Exam 1 Q3 Review Sheet
AP Biology
Exam 3Q3 will cover:
Chapter 11: ALL
Chapter 12: ALL
Chapter 13: ALL
**IGNORE ALL QUESTIONS PERTAINGING TO RTKS (Receptor Tyrosine Kinases)
Questions that will be on the exam:
1. For the “essay” question you will need to explain how gametes are made from a single somatic
diploid cell (meiotic cell division ). You will be required to draw and label a cell for each
subphase (G1,S,G2,PI,MI,AI,TI/cytokinesis, PII, MII, AII, TII/cytokinesis) similar to pages 244
and 245. Make sure you draw the final gametes. Do not leave them hanging in TII/cytokinesis.
Because meiosis II happens twice at the same time, you only need to draw it once and say that is
happens twice, once per daughter cell of meiosis I. Under each image should be a set of bullets
describing what is happening in that image. You need only label a structure once. Practice and
figure out the best way to draw this. You may want to bring colored pencils/pens or use different
shapes for chromosomes.
(The following terms should be included: haploid, diploid, synapsis, tetrad, homologous
chromosomes, crossing-over, centrosomes, mitotic spindle, kinetochores, motor proteins,
centromere, microtubules, metaphase plate, sister chromatids, chiasma, recombinant
chromosome, meiosis I and associated subphases, meiosis II and associated subphases,
chromatin, nuclear envelope, tetrad, sister chromatids, daughter chromosomes, MTOC,
microtubules, spindle fibers, poles, cleavage furrow, centrioles, aster, ATP, plasma membrane,
DNA replication, centrosome replication)
2. You will be asked to identify the ploidy of cells or draw cells of a specific ploidy
3. You will be asked to write out all possible gametes of various genotypes.
4. You will also be asked to draw out a very simple form of meiosis showing both independent
orientation and nondisjuntion of a specific number of chromosomes like diploid n=2, diploid n=4,
etc…
5. Make sure you can follow the number of chromosomes and amount of DNA in each stage of
mitotic and meiotic cell division.
CHAPTER 11 – Cell Communication
1. Explain communication between mating yeast (Figure 11.2)
2. Describe how cells communicate through direct contact (Figure 11.3).
3. Compare and contrast Paracrine, Synaptic and Hormal Signaling (Figure 11.5) – how are
they similar/different – describe each.
4. Identify and describe the three stages of cell signaling for both a hydrophilic molecule
(ligand) and a hydrophobic molecule (ligand). You should be able to explain why two
different signaling methods evolved. Give examples of ligands that would fall into each
category.
5. What is a ligand?
6. Make sure you can do every question in the chapter including the concept check
questions. I always pull a test question from these. This goes far all chapters.
7. Insulin receptor is an RTK. Starting with insulin, describe how the binding of insulin (the
ligand) to the insulin receptor results in a cellular response (Combine Pg 207 with Figure
11.8).
8. Starting with a growth factor (ligand) binding to a GPCR (7TM receptor) explain two
ways by which a cellular response might ensue depending on the cell type / type of
growth factor (combine pg 206 with Figures 11.9 and 11.10; combine pg 206 with
Figures 11.11 and 11.12). Make sure all the bold words in these sections are included in
your description.
9. More specific: Starting with epinephrine (aka adrenaline; a small hydrophilic hormone)
secreted by the adrenal glands under a stressful fight or flight situation, explain how this
results in the breakdown of glycogen in the liver and a subsequent rise in blood sugar to
make sure your cells have enough available energy for you to try and survive. Use Figure
11.13.
10. Explain signal amplification (Figure 11.13).
11. Explain how a hydrophilic growth factor can tell a cell to express a set of genes as the
cellular response (Figure 11.14).
12. Explain how the set of proteins a given cell expresses results in the specificity of cellular
signaling. Basically, how can the same hormone result in two cells having completely
different cellular responses. For example, adrenaline will result in the liver breaking
down glycogen, an increase heart rate, constriction of blood vessels and dilation of air
passages all at the same time (Figure 11.15).
13. Explain how ion channel receptors are used to transmit signals across a membrane
(Figure 11.7 on pg 208).
CHAPTERS 12 and 13
1. Identify the two most important functions of all organisms.
2. If the genes of an organism code for RNA/proteins that build an organism that cannot survive
or reproduce, what is the fate of those genes? What does this tell you about your genes?
