Biology EOC review

answers

Ch 1: scientific method1. A2. D3. D4. B5. C

11. C12. C13. B14. C15. C6. C

7. D8. C9. A10. D

16. D17. B18. D19. D20. B

21. A . State the problem (in question form) B. Collect information about the problem C. Form a hypothesis (a possible answer) ( must be testable) D. Design and conduct an experiment (use an experimental group with a variable, and a control group without the variable.)E. Record observations and dataF. Check results; redo experiment as neededG. Draw your conclusions (accept or reject hypothesis)H. Communicate your results.

22. Hypothesis is a possible answer, or an educated guess.

Theory is a general statement supported by many scientific observations and experiments, and represents the most logical explanation of the evidence.

23. A research plan is necessary before testing a hypothesis to ensure that there is only one variable, and that there are valid controls.

24. A clear statement of a hypothesis is important because it could lead to the answer of a question.

25. A scientist can collect and organize data in tables, charts, and graphs

26. The results of one experiment cannot become a theory; a theory must be supported by MANY experiments and observations.

27. B

28. control group: solution with no salt experimental group 1 5% salt experimental group 2 10% salt experimental group 3 15% salt

two conditions constant: water temperature, number of shrimp, amount of solution in containers

29. C (D)

30. C

31. -hypothesis: if we grow the plants in acidic soil, they will be a different color.

-The control group will be grown in (normal) slightly basic soil.

-Both the experimental and control groups should be in the same amount of soil, should receive the same amounts of water and sunlight.

-one piece of evidence supporting my hypothesis would be flowers that

were a color (not white)

32. Corn seedlings are only one type of plant, so to make generalizations about plants, many types should be studied.

33. It is important to include all steps of an experiment so that other researchers can repeat it and verify the results

34. A hypothesis should be changed whenever new, conflicting information is found

35. Charles Darwin kept a journal so that he could keep track of all details and data, as well as new ideas.

36. -Question: can seeds travel long distances in the ocean and still able to grow?-Hypothesis: If I soak seeds in salt water, and then plant them, they will grow. -Experiment: he soaked many different kinds of seeds, for short and long periods of time, and then planted them.

Chapter 2: Laboratory tools and techniques

1. C2. B3. B4. D5. B

6.D7.C8.D9.C10.D

11.D12.D13.D14.A15.C (A)

16.A (and B)17.A18.A19.D20.B

21. C

22. C

23. A

24. D

25. A 10-ml graduated cylinder, should be read at eye-level, to the bottom of the meniscus

26. Measurements are useful for accuracy so reliable, valid, information can be obtained and analyzed to draw conclusions.

27. Scientists use tools and instruments to improve the accuracy of their observations.

28. A. Use a medicine dropper to place a drop of water on the slide.B. Use the medicine dropper to place the specimen into the water on the slide.C. Gently lower a coverslip, one edge down at a 45-degree angle firstD. Add a drop of stain at one edge , and draw it through with a piece of paper towel.

29. Similarities: both are used to magnify images more than 250,000 times, and they use electron beams and magnetic lenses.Differences: the TEM passes beams through a specimen. The SEM passes beams over the surface.

30. volume: literstemperature: degrees Celsiusmass: kilogramslength: meters

31. (safety rules)

32. They could rub a piece of each food on a piece of brown paper bag and look for grease.

33. Scientists have used electron microscopes to see much smaller objects.

34. Both types of microscopes are used to magnify small objects. Light microscopes can be used to see living objects; electron microscopes can be used to see much smaller objects, because no light is involved.

35. Don’t bother.

Ch 3: Organic Molecules: from Atoms to Cells

1. B2. D3. B4. A5. D6. B7. C

8. D9. B10.A11.A12.C13.A14.A

15.B16.B17.B18.A19.B20.D21.B

22. To maintain high levels of organization necessary to stay alive, organisms require energy.

23. Carbon is of special importance to living things because organic compounds are built on a “skeleton” or framework of carbon atoms.

24. Four important functions of organic compounds are: capturing and transforming energy, building new structures, storing materials, and repairing structures.

25. Athletes need lots of complex carbohydrates during training to supply energy.

26. C

27. B

28. They have different amino acid sequences, and different conformations.

29. C

30. Three important characteristics of proteins:a. Made of subunits called amino acidsb. Main functions are to build new materials, transport substances, send signals, provide defense, control chemical and metabolic activitiesc. Structure and function is determined by the sequence of the amino acids, and the conformation (shape) of the molecule.

31. The particular proteins in our body depend upon our DNA, because the nucleotide sequence determines those proteins.

32. Tissues are groups of cells, such as nervous tissue that is made up of nerve cells or neurons. Organs are made of tissues working together, such as the brain which is made of nervous, blood, and connective tissues.

