Download Mid-Term Exam 3a - Buffalo State College Faculty and Staff Web

STATE UNIVERSITY COLLEGE AT BUFFALO
Department of Biology
Biology 100
Principles of Biology
Spring 2004
Dr. Wadsworth
Mid-Term Exam 3a
Genes and Biotechnology
Cover Sheet
Name: ____________________________________________________
(Print)
Instructions.
1. Print your name in the space designated on this cover sheet.
2. Be sure that your exam has 9 pages including this cover sheet.
3. Read each question carefully and answer in the space provide
4. At the end of the exam there are 6 short answer questions. Answer only 5 of
these 6 questions. Answering all six questions may reduce your grade.
Under the question you choose not to answer, please write the word "Skip".
Failure to write "SKIP" under the one question you choose not to answer will
reduce your grade.
Multiple Choice
Choose the best answer for the question or the best ending for each statement. Write the letter
(A-E) which corresponds to the best answer on the line before the question. (2 pts each)
____1. Which of the following sentences best describes the relationship between histones and
chromosomes?
A.
B.
C.
D.
E.
Histones are the amino acids that compose the DNA of chromosomes.
Histones make up the centromere of chromosomes.
DNA is wrapped around histones to make up chromosomes.
DNA gets its dcolor from darkly pigmented histones.
Histones replicate the DNA during S-Phase of the cell cycle.
_____ 2. Suppose that a nucleus of a frog liver cell contained 50 chromosomes. How many chromosomes
would you expect in the nuclei after M-phase of the cell cycle?
A.
B.
C.
D.
E.
100
50
25
100 sister chromatids
200 sister chromatids
_____ 3. How many autosomes would you expect to find in a human skin cell?
A.
B.
C.
D.
E.
44
48
46
2
4
_____ 4. Mitosis is important in cell division because it:
A.
B.
C.
D.
E.
produces both somatic cells and gametes in humans.
generates aneuploids, providing variation in the offspring.
ensures proper gene expression in offspring.
replicates the DNA before cell division .
ensures that daughter cells receive a complete set of chromosomes.
_____ 5. A man and woman with type B blood get married. The woman has a son with type O blood.
Which of the following would a genetic consular likely tell the husband.
A. Both the man and the woman are heterozygous for the ABO blood type gene.
B. Because the O allele is sex linked it is expressed in the son.
C. The man isn’t the father of the child since its blood type didn’t match either of the
parents.
D. There had to be a mixup at the hospital, because this child blood type doesn’t match
either parents.
E. The child is an extraterrestrial being with green blood.
_____ 6.In dogs, a single gene controls ear floppiness. The allele for erect ears is dominant and the allele
for floppy ears is recessive. If I breed a true-bred german shepherd (erect ears) with a true-bred
Labrador retriever (floppy ears) what is the probability that the first pup will have erect ears?
A.
B.
C.
D.
E.
0%
25%
50%
75%
100%
_____ 7. In peas, the allele for round seeds (R) is dominant to the allele for wrinkled seeds (r). If a
heterozygous plant were bred with a homozygous recessive plant, what proportion of the offspring
would have round seeds.
A.
B.
C.
D.
E.
0%
25%
50%
75%
100%
_____8. In chickens there is a gene called “frizzled”. The gene gets this name because the recessive allele
causes abnormal feathers. However, the frizzled gene also affects the body temperature of the
bird as well as the structure of some internal organs. This characteristic of frizzle affecting
several different traits is an example of which of the following.
A.
B.
C.
D.
E.
Codominance
Polygenic
Pleiotropy
Partial Dominance
Segregation
_____9. A healthy couple has a child with cystic fibrosis. Remember that cystic fibrosis is a recessive
human trait. What is the probability that their next child will have cystic fibrosis?
A.
B.
C.
D.
E.
0%
25%
50%
75%
100%
_____10. Hemophilia is an example of a sex-linked trait. A hemophiliac man will pass the alleles for this
trait to:
A.
B.
C.
D.
E.
only his sons
only his daughters
all of his children
none of his children
every other son
_____11. In Mendel’s time, most people believed that:
A.
B.
C.
D.
E.
all genetic traits bred true.
only certain forms of domesticated plants and animals bred true.
the characteristics of parents were blended in the offspring.
genes were always dominant
the inheritance of traits was controlled by blood.
_____ 12. All the offspring of a white hen and black rooster are grey. This is probably an example of
which of the following?
A.
B.
C.
D.
E.
Codominance
Lethality
Pleiotropy
Incomplete Dominance
Segregation
_____ 13. In class we discussed the inheritance of hypercholesterolemia as an example of a gene with
incomplete dominance. If two people with hypercholesterolemia have children, what is the
probability that their children will also have hypercholesterolemia?
A.
B.
C.
D.
E.
0%
25%
50%
75%
100%
_____ 14. Which of the following best describes the role of the sex reversal Y (sry) gene in humans.
A.
