles are attached to your bones by a connective tissue called tendons. When the muscles contract, they get shorter and bring the bones closer to each other, hence producing movement. 
 
Muscles always work in Pairs 
Muscles work in pairs, resulting in smooth controlled movements. Example: Your Biceps (upper arm muscle in the front) can contract and cause our arm to bend at our elbow. The triceps (back of upper arm) can contract to straighten our arm back out. The muscle that is causing the bending movement is called the flexor, and the muscle that straightens out a part of the body is called the extensor. So in the above example, the biceps is the flexor and the triceps is the extensor. 
Use It or Lose It 
If you do not use your muscles, the muscle tissue will deteriorate. We must use our muscles in order to keep them “tone” and in order to build them up and become stronger. If you know someone with a broken bone and they wear a cast, the muscles not being used will become weaker and will have to be strengthened when the cast is removed. 
Muscles also aid in the circulation of blood and lymphatic fluid. When muscles contract, the action constricts the vessels and “pushes” blood and lymph in their respected vessels. This helps blood flow without extra effort from the heart. 
 
Exercise 
In order to maintain muscle or build muscle, we have to be active and exercise. The most effective exercise is resistance exercise. This is where the muscle contracts to move an object and the object offers resistance. The process of lifting our bodies vertically offers one method of resistance. An example of this type of exercise would include climbing steps, push-ups, sit-ups, pull-ups and other motions that use our own weight as the resistance weight. Resistance exercises are often hard to maintain long periods of time, but they offer one of the best methods of building muscle. 
 
Aerobic Exercise 
Aerobic – with oxygen. Aerobic exercise is great for our cardiovascular system. This strengthens the heart muscle and will increase the lung capacity and the effectiveness of our lungs. Aerobic exercises do not necessarily strengthen skeletal muscles, but increases our endurance. 
 
Damaging Muscle Tissue 
Before taking part in any physical exercise program, our muscles need to be warmed and stretched. Stretching can do this. Taking in deep breaths while stretching also increases the oxygen content in our bodies. After stretching and giving our muscles a warm-up reduces the chance for a muscle injury. When we “pull a muscle” we may be straining it or the muscle fibers can actually tear. We can also damage tendons. The tendons can become inflamed (irritated) and the area may feel warmer than the surrounding tissue. This type of tendon injury is called tendonitis. 
 
Anabolic Steroid Use 
This has become all too common in the area of sports. Taking the anabolic steroids can make our muscles larger and stronger and gives many athletes an unfair advantage. We are now seeing the effects of using anabolic steroids. Many athletes have died from having an enlarged heart as well as other complications from using anabolic steroids. If a person has not fully developed it may also cause bones to stop growing, high blood pressure, kidney failure and liver and heart problems. Anyone taking these steroids are at risk for an early death or a very unhealthy life due to the negative affects. 
 
Review 
1: What are the three types of muscle tissue and give a few locations you can find each type. Give the main functions of each type of muscle tissue. 
2: What are the differences and similarities between resistance and aerobic exercising and give a few examples of each. Can they both be the same in certain instances? 
3: Describe or explain how the muscles in your arm allow you to pick up a glass from a table to your mouth for a drink. 
 
Answers: 
1: Smooth muscle tissue helps move materials through the digestive tract and blood vessels; cardiac muscles cause the heart to beat; and skeletal muscles enables bones to move. 
2: Resistance exercises increase our strength of skeletal muscles. Resistance exercises involve overcoming weight of some type. Aerobic exercises improve the condition of heart muscle and increase our endurance. 
3: Our biceps contract in order for our arm to bend and bring the glass up to our mouth to drink. Our triceps contract in order to straighten our arm back out and set the drink back onto the table. 
 
Section 4 
 
The Integumentary System 
 
The integumentary system is for protection and includes our hair, nails, and skin. Our skin is the largest organ of all the organs our bodies have. Integumentary means covering. The integumentary system also helps your body to maintain homeostasis. Remember from chapter 1: homeostasis is a stable internal environment. 
 