33. Main levels of organization: atoms, molecules, organic compounds, organelles, cells, tissues, organs, organ systems, organisms.

34. Evolution explains the problems with weight loss in that a favorable adaptation would be the ability for a person’s metabolism to slow down when facing starvation. Also, a person whose fat cells have been emptied will feel hunger and try to “fill them up” again.

34. Exercise is a healthier way to lose weight because it increases the amount of energy used by the body. It also increases the amount of muscle tissue, which burns more calories than other types of body tissues even when resting.

34. Anorexia and bulemia both are both eating disorders that result in severe weight loss, which may be fatal. Anorexia is a refusal to eat, whereas bulemics eat and then eliminate the food. Anorexics appear unhealthy, while bulemics may appear healthy.

Chapter 4: Homeostasis and Enzymes

1. B2. B3. A4. A5. A6. B7. D8. A

9. A10. A11. B12. D13. A14. C15.A

16. B17. A18. C19. B20. C21. B22. A23. C

24. ribosomes: where proteins are builtlysosomes: break down foodmitochondria: release energy from foodnucleus: information storage, control centergolgi apparatus: packages many materialsvacuoles: store materials such as food or

wastechloroplasts: convert sun’s energy into food

25. The cell membrane is selectively permeable because it allows some substances to pass through but not others.This is important because cells need certain molecules inside but some should be kept outside.

26. Arrow A shows molecules going from an area of less concentration to an area of greater concentration, which is active transport because energy is needed to go against the concentration gradient. Passive transport is different in that it doesn’t need energy.

27. Receptor molecules, proteins on the surface of a cell membrane, allow certain molecules to attach (chemical messengers) thereby enabling communication between cells.

28. Stability in an organism is maintained by integration or making all body parts work together, and control or acting in an organized and appropriate manner. In animals, this job is done by the nervous system and the endocrine system.

29. Cells communicate with each other by having certain chemicals move in or out of them. Receptor proteins in the cell membrane act as docking sites for these chemicals.

30. Every nerve cell does 3 things; it receives, conducts, and sends nerve impulses.

31. A nerve impulse is the movement of electrical voltage (energy) changes along the length of a neuron. The cell membrane is the most important part of this because electrical voltage is created by the rapid movement of positive ions across a cell membrane. These changes trigger changes further along the membrane.

32. When a nerve impulse reaches the end of a neuron, it causes the release of chemicals, which diffuse across the space to the next cell (the synapse) to the next nerve cell, which causes the impulse to be carried along.

33.

34.The energy stored in chemical bonds can be transferred to other newly formed chemical bonds or released as heat or light. Cells use this energy for active transport, heat, or other cell functions.

35. If a cell’s mitochondria were removed, it would not be able to release energy from food molecules

36.The spleen was removed to cure leukemia

36.The pancreatic tissues were used for research; they produced a certain protein which was later used to make a new medicine.

36.The legal system was used to determine whose rights should have precedence, those of the cell-donor or the researchers.

Chapter 5: Homeostasis and Enzymes

1. C2. C3. A4. B5. D6. C7. C8. B

9. D10. C11. B12. C13. B14. B15. B16. B17. D

18. A19. D20. C21. B22. D23. C24. B25. B26. A

27. A28. C29. C30. D31. C32. C33. B34. A

35. Being multicellular increses and organism’s ability to maintain homeostasis and survive because it has many different structures and systems to protect it from external changes.

36. A body cell will be more likely to survive than an amoeba because the body cell is multicellular.

37. Intercellular fluid is important for homeostasis because many substances are dissolved in it, and it allows substances to be exchanged between cells and blood in the capillaries.

38. B

39. A feedback mechanism has 3 parts:• a sensor – something that can detect a change• a control unit – something that can recognize the correct

level of something• an effector-something that can make changes

40. • Blood sugar level is too high• pancreas releases insulin (hormone) into blood stream• insulin reduces levels of glucose• blood sugar levels are too low• pancreas releases glucagon to raise blood sugar levels

41.When we exercise, there is an increase in the CO2 levels in the blood and intercellular fluid, released by muscle cells breaking down organic compounds for energy. A structure in the brain detects these increased levels in the blood passing through the brain, and in the fluid around the brain cells. The brain sends signals to the chest to increase the rate of breathing and the amount of air taken in with each breath. These changes increase the levels of gas exchange in the lungs, lowering the levels of CO2 in the blood. These lower levels are then detected in the brain, reversing the other responses.

42.D

*43. Rising external temperatures will be detected by sensors in the skin, which will send a message to the brain, which will increase blood vessel dilation and sweating. Homeostasis means that the body must maintain constant internal temperatures, regardless of what is happening outside the body.