4. Humans have a special skill that no other organism on the planet has. This skill is thought to be
the key to our success in terms of our cooperating with each other even though we are not closely
related. What skill am I referring to? Why do no other organisms cooperate with non-kin (nonrelated members of their species)? Why are we able to?
5. Identify the two parts of the life cycle. Draw a simple picture showing the human life cycle. Be
sure to include the ovum, sperm, zygote, fertilization, mitotic cell division, meiotic cell division,
haploid, diploid, n, 2n, n=23, n=46 and the number of chromosomes the cells have.
6. Explain how asexual reproducing organisms generate diversity. Compare this to the way
sexually reproducing organisms generate diversity. Why is maintaining genetic diversity one of
the most important functions of life?
7. Compare asexual to sexual reproduction. Include the advantages and disadvantages of both,
how the offspring compare to the partent(s) genetically, number of parents, types of organisms
that use each, etc…
8. Explain what is meant by evolutionary tradeoff and give examples including an example
relating to question 7.
9. Explain why in sexual reproduction, the offspring look so different to the parents as compared
to the offspring of an asexual parent.
10. Define cell theory. Who are credited with this theory?
11. Describe how prokaryotes divide as compared to eukaryotes. What is the name given to this
type of division?
12. Cell division refers to both mitosis (mitotic cell division), which is a small part of the cell
cycle, and meiosis (meiotic cell division), which is not part of the cell cycle because it is not a
cycle. Explain what I mean by it not being a cycle.
13. Mitotic cell division is not only used for reproduction. Identify all of the other functions of
mitotic cell division discussed in class. When is it used for reproduction?
14. Identify the name of the special type of mitotic cell division used by such organisms as yeast.
How does this differ from mitotic cell division in organisms like humans?
15. In class we found out that bacteria and other single celled protists and fungi are not the only
organisms that can reproduce asexually. Some plants and animals can do this as well. What is the
process called in plants and give an example? How is asexual reproduction accomplished in
animals?
16. In class we briefly mentioned regeneration. This is NOT reproduction. Regeneration is the
growing back of a lost part of the organisms like when a starfish grows back an arm that it lost.
This is obviously growth and required mitotic cell division. Why is this not reproduction?
17. Why do cells divide?
18. What is the eukaryotic cell cycle? If a cell with 46 chromosomes goes through the cell cycle
once, how many cells will result and how many chromosomes will each cell have? How do the
chromosomes in the new (daughter) cells relate to the chromosomes in the original (“parent”)
cell?
19. What must all cells do before they can divide and what is the name of the enzyme that is
involved in performing this function (HINT: S phase)?
20. Describe the molecular structure of DNA (parts of the nucleotide, how nucleotides attach, 5’
and 3’, the two strands, anti-parallel, etc…)
21. What is Chargaff’s rule?
22. Explain how 6 feet of DNA can be packaged into a nucleus with a diameter of 1/100th of a
millimeter.
23. Compare the extended form of DNA to the condensed form. At what stage in the cell cycle
would you find each?
24. Know the difference between the terms DNA, chromosome, and chromatin.
25. Describe the chromosomes found in the human nucleus (how many, which are homologous,
autosomes, sex chromosomes, etc…)
26. In terms of chromosomes, how are males and females different?
27. In class we concluded that we have at least two of every gene. Explain why.
28. We said that if the gene for hemoglobin were located on chromosome 11 there would be
another hemoglobin gene located at the same loci (position) on the other chromosome. These
genes would be similar, but not identical. Why?
29. Where does each homologous chromosome of a homologous pair come from?
30. Compare autosomes to sex chromosomes.
31. Describe which chromosomes (in humans) would be found in the sperm? In the ovum?
Remember: the sperm can have two different combinations.
32. Who determines the sex of the offspring in humans, the male or female? Explain.
33. Compare haploid to diploid. What do these terms refer to? Which cells inside us are haploid
and which are diploid? (We have two types of cells, the gametes = sex cells, and somatic cells =
body cells. The prefix soma- means “body”.)
34. If a cell is 2n, is it haploid, diploid or triploid? Explain.
35. If the haploid number of an organism is 38 (n = 38), how many chromosomes would be in its
body (somatic) cells.
36. If a triploid (3n) organism has a haploid number of 20, how many chromosomes would be
found in its somatic cells? How many chromosomes would be in a single set?
