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General Biology
Spring 2010
Name
Exam 2
MULTIPLE CHOICE QUESTIONS. Select the ONE choice that BEST answers the question. Write the letter of your answer
in the space provided. Please feel free to ask me to clarify any question. (2 points each, 70 total)
____1. The creation of offspring carrying genetic information from two parents is called
A. asexual reproduction
B. regeneration
C. a life cycle
E. C and D are correct
D. sexual reproduction
____2. In many organisms, including humans, chromosomes are found in homologous pairs. Homologous chromosomes _____.
A. are identical both in the arrangement of their genes and in every version of every gene
B. are identical in the arrangement of their genes, but some versions of the genes may differ between the chromosomes
C. have some similar arrangements of their genes, but some versions of the genes may differ between the chromosomes
D. are similar in size and shape, but this similarity has nothing to do with placement of gene arrangement or type
____3. If a grasshopper sperm cell contains 12 chromosomes, a grasshopper egg cell would contain _____ chromosomes.
A. 6
B. 12
C. 24
D. 0
E. None are correct
____4. Which of the following correctly describes the timing of DNA synthesis?
A. DNA is synthesized continuously
B. DNA is synthesized in G2 of interphase immediately preceding mitosis
C. DNA is synthesized during the S phase of interphase
D. DNA is synthesized only during mitosis
____5. Within one chromosome, what is the relationship between the sequence of bases in DNA of one sister chromatid
compared to the other?
A. the sequences are identical
B. the sequence in one chromatid is complementary to the sequence in the other
C. the sequences are similar, but not identical
D. the sequences are unrelated
____6. During which phase of mitosis do the chromosomes line up on a plane located equidistant from the two spindle poles?
A. interphase
B. prophase
C. metaphase
D. anaphase
E. telophase
____7. Which of the following is not a function of mitosis in humans?
A. production of gametes from diploid cells
B. multiplication of somatic cells
D. replacement of lost or damaged cells
E. growth
____8. In meiosis, separation of homologs occurs in _________.
A. prophase II
B. anaphase I
C. metaphase I
____9. Meiosis _____________.
A. halves the number of chromosomes
C. produces diploid cells
D. anaphase II
C. repair of wounds
E. metaphase II
B. is responsible for body growth
D. follows mitosis and splits the cytoplasm in two
____10. What is the typical result when a diploid cell undergoes meiosis?
A. two haploid cells
B. two diploid cells
C. four diploid cells
E. two haploid cells and two diploid cells
____11. During telophase I _____.
A. homologues separate and migrate toward opposite poles
C. sister chromatids separate and migrate toward opposite poles
E. the cell is haploid
D. four haploid cells
B. chromosomes line up in one plane
D. nuclei re-form
____12. During which stage of meiosis do synapsis and the formation of tetrads occur?
A. interphase
B. prophase I
C. metaphase I
D. prophase II
E. None are correct
____13. Which of the following does not lead to genetic variability?
A. random fertilization B. crossing over during meiosis C. division of chromosomes during anaphase of mitosis
D. orientation of chromosomes during metaphase I of meiosis
E. mutation
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____14. Down syndrome can be the result of _____.
A. nondisjunction of chromosome 21
B. meiosis without cytokinesis
D. an extra cycle of DNA synthesis during the S phase
____15. Which of the following carry the same genetic information?
A. sister chromatids
B. X and Y chromosomes
D. homologous chromosomes
E. A and C are correct
C. a deletion in chromosome 21
E. All are correct
C. daughter cells resulting from mitosis
____16. Assume tall (T) is dominant to dwarf (t). If a homozygous dominant individual is crossed with a homozygous dwarf, the
offspring will ___________.
A. all be intermediate in height
B. all be tall
C. be ½ tall and ½ dwarf
D. be ¾ tall and ¼ dwarf
E. all be short
____17. Edward was found to be heterozygous (Ss) for sickle-cell anemia. The alleles represented by the letters S and s are
A. on the X and Y chromosomes.
B. linked.
C. on homologous chromosomes.
D. both present in each of Edward’s sperm cells.
E. on the same chromosome but far apart.
____18. Cystic fibrosis is an autosomal recessive disorder. Using C and c to represent the alleles, what is the genotype of a carrier
of cystic fibrosis?