44. Staying in the shade prevents the body from heating up too much in the sun.

45. Stomata, or openings, surrounded by guard cells on the surface of a leaf, control the loss of water. When water is abundant, the guard cells fill (by osmosis) and open to allow water to evaporate. When water is scarce, they lose water, and close, preventing water loss.

46. Contractile vacuoles and guard cells both help maintain levels of water within organisms.

47. Four organ systems used in homeostasis:• Excretory system: removes wastes and

regulates the chemistry of the body’s fluids• Nervous system: uses electrochemical

impulses to regulate body functions• Endocrine system: produces hormones

(chemical messengers) that help regulate bodily functions

• Immune system: defends the body from dangerous substances and harmful microorganisms.

48. D

49. If the temperature of the solution was increased, the rate of the reaction would slow down, because enzymes need a certain temperature to function.

50. A person with a high body temperature would possibly die because enzymes change their shape if the temperature changes, and therefore their function.

51. We must maintain a neutral pH because any changes affect an enzyme’s shape and its function.

52. Life on the ISS is different from Earth in that there is no downward pull from gravity. There is no up or down, no floors or ceilings. Crews live in a relatively small space, and sleep wherever they feel comfortable .

53. The effects of weightlessness are interesting to scientists because we are not aware of our bodies’ responses to gravity until we leave the Earth.

54. Some of the adaptations of the body to living in a world with gravity include use of signals from our eyes, from the fluid-filled tubes in our ears, from pressure receptors on the bottoms of our feet, and from the distribution of liquids in blood vessels.

Chapter 9: Classification

1. B (domain) 9. C 17. B2. D 10. B3. C 11. D4. C 12. C5. C no 13.6. D 14. C7. D 15. C8. B 16. D (domain)

18. Prokaryotes – no nucleus; no organelles -carry out processes in their cell

membranes, simpler processesEukaryotes – nucleus; organelles

-carry out processes in specific organelles, more complex

19. C20. Leopard – hair; no organism has hair

before leopard, after it is no tail which doesn’t describe the leopard

21. A dichotomous key asks pairs of questions, of which only one applies to each organism and directs you to the next question in order to narrow down which organism has the traits being observed.Ex.: Leopard: Does it have hair? Or does it not have hair?

22.Pollen is released into the wind – only male gameteCoral release both eggs and sperm into the water

23. Genetic recombination = variation24. Amount lost to predation is lessened

Chapter 10: Evolution

1. D 9. B 17. A2. D 10. C 18. B3. D 11. B 19. D4. C 12. A 20. D5. C 13. C 21. C6. D 14. B 22. B7. B 15. D 23. C8. C 16. A 24. D

25. Through genetic variation and natural selection, new species have developed which are fit for their environment.

26. There is always competition for resources, which means that the organisms best adapted will survive.

27. Variations allow for new traits to develop, which can lead to evolution of the population

28. Radiation and chemicals, and mistakes in replication; gametes.Body cells would not pass on their DNA to offspring.

29. Water, food, mates. The animals with the traits that allow them to get the resources will survive and reproduce, while the animals without those adaptations will not.

30. D31. Chromosomes from 2 parents instead of

one increase variation, as well as crossing over and independent assortment. More variation means more traits available in population. Some traits will be adaptations helping the organism survive.

32. Creates variation in a population.33. B34. Natural selection includes the other

three. In order for natural selection to occur there must be competition (struggle for existence) and variation in the population. Also, the environment must change in order for new traits to be selected for.

35. In a population, some individuals get separated and form their own population in a different location. If the new environment is different than the original environment, individuals with the traits best adapted for the new environment will survive and reproduce. Ones without these traits will die off. Eventually, the new population is different enough from the original population that they are reproductively isolated and therefore a new species.

36. The bacteria that had some immunity to the antibiotic survived and reproduced and eventually the population became large enough to make the patient sick again.

37. B38. Adaptation: trait that helps an organism survive

in its environment; Speed of cheetahs. Can chase down its prey.

39. Some insects had the genes to be resistant to the pesticide. They survived and reproduced. Eventually the entire population had the genes to resist the pesticide.

40. Good news: cures bacterial infectionsBad news: Overuse causes antibiotic

resistant strains of bacteria41. Because it is causing strains of bacteria to

evolve which are resistant to most commonly used antibiotics. Also, those resistant bacteria may be found in the food.

42. Natural selection explains that the overuse of antibiotics causes the resistant bacteria to be selected for and to reproduce causing more dangerous infections.

Chapter 11 Evidence for Evolution

1. D2. A3. A4. C5. C6. D

7. A8. D9. C10.A11.A family tree, like an evolutionary

tree, can shows ancestral relationships.