 
 
 
Functions of the Skin 
1) Protects our bodies from evaporation and helps keep foreign particles out of the body. 
2) Keeps us in “touch” with our environment. The nerve endings in our skin allow us to fell what is around us. 
3) Our skin helps to maintain our body temperature. We have sweat glands in our skin that will sweat and when the sweat evaporates, it cools our body. 
4) Our skin also helps rid our bodies of waste products from the blood stream by way of the sweat. 
 
Skin Color 
A pigment in our skin called melanin determines the color of our skin. If we have a lot of melanin, our skin is very dark. If a small amount of melanin is produced, our skin will be very light. Melanin in the upper layer of the skin protects us by absorbing much of the ultraviolet radiation from the sun, which reduces the DNA damage that can lead to cancer. All of our skin is susceptible to cancer so protection should be taken when we spend time outside. Proper skin suntan lotion should be used and the lotion should contain a SPF protection of at least 30. 
 
Layers of Skin 
The skin is the largest organ of our body and it has two layers. The epidermis is the upper layer and is thinner than the second layer. “Epi” means above or top. The deeper layer is called the dermis. It is thicker than the epidermis. 
 
Epidermis 
Composed of epithelial tissue. It is about as thick as two pieces of notebook paper over the most of our body. Our palms of our hands and soles of our feet have thicker layers of epidermal cells. Most epidermal cells are dead and filled with keratin which helps the skin be tough and water-proof. 
 
Dermis 
Found beneath the epidermis. It contains many connective tissue fibers called collagen. This provides strength and allows the skin to bend without tearing. 
 
 
 
Hair and Nails 
Hair is grown from the hair follicle and the portion we see is actually dead cells. As hair grows from the follicle, cells are pushed up and form the portion we see. 
 
Hair protects us from ultraviolet radiation and also helps keep dust and other particles out of our eyes and nose. Hair also helps maintain internal body temperature. Many mammals rely on their hair to keep them warm in very cold climates. Humans form “goose bumps” on our skin when we get cold. This occurs when a muscle connected close to the hair follicle contracts and the hair stands up in an erect position. The erected hairs act like a sweater to trap heat which warms the body. 
 
Our nails protect the ends of our toes and fingers so they can remain sensitive to touch. Our nails grow from nail roots. The nails we see are dead cells. As cells grow from the root, the nail gets longer. 
 
Skin Cancer and other Problems 
Sometimes skin cells become damaged and the cells rapidly multiply out of control. When cells go through the cell cycle at a rate faster than normal we call that cancer. This can also invade other tissues and result in cancer spreading. 
 
A common problem many individuals face is having hormones cause too much oil being produced by the skin cell oil glands and creating a situation for infections. The oil may cause skin cells and bacteria to clog up the follicle and when the bacteria multiply you have an infection. Washing our skin well each day can usually prevent this type of infection. 
 
REVIEW 
 
1: Why does skin color vary from person to person? 
2: List as many structures as you can that are found in the skin and give the function of each one. 
 
ANSWERS 
1: The amount of melanin produced regulated the skin color. 
2: Hair follicle, blood vessels, nerves, oil glands, sweat glands, keratin for water proofing and flexibility, fat cells to help conserve temperature and can be used as energy sources if needed. 

Posted by: Team 7-2 Science

 
Chapter 6 Genes and Gene Technology 
 
Section 1 
 
We now know that genes can be passed on from one generation to another. Genes are located on chromosomes. Chromosomes are made of protein and DNA eoxyribonucleic acid). 
 
What must Genes be able to do? 
 
Genes must be able to do two things: 1) supply instructions for cell processes and for building cell structures, and 2) must be able to be copied each time a cell divides, so that each cell contains an identical set of genes. 
 
What are Nucleotides? 
 
Nucleotides are the subunits that make up DNA. There are four subunits that make up these nucleotides. Each nucleotide consists of three different types of material; a sugar, a phosphate, and a base. All nucleotides are identical except for their base. The four bases are: adenine, thymine, guanine, and cytosine. Each of these has a slightly different shape. The bases are usually referred to by the first letter in their name. Example: Cytosine = C, Guanine = G, Thymine = T and Adenine = A. 
 
Chargaff’s Rule 
 
Erwin Chargaff discovered that the amount of adenine is always equal to thymine and the amount of guanine is always equal to that of cytosine. When Chargaff released his finding, no one knew what to think about them, but as we later learned he was correct. 
 