B.
C.
D.
E.
It reverses the sex of any individual that carries it.
It causes hermaphrodism in humans
There are two copies of it in females and one copy in males
It is found in all sperm
Individuals with sry develop a male phenotype.
_____ 15. A woman heterozygous for color blindness (an X-linked recessive allele) marries a man with
normal color vision. What is the probability that their first child will be color blind?
A.
B.
C.
D.
E.
0%
25%
50%
75%
100%
_____ 16. If a segment of DNA is 5’ – CATTAC – 3’, then the complementary strand would be:
A.
B.
C.
D.
E.
3’ – CATTAC – 5’
5’ – CATTAC – 3’
3’ – GTAATG – 5’
5’ – GTAATG – 3’
5’ – CATTAC – 5’
_____17. Rank the following nucleic acid structures from largest to smallest.
A.
B.
C.
D.
E.
Chromosome, Gene, Open Reading Frame, Codon
Genes, Chromosome, Open Reading Frame, Codon
Codon, Genes, Chromosome, Open Reading Frame
Chromosome, Codon , Gene, Open Reading Frame
Codon, Chromosome, Open Reading Frame, Genes
_____ 18. If two nitrogenous bases from DNA are described as complementary, then they:
A.
B.
C.
D.
E.
would hydrogen bond with each other
would be involved in protein synthesis
would be found in the cytosol
would be attached to ribosomes
would be found in mRNA
_____ 19.The enzyme, RNA polymerase, binds to which of the following components of a gene?
A.
B.
C.
D.
E.
Start Codon
Stop Codon
Promoter
The first slot of the ribosome
The dominant allele
_____20. Which of the following is not a difference between RNA and DNA
A.
B.
C.
D.
RNA is single stranded and DNA is double stranded
RNA uses Uracil (U) and DNA uses Thymine (T)
RNA is in prokaryotes and DNA is in eukaryotes
RNA has ribose and DNA has deoxyribose
_____21. Which of the following carries amino acids to ribosomes, and is considered the "adaptor"
molecule between codons and amino acids?
A.
B.
C.
D.
E.
mRNA
tRNA
hnRNA
rRNA
all of these
_____22. Which of the following is not considered to be a significant risk of BT corn?
A.
B.
C.
D.
E.
It is killing Monarch Butterflies
Some people may be allergic to it
The cry1a gene may spread to other species
It promotes the use of monocultures
None of these are significant risk
_____ 23. Which of the following explains why golden rice is being introduced to developing nations.
A.
B.
C.
D.
E.
It is resistant to rice fungus which destroys rice crops in tropical regions.
It will generate a rice product that can be exported and provide a cash crop for farmers.
It provides a source of vitamin A to the diet in developing countries
It is resistant to insects, so farmers in developing nations do not need to use pesticides
It can be cultivated with other crops, providing farmers with more food per acre.
_____ 24. Which of the following is not part of translational elongation?
A.
B.
C.
D.
E.
The ribosome rachets over one codon
The ribosome accepts a new tRNA
The ribosome expels the used tRNA
The ribosome catalyzes the synthesis of a new peptide bond
The ribosome releases the new polypeptide chain
_____ 25. Which of the following best describes why DNA replication is called semi-conservative?
A. Replication of DNA in the nucleus is catalyzed by two different enzymes, RNA
polymerase and DNA polymerase
B. Only deoxynucleotides are used during DNA replication
C. A equal mixture of deoxynucleotides and ribonucleotides are used during replication of
DNA.
D. After replication the DNA molecules are composed of one new strand and one old strand.
E. The DNA is only replicated between start and stop codons.
Short Answer Questions
Answer only five of the following six questions in the space below each question. Under
the one question you choose not to answer, write the word "SKIP".
26. Pseudohypertorphic muschular dystrophy is a disorder that causes gradual deterioration of the muscles.
It is only seen in boys born to apparently normal parents and usually results in premature death in
the early teens. Is this disorder caused by a dominant or recessive allele. Explain your reasoning.
27. Explain the difference between reproductive cloning and therapeutic cloning.
28. Explain why a non-sense mutation will usually have a bigger impact on phenotype than a mis-sense
mutation.
29. Studies of human aneuploids have demonstrated that it is not the number of X chromosomes that is
important for sex determination but it is the presence or absence of a Y chromosome. Describe
how Klinefelter's Syndrome demonstrates this principle. How would the phenotype of this type of
aneuploid been different if the Y chromosome was irrelevant to sex determination but instead the
number of X chromosomes was important.
30. Explain why the substrate specificity of enzymes were important in Avery’s experiment that proved
genes were made of DNA.
31. The sequence of a very short mRNA is written below. How many amino acids will the polypeptide
encoded by this mRNA have and what is the sequence of amino acids in the polypeptide?
GUAGGACCUAGAUGACUGUAUUUGGCUAACCUGUAGUAGU