Download Bio 309F

-1Bio 309F
Exam #2
March 28, 2006
Name_____________________________________
Note: please place your name and answers on the scantron. We will only grade the scantron so double
check to be sure the answers on the scantron are as you want them. Through out the exam, please cover
your answers with the sheet of paper provided. Do not use electronic gadgets, including telephone--so,
please turn off your telephone prior to starting the exam.
I. Multiple Choice (50 questions, 2 points each for a total of 100 points). Circle the best answer.
1. The absence of a Y chromosome in an early embryo causes the:
A. embryonic testis to become an ovary
B. Wolffian duct system to develop
C. Mullerian duct system to degenerate
D. indifferent gonad to become an ovary
E. indifferent gonad to become a testis
2. What is the phenotype of an individual with a non-functional (mutation) SRY gene?
A. female
B. male
C. hermaphrodite
D. pseudohermaphrodite
3. What is the phenotype of an individual with a normal SRY gene but a non-functional AZF gene?
A. female
B. male
C. hermaphrodite
D. pseudohermaphrodite
4. There are normal males with XX karyotypes and normal females with XY karyotypes. Which of the
following best describes these conditions?
A. One of the X chromosomes in the male has picked up the SRY gene from the Y chromosome via
recombination or translocation.
B. The Y chromosome in the female has lost the SRY gene via deletion or mutation
C. Its all in the hormones, has nothing to do with SRY. XX males have high levels of testosterone and
XY females have high levels of estrogen.
D. A and B are correct
E. A, B, and C are correct
5. A couple who are non-bald have a son who is bald? What are the genotypes of the parents?
Female
Male
A.
BB
BB
B.
Bb
Bb
C.
Bb
bb
D.
bb
Bb
E.
bb
bb
6. Pattern baldness is described as a:
A. sex-linked dominant trait
B. sex-linked recessive trait
C. sex-influenced trait
D. sex-limited trait
E. none of the above
-27. A woman was found to have a mosaic disorder called anhidrotic ectodermal dysplasia where patches
of skin have either sweat glands or no sweat glands. How would one account for this?
A. X-inactivation
B. autosomal recessive trait
C. autosomal dominant trait
D. A, B,and C could account for the mosaic disorder
E. None of the above
8. An early embryo made up of about 100 cells is called a:
A. trophoblast
B. embryoblast
C. fetalblast
D. blastocyst
E. none of the above
9. The genetic code of life is composed of 4 nucleotides (G:C:A:T). A single codon is composed of
_______nucleotides
A. 1
D. 4
B. 2
E. 6
C. 3
10. An anticodon is found on
A. mRNA
B. tRNA
C. rRNA
D. DNA
E. None of the above
11. Which of the following is/are start codon(s)?
A GUC
B AUG
C CCA
D CAG
E AGC
12. Which of the following is/are stop or termination codons?
A. UAC
B. UGA
C. UAA
D. UAG
E. B, C and D are correct
13. Beta hemoglobin chain has 143 amino acids. How many nucleotides are involved in coding for the
beta hemoglobin chain?
A. 143
B. 286
C. 429
D. 572
E. 715
-314. DNA replication occurs during ____ phase of the cell cycle.
A. GO
D. G2
B. G1
E. M
C. S
15. Enzyme that forms a new DNA chain using single-stranded DNA as a template
A. RNA polymerase
D. Reverse transcriptase
B. DNA polymerase
E. None of the above
C. DNA ligase
16. Enzyme that covalently links DNA strands together
A. DNA polymerase
D. DNA ligase
B. Helicase
E. None of the above
C. Primase
17. A gene has 6 exons and 5 introns. Exon 1 has 12 nucleotides, exon 2 has 21 nucleotides, exon three
has 15 nucleotides, exon four has 5 nucleotides, exon five has 22 nucleotides, exon six has 21
nucleotides intron 1 has 30 nucleotides, intron 2 has 15 nucleotides, intron 3 has 12 nucleotides,intron 4
has 15 nucleotides and intron 5 has 17 nucleotides. This gene will code for a protein that has
__________ amino acids.
A. 12
B. 18
C. 27
D. 32
E. 62
18. During transcription, the following RNA(s) will be involved in the process
A. ribosomal RNA
B. transfer RNA
C. message RNA
D. B and C are correct
E. A, B, and C are correct
19. The size of a gene is defined by
A. start codon
B. stop codon
C. Introns
D. A and B
E. A, B, and C are correct
20. Biological functions of proteins/polypeptides (mechanism whereby the genetic information of a
gene is carried out by proteins) are determined by
A. number of amino acids
B. ratio of specific amino acids
C. sequence of amino acids
D. secondary structure of peptide chain
E. none of the above
21. Choose the molecular definition of a gene that includes all of DNA elements that may be part of the
DNA sequence of a gene:
A. The DNA sequence of a gene includes only exons.
B. The DNA sequence of a gene includes only exons and introns.
C. The DNA sequence of a gene includes exons, introns and noncoding regulatory control regions.
D. The DNA sequence of a gene includes exons and noncoding regulatory control regions
-422. The Central Dogma of genetic information transfer was proposed by Sir Francis Crick in 1957. It
has undergone a few changes over the years but is still very similar to Crick's original idea. Crick
considered the crucial point in his hypothesis to be the idea that information transfer is not allowed in
which one of the following conditions?