 
 
Rosalind Franklin (Women in Science) 
 
Rosalind Franklin was studying DNA molecules and used X-rays to get an “image” of what DNA looked like. She reported that DNA looked like a coil or spiral shaped (like a twisted ladder). 
 
Watson and Crick 
 
James Watson and Fredrick Crick were two scientists also studying DNA molecules and trying to determine what DNA also looked like. James Watson did not give much attention to Rosalind Franklin’s idea about the shape of a DNA molecule, but Fredrick Crick respected her work and continued to look into Rosalind Franklin’s findings. Guess What!? Rosalind Franklin was correct. As Watson and Crick soon found out, DNA did look like a twisted ladder. Watson and Crick called their model a double helix. 
 
What is the Structure of DNA? 
 
Picture in your mind a ladder. The “handrails” contain the sugar and phosphate components of the nucleotide and the “rungs” (places where you would position your feet to climb a ladder) is where the bases are located. Remember that the bases are of a specific shape and adenine and thymine always pair up and cytosine and guanine always pair up. So if we have GGATC on one side of the ladder composing half the rung, the other side must contain CCTAG to compliment or match up to the bases on the other side of the ladder. 
 
Why is Making Copies of DNA Important? 
 
It is important to make copies of DNA because DNA is used to make proteins. We call this coping process replication. DNA replicates by splitting down the middle (imagine cutting a ladder in half at the rungs, or a zipper being unzipped down the middle). As the DNA strand is “unzipped”, one half of the strand must be used for copying or act as a template or pattern for a new complimentary side. Try your skill: What is the complimentary copy for the bases GCGGTCCAAAT? If you chose CGCCAGGTTTA, then you are correct. 
 
What order can the bases occur? The bases can occur in any sequence depending on the protein that needs to be produced. The order of the bases supplies the information on how to make each protein and/or trait the cell needs. 
 
DNA has the same bases in all organisms, the difference is how the bases are arranged in their order. So, all organisms have DNA that consists of the same bases (from bacteria to dogs, snakes, alligators, fish or what ever organism you want to name). Remember though that the order makes all organisms different from each other. All organisms are similar in that they have DNA, but all are different in the order the bases occur or the sequence the bases are arranged. 
 
 
 
Recall: Gregor Mendel conducted research that identified how genes are passed from parents to offspring or one generation to the next. We only discussed the possibility of having dominant or recessive traits, but there are always a few exceptions to the rule. 
 
Incomplete Dominance 
 
During Mendel’s research, he did not find any traits that “blended” together, but there are occasions where two or more genes affect the trait being looked at. In other words, one trait is not dominant over another, but they both have influences. This is known as incomplete dominance. 
 
Example: There is a flower called the snapdragon. In the Red flower form, the alleles are R1R1. In another form the flower is white and the alleles are represented as R2R2. Try crossing R1R1 X R2R2. If you did your Punnett Square correctly, you should know that all four of the possibilities for the cross are R1R2. When you have these alleles in the snapdragon, the result is a pink flower (both the white alleles and the red alleles have an affect and the result is pink). This is a good example of incomplete dominance  
 
Weird Gene Expression 
 
Sometimes some genes may affect more than one trait. Our book discussed a white tiger. The gene that influences the white fur color also influences eye color and white tigers have blue eyes. 
 
 
 
In humans, eye color is often affected by more that one gene. Different shades of blue or green eyes are two examples. With this example, the different colors are due to different amounts of pigment present. 
 
Can the Environment have an Influence on your Traits? 
 
Oddly enough, the environment can have an effect. Let’s find out how. Suppose you have the traits to be tall. If you do not get the proper nutrition or nutrients, you may not reach your full height potential that your genes are programmed for. Another example, you may have inherited specific genes for a talent, but if you do not practice your talent will not develop to the potential you have inherited. 
 
 
 
Review Section One 
 
 
 
1. What are the subunits that make up DNA? 
 
2. What are the components that make up nucleotides? 
 
3. What shape did Rosalind Franklin say the DNA molecule was in? 
 
4. What did James Watson and Fredrick Crick confirm? (shape) 
 
5. What makes all organisms have something in common? 
 
6. I have extracted the DNA from a cell and determined there was 43 percent guanine in the DNA. What percent of cytosine must be present? 
 