12.Fossils are usually formed when sediments bury an organism, and their remains (hard tissues)are gradually replaced by minerals. Or, the body of a plant or animal can form an impression in soft clay or mud, which hardens.

13.Similarities in the biochemistry of proteins can be useful in determining evolutionary relationships because by studying amino acid sequences scientists have learned that small differences show a close relationship.

14. B15. An “evolutionary bush” would be a better way to

diagram an evolutionary path because there is rarely a straight lineage. Organisms often evolve differently, as in the adaptive radiation of the Galapagos finches.

16. C17. A vestigial structure suggests that an ancestor

having the structure would have used it. ie. Appendix

18. D19. Natural selection would explain the change in

percentage of each color moth. As the environment changed, different colors would be selected (eaten).

20. C

21. Galapagos finches moved to different islands, with different climates and food supplies. Individuals having traits that were helpful to each particular environment survived and reproduced.

22. B23. B24. DNA nucleotide sequence is important all organisms

store genetic information in DNA. The similarities in DNA sequences show close relationships.

25. Mitochondrial DNA comes only from your mother.26. Scientists have used mtDNA to study the origins of

human history.27. Mitochondrial Eve has been shown to be the ancestor

of all humans alive today, but scientists differ on her age. Mungo man has no mtDNA relationship to Mitochondrial Eve, which has raised new questions about human origins.

Chap 12: Mechanisms of Evolution

1. A2. B3. C4. A5. B6. B7. D

8. D• C• B• D• D• C• A

15. Evolution happens in response to changes in the environment, so since the environment is always changing, evolution is ongoing.

16. B17. The adaptive value is determined by how helpful an

adaptation is to survival. For example, dark color of moths is not an adaptation unless the forest tree trunks have been darkened by soot.

18. Penguins that had the characteristic of liking to huddle together would tend to live longer and produce more offspring, who would also probably have the trait. Over time, most penguins have this behavior.

19. See # 18.

20. A

21. B

22. C23. C24. A25. B26. Organisms having variations that help them

survive will survive and pass on their traits to the next generation. If environmental conditions change, organisms having helpful traits will survive, and over time the species will change. Environmental changes are usually gradual. However, if the changes are in the nature of a catastrophe, such as a meteorite or flood, there is not enough time for any evolution to occur. For example, the wooly mammoths died because there was no food.

27.Farmers do not like prairie dogs because they interfere with the planting of crops. Ranchers don’t like them because their tunnels could cause grazing animals to fall and break legs. Black-footed ferrets eat prairie dogs, but when prairie dogs are poisoned, the ferrets die too.

28. In 1987 scientists captured the 18 ferrets to breed them and re-populate the area.

29. If prairie dogs are protected, there will be a poison-free source of food for ferrets.

Chap 13: DNA and heredity

1. B2. D3. B4. C5. C6. D7. C

8. B9. B10.B11.A12.A13. C14.D

15.A16.B17.C18.A19.B20.D

21.To do its job, genetic material must be

* able to store enough information to make another organism

* able to make a copy of itself again and again

* strong and stable enough to not fall apart easily

* able to mutate slightly from time to time to provide variations

22. Cytosine and guanine pair togetherAdenine and Thymine pair together

23. Crick & Watson described the basic structure of DNA as a double helix; the double strand is like a ladder, with nucleotide bases forming the rungs, and sugar and phosphate groups forming the sides.

24. Because DNA is made of only 4 different nucleotides, it was thought to be too simple to contain the code of life. But using the 4 different letters to make long sequences, nature can create an almost unlimited variety of genetic messages.

25.C26.D27.Genetic information is coded in the DNA

“alphabet.” The sequence of nucleotides determines subunits called amino acids; the amino acid sequence determines the protein; the protein determines the trait.

28.B29.C30.C31.T A A C T G G C32.B

33.DNA is an important molecule because it carries on life itself; all life is dependent upon it.

34.DNA nucleotides separate and act as templates in replication.

35.DNA molecules replicate by unwinding and acting as a template. Enzymes help match up free-floating nucleotides with their appropriate complementary nucleotides on the template. Identical new strands are formed and then released.

36.Box A should be a nucleotide, which acts as a template because it can only pair with one other (complementary) nucleotide.

37.B proteins38.Mutations can be helpful, as in the ability

to resist a disease, or harmful, as in loss of some ability.

39.Scientists originally thought repetitive DNA was “junk” because they did not understand its functions.

40.C

41.Telomeres are of interest because they may control the lifespan of a cell.

42. When a telomere gets very short the cells stop dividing.

43. The enzyme telomerase can reverse the shortening process by adding more telomeres.

44.There is great interest in the enzyme telomerase because it may have to do with cancer.

45.There is great interest in the absence of telomerase because it may have to do with aging.