37. Do the ploidy problems on the website (notes sections).
38. What is a gene? What do genes code for directly (do not say polypeptides or proteins)? How
long are genes on average? How long are chromosomes? How many genes per chromosome?
How long is the human genome? How many of each gene do you have? How does this relate to
being diploid? How many genes do our cells have approximately?
39. What is the haploid number of humans? What about dogs?
40. When a chromosome is replicated in S phase the result is two sister chromatids attached by a
centromere. How do sister chromatids compare to each other? When is this structure present in
the cell cycle?
41. After S phase, how many chromosomes are there? How much DNA is there relative to before
S phase? After cytokinesis, how many chromosomes does each new cell have? How much DNA
does each new cell have compared to before and after S phase?
42. What must happen to the sister chromatids during the cell cycle? Why does this make sense in
terms of what the cell is trying to accomplish?
43. How is mitosis different from cytokinesis?
44. Cytokinesis is different in plant and animal cells. Explain how they are different and why they
need to be different. Compare the cleavage furrow to the cell plate.
45. Make sure you identify the subphase of any cell I show you in mitosis.
46. We discussed that the point of no return in the cell cycle is the passing of a cell from G1 into
S phase. Explain why.
47. Cells that are not dividing are typical stuck in what part of the cell cycle? Why would this
make sense?
48. Describe the structure of a pair of centrioles. How does this compare to a basal body?
47. Describe the structure of the centrosome. What is the function of the centrosome during
mitosis? What about during G1 (a normal functioning cell)?
48. Be able to draw and label a cell for each subphase of the cell cycle
(G1,S,G2,P,M,A,T/cytokinesis) similar to pages 222 and 223 of the textbook. Under each image
should be a set of bullets describing what is happening in that image. You need only label a
structure once. The cell will be diploid and have a haploid number of 2 (n=2).
(The following terms MUST be included: interphase, mitotic phase, mitosis, cytokinesis, G1, S,
G2, prophase (early and late), metaphase, anaphase, telophase, nulcear envelope, plasms
membrane, nucleolus, chromatin, centromsomes, centrioles, asters, spindle fibers, mitotic spindle,
chromosome, sister chromatids, sisters, centromere, kinetochore, MTOC, DNA replication,
metaphase plate, microtubules, daughter chromosomes, poles, cleavage furrow )
I put some mitosis videos up on the website under the misc. section.
49. Explain why the cell cycle needs to be regulated.
50. What is a tissue culture hood and tissue culture flasks used for?
51. What does the word nutrients refer to for us as chemoheterotrophs?
52. What are the two basic requirements for normal cells to divide that cancer cells ignore?
53. Compare density dependent inhibition to anchorage dependence.
54. How can one override density dependent inhibition in a tissue culture flask?
55. Explain how growth factors like human growth hormone works on the cellular level (chapter
11). Which checkpoint does hGH regulate?
- Describe the initial experiments that indicated there to be an intracellular signal regulating
mitotic cell division.
- Explain how cyclins and cdks regulate the cell cyclin.
- Explain how a growth factor can result in the passage of the G1 checkpoint via the activation of
transcription of cyclin D1.
- Describe MPF, how and when it is formed, and what it does.
56. Be able to explain how the cell cycle is regulated / controlled on the cellular level. Be sure to
include the three checkpoints, what each checkpoint “looks for” in general, whether the signals to
proceed are external/internal or both, etc… In terms of density dependent inhibition, how does
this relate to the G1 checkpoint? Explain how cells being next to each other can regulate G1.
57. What is cancer? How does cancer arise? Be very specific.
58. Explain why being born with a negative mutation in a gene that codes for a protein that
repairs your DNA can make you more susceptible to getting cancer.
59. Compare a malignant to a benign tumor.
60. What does the term “metastasis” mean and which type of tumor exhibits metastasis.
61. Explain how cancer spreads through the body and how new tumors arise.
62. Compare carcinomas, sarcomas, leukemia/lymphoma. Read this section in the book. Expect a
question.
63. Why is it so difficult to treat cancer compared to other diseases like those caused by bacteria?
64. Describe the current cancer treatments in detail. Know the examples and their sources.
65. Explain why deforestation is not good in terms of medicine / treating disease.
66. Make sure you understand the cell ploidy (haploid, diploid, triploid, etc…) and haploid
number.