A. Transfer from DNA to RNA.
B. Transfer from RNA back to DNA.
C. Transfer from RNA to protein.
D. Transfer from protein back to RNA.
23. Microbiologist who demonstrated that DNA was the genetic material.
A. Oswald Avery
B. Herbert Boyer
C. Rosalind Franklin
D. Barbara McClintock
E. James Watson
24. Regions of genes that do not code for a protein are called
A Primers
B introns
C okazaki fragments
D. exon
25. RNA polymerase uses --------- as a template to synthesize --------A RNA, protein
B RNA, DNA
C DNA, RNA
D DNA, protein
E. protein, DNA
26. The information carried by DNA is used as a template to produce a _____which then moves to the
ribosome for protein synthesis
A tRNA
B rRNA
C double stranded RNA
D mRNA
E. single stranded DNA
27. A permanent alteration in the DNA of an organism is called:
A mutation
B hereditary marker
C replicon
D allele
E. anticodon
28. mRNA:
A. contains ribose sugar
B is found only in prokaryotes
C contains uracil instead of thymine
D is synthesized using the enzyme ligase
E. A and C are correct
29. In DNA, the base adenine always pairs with what other base
A guanine
C. thymine
B cytosine
D. adenine
-530. Spontaneous mutations
A are caused by chemical mutagens
B are caused by physical agents such as ultraviolet light or x-rays
C are the result of errors in the base pairing of nucleotides during replication
D occur at a rate higher than the rate of induced mutations
31. A frameshift mutation occurs when
A an adenine is inserted into the DNA sequence of an organism
B a thymine replaces a guanine in the DNA sequence of an organism
C three new bases are inserted into the DNA strand
D three bases are deleted from the DNA strand
32. Mutation in the hemoglobin beta chain resulting in sickle cell anemia is called:
A. missense
B. sense
C. nonsense
D. frameshift
E. trinucleotide repeats
33. Mutation causing Fragile X Syndrome is called:
A. missense
B. sense
C. nonsense
D. frameshift
E. trinucleotide repeats
34. _____, former UT Professor, demonstrated that x-irradiation caused mutations.
A. H. J. Muller
B. T. H. Morgan
C. F. Griffith
D. Rosalind Franklin
E. Lineus Pauling
35. Ultra violet light (UBV) induces ______dimers in DNA. Defect in DNA repair gene results in skin
cancer called xeroderma pigmentosum.
A. uracil dimers
B. adenine dimers
C. cytosine dimers
D. thymine dimers
36. Which of the following is/are known chemical mutagens?
A. aspartame
B. caffeine
C. aflatoxin B
D. benzo(A)pyrene
E. C and D are correct
37. The Ames test is used to determine if a chemical:
A increases the rate at which a bacterial cell divides
B decreases the number of cells in a culture
C induces mutations in a cell's DNA
D decreases the ability of a cell to photosynthesize
-638. A major problem with the Ames test is that it does not evaluate:
A. chemicals with ring structures as potential mutagens
B. chemicals from plants as potential mutagens
C. metabolites of chemicals as potential mutagens
D. A and B are correct
E. A, B, and C are correct
39. A protein derived from a gene with as sense mutation would:
A. have no effect on the size of the resulting protein
B. resulting protein would contain fewer number of amino acids
C. resulting protein would contain greater number of amino acids
D. resulting protein would have an amino acid substitution
E. none of the above
40. Characteristics of metabolic diseases in newborn include:
A. severe vomiting
B. odor of breath, skin or urine
C. seizures
D. poor muscle coordination
E. All of the above
41. Phenylketonuria (PKU) is an autosomal recessive trait where amino acid ____ is not converted to
amino acid _____.
A. valine, isovaline
B. methionine, leucine
C. phenylalanine, leucine
D. phenylalanine, tyrosine
E. phenylalanine, methionine
42. A PKU child at birth would be expected to have elevated levels of:
A. valine
B. isovaline
C. methionine
D. phenylalanine
E. tyrosine
43. A PKU female who received nutritional intervention starting at birth to 10-11 years of age, reducing
adverse effects becomes pregnant at the age of 21. Her husband is homozygous normal for this trait.
A. the expected child is not expected to express the PKU trait, therefore, no need for special diet during
pregnancy.
B. the expected child is not expected to express the PKU trait; however, a special diet during pregnancy
is needed.
C. When born, special diet is needed during nursing (mother's milk)
D. Special diet for child is needed after nursing stops
E. B and C are correct
44. Proteins derived from genes coding for metabolic pathways are called:
A. structural proteins
B. transfer proteins
C. functional proteins
D. enzymes
E. transcription factors
-745. Gastric distress in an adult due to drinking milk can occur in the absence or reduced levels of:
A. lactase needed to convert the disaccharide sugar lactose into monosaccharides
B. galactase needed to convert the disaccharide sugar maltose into monosacchrides
C. sucrase needed to convert the disaccharide sugar sucrose into monosacchrides
D. sugar fructose
E. none of the above
46. Enzymes have all of the following characteristics, except:
A. they act as biological catalysts
B. they are proteins
C. they carry out random chemical reactions
D. they convert substrates into proteins
E. when mutated they can cause genetic disease
47. A newborn is normal at birth but develops gastric distress when first given solid food (fruits and
vegetables). The child most likely has as metabolic defect called:
A. galactosemia
B. Tay Sachs
C. Hereditary fructose intolerance
D. maple sugar urine disease
E. Lesch-Nyhan syndrome
48. Which of the following researchers made contributions to our understanding of metabolic disorders?
A. Archibald Garrod
B. George Beadle
C. Edward Tatum
D. B and C are correct
E. A, B, and C are correct
49. Teratogens:
A. a substance that causes missense mutations
B. a substance that causes frame shift mutations
C. a substance that causes a birth defect
D. A and C are correct
E. B and C are correct
50. Which of the following can be described as teratogens?
A. Exposure of embryo/fetus to irradiation
B. vitamin A during first three months of embryonic/fetal development
C. alcohol
D. german measles
E. all of the above