Answers to Review Section One 
 
 
 
1. The subunits of DNA are nucleotides. 
 
2. The compounds that make up nucleotides are phosphate, a sugar and the base (cytosine, guanine, adenine, thymine). 
 
3. Rosalind Franklin determined the shape was a coiled or a spiral shape. 
 
4. Watson and Crick confirmed that the shape of the DNA molecule was a double helix (looks like a twisted ladder). 
 
5. All organisms have DNA and this makes them have something in common, but the bases are not in the same sequence and this causes them to be different. 
 
6. There has to be 43 percent of cytosine because the amount of cytosine must equal the amount of guanine and the amount of adenine must equal the amount of thymine. 
 
 
 
Practice, More from reading! 
 
1. Why did scientists think that proteins instead of DNA carried genetic information? Answer: Because proteins are much more complex than DNA. 
 
2. What is incomplete dominance? Answer: In incomplete dominance, each of the two alleles that determine a trait has it’s own degree of influence. 
 
3. True/False: Tigers with white fur are probably going to have blue eyes. If you said true, you are correct! 
 
4. If a person inherits a gene to be tall, that person will be tall no matter what. Is this statement true or false? 
 
5. If we found the bases AATACGTTC, what would be the complementary base chain? If you said TTATGCAAG you are correct. 
 
6. We can relate to the shape of DNA if we can picture a twisted ladder (True or False). True, it is also called a double helix. 
 
7. Food for thought: If we took the entire DNA in your body and stretched it out, it would stretch from the Earth to the Sun and back two times…. Wow, that is some length!! 
 
 
 
Funny Time: Why did the mutant chromosome go to the tailor? 
 
 
 
Because it had a hole in its genes! 
 
 
 
Section 2 
 
How does DNA Work? 
 
Scientists knew that the DNA held some sort of code that told the cell what to do, but they wanted to “break the code” in order to understand the instructions better. 
 
 
 
Genes and Proteins 
 
Scientists discovered that the sequences of the bases in the DNA strand read like a book. Each set of three bases made up the “word” that coded for a specific amino acid. RECALL: Amino acids are the building blocks of proteins. So DNA tells our cells what proteins to make. Let’s find out how. 
 
 
 
The order of the bases determines the order of the amino acids in a protein. Each gene is a set of instructions for making a protein. Why are proteins so important? Because proteins are found throughout the cell and serve as chemical messengers. They also help determine how tall you will grow, what color your eyes are, if you are colored-blind or not, if your hair is curly or straight. These are a few examples of the importance of proteins. 
 
 
 
The three bases that code for a particular protein is called a codon. A messenger carries the DNA half of strand with the codons out into the cytoplasm from the nucleus and into a ribosome. At the ribosome site the ribosome attaches the amino acids into the proper sequence to form the appropriate protein. Essentially, the ribosome is the “factory” where the proteins are made. 
 
Changes in Genes 
 
Genes are specific in the proteins they produce and the codons must occur in the proper order or a problem may result. Sometimes extra bases can be added, subtracted, or substituted and problems may occur. These problems are called mutations. 
 
Mutation Types 
 
If a base is left out, the mutation is called a deletion mutation. If a base is added (where we now have an extra base) it is called an insertion mutation. If there is a base substituted for another base we call it a substitution mutation. 
 
Example: 
 
 
 
Normal Base Pair Sequence: AACCTTGGA 
 
TTGGAACCT 
 
 
 
Base has been removed: ACCTTGGAA 
 
TGGAACCTT 
 
 
 
Base is added: AAACCTTGGA 
 
TTTGGAACCT 
 
 
 
Base is substituted: AACATTGGA 
 
TTGTAACCT  
 
If any of the changes occur, a mutation results. The mutation may not have any affect on the organism, or it could cause harm to the organism to the point that death results. Mutations do happen, but we are very fortunate that many of these mistakes are repaired in the cell, but sometimes the mistakes may not be repairable or they are not 100% repaired. A third situation that can occur if a mutation happens in sex cells is the mutation can be passed on to the next generation. 
 
