2011-2012
3rd Six Weeks Exam Study Guide
Use the diagram above to answer questions 1-4:
1. What process does this diagram represent?
Protein synthesis
2. Which number represents transcription?
Part 2
3. Which number represents translation?
Part 3
4. What is being made in part 4?
5. What are proteins made of?
Ribosomes
Amino Acids
6. Circle the correct answer:
Translation takes place in the
7. Describe translation.
nucleus / ribosome ?
Translating mRNA codons to amino acids
8. In protein synthesis, what happens after the DNA unwinds and unzips?
with complementary DNA bases to make mRNA strand
mRNA bases pair
9. How many bases make up a codon? How many bases does a nucleotide contain?
3
1
2011-2012
10. Below is an insertion mutation. How many amino acids would be added to this sequence as a
result of this mutation?
6 bases = 2 codons = 2 amino acids
Original strand
AUG GGG UGA
Mutated strand
AUG CCC CUG GGG UGA
2 codons inserted
11. What type of mutation is occurring in the chromosome below? If the chromosome below was
inherited by an offspring, how significant would the mutation be?
VERY significant because it affects many traits
4 sections deleted
12. Sickle cell anemia is a recessive disorder. If two heterozygous parents for the sickle cell anemia
gene have a child together, what is the probability of the child being heterozygous for this trait?
S
s
S
SS
Ss
s
Ss
ss
50% heterozygous
25% have the disorder
13. In fruit flies, the gene for eye color is carried on the X chromosome which is a sex chromosome
(sex-linked). The allele for red eyes is dominant over the allele for white eyes. If a white-eyed
(XrXr) female fruit fly is mated with a red-eyed (XRY) male, predict the possible offspring. How
many of the female offspring will be born with white eyes?
Xr
Xr
XR
XRXr
XRXr
Y
XrY
Females – 0% white
100% red
Males – 100% white
Xr Y
0% red
14. In humans, hemophilia is a sex linked recessive trait. Females can be normal, carriers, or have the
disease. Males will either have the disease or not (but they won’t ever be carriers).
XHXH female, normal
XHY male, normal
XHXh female, carrier
XhY male, hemophiliac
XhXh female, hemophiliac
If a female is a carrier and the male does not have the disorder, what is
the probability that their children will have the disease?
25%
XH
Xh
XH
XHXH
XHXh
Y
XHY
XhY
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15. What types of cells are produced by meiosis?
Gametes
16. What are gametes & what is their function?
Sex cells (sperm & egg cells) – Reproduction
17. Circle the correct answer:
Gametes are
diploid / haploid cells.
18. How many chromosomes do you get from each parent?
23
19. Why do polygenic traits such as eye color and hair color produce many variations?
They are controlled by many genes (polygenic)
20. Look at the picture to the right. Explain what
happened in layer E.
Environmental change
21. What is natural selection? Give an example.
Survival of the fittest
22. Circle the correct answer:
Populations / individuals
evolve.
23. The fossils to the right demonstrate the evolution of
the horse. The first one is from the modern horse.
Which do you think is the oldest fossil?
24. Why did the birds below develop different shaped
beaks?
Different available food resources
25. The formation of a river divides a species of frogs into
two groups. How will this affect the frogs?
Slowly become genetically different
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26. Which statement does not accurately describe natural selection?
A. Individual organisms change their genes to adapt to their environment.
B. The genetic composition of a population changes from one generation to the next.
C. More advantageous traits become more common in populations.
D. Beneficial and useful traits are inheritable.
27. In cats, the bones in the legs involved in walking are very similar to the bones in
whales’ flippers that are involved in swimming. Although they have different
functions, these bones, called homologous structures, lead us to the theory that cats and whales:
A. lived in the same time period
B. have a common ancestor
C. are both great swimmers
D. have analogous structures to begin with
28. Birds and reptiles have many similar structures. What is the best explanation for this?
They have a common ancestor
29. Using fossils scientists can determine what about living organisms?
Life has become more complex over time
30. What do scientists mostly use to make models of extinct organisms?
They examine fossils