67. Which chromosomes are in human gametes?
68. Draw a triploid cell with n=2.
69. Make sure you can follow the ploidy as well as the number of chromosomes as compare to
the amount of DNA through meiotic cell division. For example, after S phase, there are still 46
chromosomes (diploid), but twice as much DNA. In contrast, after meiosis I, there are 23
chromosomes (haploid), but the same amount of DNA as the starting somatic (parent) cell. There
will be questions pertaining to this.
1. Compare the chromosome number of a cell before going through meiosis and the cells after
meiosis. If a tetraploid cell goes through meiosis the four resulting cells will be…diploid.
2. What are the reasons organisms perform meiotic cell division. In animals we said it is to make
the gametes, but in plants and fungus…
3. Why is meiotic cell division also called reduction division?
4. Compare gametogenesis, spermatogenesis, oogenesis and meiotic cell division. Where does
each of these occur?
5. Mitotic cell division is also known as the cell cycle, while meiotic cell division is not. Explain.
6. Use the “finger method” of showing meiosis. Be sure to identify meiosis I and meiosis II and
the general purpose of each of these stages (What is being pulled apart in each?)
7. Explain why you are not surprised that meiotic cell division has mitotic cell division built into
it (meiotic division is just mitotic division with a few more levels of complexity added on).
8. Why pair up the homologous chromosomes? Why not pair them up randomly or not pair them
up at all? Same for the sisters, why not just replicate the DNA in S and let the sisters randomly
move around not attached by a centromere?
33. What is meant by an evolutionary trade-off? Give examples.
34. Why go through all the trouble of reproducing sexually? Explain how influenza of 1918, HIV
and Irish potato blight fit into this picture.
35. Explain why you are 1 in some ridiculous number of possible offspring that your parents
could have had.
36. Be able to calculate the number of possible gametes of any diploid organism regardless of
haploid number as well as the number of possible offspring between two such organisms (this is
excluding crossing over and mutation of course).
37. Explain in detail the four methods discussed that lead to genetic diversity in sexually
reproducing organisms. Which of these four is almost the sole means of genetic diversity in
asexual organisms. Which of these four is the creative process behind evolution in terms of
creating new genes resulting in new characteristics in organisms.
38. Describe precisely what alleles are. Give examples.
39. If I say that two genes are linked, what does that mean. How can genes be unlinked?
40. Explain in general how crossing over happens. What do the proteins/enzymes involved in this
process need to do?
41. Compare parental type chromosomes to recombinant chromosomes. How do recombinant
chromosomes form?
42. Describe how a human might end up with an abnormal number of chromosomes (We
discussed two general nondisjunctions. You should be able to draw these simple events).
43. Explain how we determine if a human whether born or unborn has an abnormal number of
chromosomes. How do we karyotype people? Why do we want to look at chromosomes in
metaphase as opposed to interphase or anaphase?
44. Describe how a centrifuge works.
45. What can a karyotype tell us?
46. Describe trisomy 21, trisomy 16, and the diseases resulting from nondisjunctions of sex
chromosomes.
47. Describe in detail how someone would end up with three number 21 chromosomes starting
from the somatic cells that will undergo meiotic cell division to conception of the human with
trisomy 21.
48. Describe the other mishaps that can happen during crossing over of meiosis like deletions,
etc…
49. Identify the three diseases caused by chromosomal deletions and describe each one.
50. What is so amazing about the dystrophin gene?
51. Explain why duplications are typically not as severe as deletions, and why duplications might
be very important in terms of evolution.
52. Explain why in order for the organisms to have any of these diseases like trisomy 21 or
muscular dystrophy, the chromosomal changes must be in the gametes. For example, I might end
up with trisomy 21 in one of my cell in the retina of my eye. Does this have or will it have
anything to do with Down Syndrome?
53. In terms of heredity, explain why I would not be too worried about my future children if I
were to accidently step into the X-ray laser at the lab and it hit me in the chest.
54. In order for offspring to be affected, changes in the chromosomes must happen in the gametes
or the cell that will form the gametes. Any other changes in any other cells in your body will do
nothing to your offspring. Make sure you understand this.
55. Study the powerpoints. Everything you need to know should be in there.
56. Make sure you can figure out all possible gametes of a given cell. Like if I said a diploid cell
with n=3, list all the possible gametes using numbers to differentiate each chromosome.
57. Make sure you understand the concept of independent orientation (you should know how
results in independent assortment at this point).