What can damage DNA? 
 
Anything that can damage DNA is called a mutagen (capable of causing a mutation). Some examples that you may have heard of before are high energy radiation, ultraviolet radiation, chemicals (asbestos and benzene are two), and cigarette smoke to name some common mutagens. Can you think of others? 
 
Specific example of a substitution Mutation 
 
The bases GAA are the code for an amino acid called glutamic acid. If GTA occurs, it codes for an amino acid called valine. When valine is substituted in the wrong place for glutamic acid it can cause a blood disease known as sickle cell anemia. This effects the red blood cells. Normally the red blood cells are round and have a concave side on each side. When an individual has sickle cell anemia, the red blood cell is the shape of a crescent moon (or a sickle used to harvest grain). This causes trouble for the red blood cell to pass through the blood vessels. The sickle shape can cause the vessels to become blocked and is very painful. 
 
 
 
What is a Pedigree? 
 
A pedigree is a tool that can be used to map out a family’s genetic traits and determine the probability of the trait being passed on through generations. If a dangerous mutation has occurred in a family, the scientists and doctors may want to see if the mutation has occurred before and determine the probability of it occurring again if the couple wants to have more offspring. 
 
Selecting Genes for Specific Reasons 
 
Some genes may be selected for during crossing some plants or breeding some organisms. Scientists may want a type of agricultural grain to be resistant to certain fungi and if they can cross specific resistant grains, they can create a variety that will withstand becoming infected with the fungus. 
 
Creating Specific Traits by Inserting Genes on Purpose 
 
 
 
Scientists have also learned how to insert specific traits into a DNA strand. This can be controversial. Do we want to allow scientists to create organisms with specific traits that normally would not occur in nature? An example we read about in the book included scientists inserting a tobacco plant with some DNA from a lightening bug (firefly) and the result is a tobacco plant that grows. 
 
 
 
This is known as genetic engineering. Do you think genetic engineering is okay to carry out? Why or why not? 
 
 
 
What is we can identify a gene that will cure certain diseases if we allow scientists insert the gene into a strand of human DNA. Is this morally correct? Is it humanities duty to carry this type of research out? 
 
 
 
Review Section 2 
 
1. List and explain all three types of mutations. 
 
2. What type of mutation did we discuss that causes a disease in the blood of humans, what is the disease called? 
 
3. How is genetic engineering different from selective breeding? 
 
4. What is the function of ribosomes (this should be a review)? 
 
5. What are some examples from the environment that can cause mutations? 
 
Answers: 
 
 
 
1. Insertion – an extra base is added, Deletion – a base is deleted, Substitution – a base is substituted for another base. 
 
2. Substitution mutation is responsible for sickle cell anemia. 
 
3. Selective breeding involves selecting specific traits and breeding organisms that have those traits. Genetic engineering involves changing the DNA in the DNA strand of an organism. 
 
4. Ribosomes are the “factories” to make proteins. 
 
5. Ultra-violet radiation can cause skin cancer and this is because the cells DNA become mutated and the cell begins to divide faster than it normally would. Cigarette smoke is another example. The chemicals, asbestos and benzene can cause certain types of cancers due to the mutations they cause. 
 
 
 
Study/Review Sheet for Chapter 6 Section 1 
 
1. Chromosomes are made up of proteins and __________. 
A. DNA C. Ribosomes 
B. Nucleus E. Lipids 
 
2. DNA is made up of units called ________________. 
A. Genetic Tablets C. Nucleotides 
B. Identical Partners D. Double Nitrogens 
 
3. Adenine, Thymine, Cytosine, and Guanine are found on ________________. 
A. The surface of our cells. 
B. The nucleus cells in the nervous system 
C. The nucleotides that make up our genes. 
D. There are not such things as adenine, thymine, cytosine, and guanine. 
 
4. Each nucleotide consists of three different types of material. What are they? 
_________________, ________________, and _________________. 
 
5. There are four possible bases in a nucleotide, what are the names of each of the bases? 
____________________, _________________, __________________ and _______________________________. 
 
6. The bases found in nucleotides are always paired up. Adenine is always paired with _____________________ in DNA and Cytosine is always paired up with _____________________________. 
 
7. Our textbook gives an artists rendition of the shapes the nucleotides may occur. Draw the examples given from page 128. Do you notice how these could fit together? 
 
 
 
 
 
 
8. ____________________ _____________________ is the lady who used X-rays to create images of DNA molecules. 
 
9. James ________________ and Francis _______________ modeled DNA and determined the shape must be a _________________ _________________. 
 
10. Describe and draw a double helix DNA molecule. 
 
11. Draw the DNA molecule with at least 10 base pairs correctly matched (your drawing on this portion can be as if the DNA molecule appeared exactly like a ladder). 
 
11. Make sure you understand that one side of the DNA molecule is complimentary to the other side regarding the bases that pair up. 
 
12. When a DNA molecule makes a copy of itself it “unzips” resembling a zipper or an upside down Y. When DNA makes a copy of itself we say it ________________ or has undergone replication. 
 
13. The DNA molecule splits down the middle where the _______________ meet when it replicates. One side is used as a template or pattern to form a new complimentary side. 
 
14. When DNA replicates itself and no mutations have occurred, the two new DNA molecules are _________________ to each other. 
 
15. Remember: DNA functions in the same way for all organisms. The same bases are found in all organisms, but it is the __________________ in which the bases occur that makes all organisms different from each other. 
 
16. Sometimes one allele may not be completely dominant over another allele and the result is that both alleles play a role in the phenotype (recall phenotype: what the organism looks like or the appearance of an organism). When two or more alleles have their own degree of influence, we say the alleles exhibit ____________________ dominance. 
 
17. What are two examples given to demonstrate incomplete dominance in organisms that we read and discussed? Explain this concept in terms of the white tiger and snapdragon flower. 
 
18. We have discussed how alleles/genes can influence your development. Explain how our environment can influence our development. 
 
Chapter 6 Section 2 Review/Study Questions 
 
1. The bases adenine, thymine, cytosine, and guanine make up the _________________ of the code in DNA. 
2. Each __________ bases code for a specific amino acid. 
3. __________________ are made up of amino acids linked together (we have had this before). 
4. The ____________ of the bases determines the order of the amino acids in a protein. 
5. Scientists thought or DNA was found in proteins at one time because proteins are so ________________. 
6. The first step in making a protein is copying the _______ strand that contains the code for the gene (protein) wanting to be made. 
7. The “factory” where proteins are assembled is the _______________ (this is a review from cell organelles). 
8. Sometimes there are mistakes that occur during the gene making process. These mistakes are known as ________________________. 
9. The cause for a mutation is a change in the sequence of _________________ in the DNA. 
10. If a base has been mistakenly left out, this type of mutation is known as a _______________. 
11. If an extra base has been included into the code, this mutation is called a ________________ mutation. 
12. If a base has been replaced by a different base in the code, this type of mutation is known as a _________________. 
13. There are three possible outcomes to a mutation. One is it has no effect at all on the organism. The second possible outcome could result in a harmful change, and the last possibility is the mutation occurs in the sex cells and is passed from one ____________________ to the next generation. 
 
14. DNA can be damaged by several means. Anything that can damage DNA is known as a _______________. 
 
15. High-energy radiation, X-rays, and ultraviolet radiation can all cause ______________ and are classified as _____________________. 
 
16. Notes to know: Many chemicals are mutagens and have been placed on lists giving specific warning to avoid direct contact with these chemicals. It is very important to read the manufacturers labels on chemicals because you will find the important directions and warnings located here. 
 
17. A specific example of a substitution mutation is when valine is substituted for glutamic acid. The resulting substitution results in a red blood cell problem called _________________ cell anemia. Draw what a sickle cell would look like and explain some of the problems associated with sickle cell anemia. 
 
18. A tool used for tracing a trait through generations of a family is called a _________________. 
 
19. Most disorders resulting from mutations are recessive, therefore they only show up when both alleles for the trait are _________________. 
 
20. The process that scientist use to transfer genes from one organism to another is called __________________ engineering. 
 
21. When scientists breed (mate) organisms for desirable characteristics or to create a new breed, they often use ________________ breeding. 
 
Adapted from Robert Littlejohn 

Posted by: Team 7-2 Science