A. CC
B. Cc
C. cc
D. Cc or cc
E. A and C are correct
____19. Two individuals decide to have children. The expected blood group genotypes are 50% of blood type A, and 25% each of
blood types AB and B. What genotypes are the parents?
A. IAi x IBi
B. IAi x IAIB
C. IAi x ii
D. IBi x IAIB
B
E. I i x ii
____20. What is the normal complement of sex chromosomes in a human female?
A. two X chromosomes
B. two Y chromosomes
C. two X chromosomes and one Y chromosome
D. one X chromosome and one Y chromosome
E. one Y chromosome
____21. A woman who is heterozygous for hemophilia and a non-hemophiliac man have a normal son. What is the chance that
their next son will be a carrier?
A. 0%
B. 25%
C. 50%
D. 75%
E. 100%
____22. Which of the following is NOT true about double-stranded DNA?
A. It is helical
B. It contains hydrogen bonds
C. The two strands are said to be complimentary
D. Adenine and uracil are present in equal amounts
E. The strands run in opposite directions
____23. During the replication of DNA molecules _________.
A. both strands of the molecule act as templates
B. the reaction is catalyzed by RNA polymerase
C. errors never occur
D. only one strand acts as a template
E. the cell undergoes mitosis
____24. Experiments have demonstrated that the "words" of the genetic code (the units that specify amino acids) are
A. nucleotide sequences of various lengths
B. two-nucleotide sequences
C. enzymes
D. single nucleotides
E. three-nucleotide sequences
_____.
____25. Which of the following are correctly arranged by size, from smallest to largest?
A. chromosome - gene - codon - nucleotide
B. nucleotide - gene - chromosome - codon
C. codon - nucleotide - chromosome - gene
D. chromosome - gene - nucleotide - codon
E. nucleotide - codon - gene - chromosome
____26. What amount of thymine would be found in a strand of DNA composed of 15% cytosine?
A. 15%
B. 30%
C. 35%
D. 70%
____27. Which one of the following sequences best describes the flow of information when a gene directs the synthesis of a
cellular component?
A. RNA → DNA → RNA → protein
B. DNA → RNA → protein
C. protein → RNA → DNA
D. DNA → amino acid → RNA → protein
E. DNA → tRNA → mRNA → protein
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____28. What would be the anticodon for the DNA sequence CTC?
A. GAG
B. CUC
C. AUG
D. CTC
E. GUG
____29. Much of genetic engineering uses plasmids, which are _____.
A. repeating sequences that protect DNA from digestion when it is inserted into a foreign cell
B. small circlets of DNA found in bacteria
C. infectious proteins
D. segments of RNA that must be attached to DNA before the DNA can replicate
E. ends of cut DNA molecules that are "sticky" because they have unpaired base sequences
____30. Ligase enzymes ____.
A. edit proteins
D. bind together strands of DNA
B. cut DNA at specific sites
E. bind RNA fragments together
C. stop transcription
____31. When a typical restriction enzyme cuts a DNA molecule, the cuts are staggered so that the DNA fragments have singlestranded ends. This is important in recombinant DNA work because _____.
A. it allows a cell to recognize fragments produced by the enzyme
B. the single-stranded ends serve as starting points for DNA replication
C. the fragments will bond to other fragments with complementary single-stranded ends
D. only single-stranded DNA segments can code for proteins
____32. DNA profiling used as evidence in a murder trial look something like supermarket bar codes. The pattern of bars in a
DNA profile shows _____.
A. the exact location of a specific gene in a genomic library
B. the presence of dominant or recessive alleles for particular traits
C. the presence of various-size fragments of DNA
D. the order of bases in a particular gene
E. the order of genes along particular chromosomes
____33. Gel electrophoresis separates DNA molecules on the basis of size. Which of the following would move the slowest?
A. pBr322 (4.39 kb)
B. F plasmid (100 kb)
C. lambda phage (49 kb)
D. pUC18 (2.69 kb)
____34. Concerns have been raised as to the safety of genetically modified organisms (GMOs). Which of the following would be
a concern when modifying a plant to be resistant to a broad-spectrum herbicide?
A. an increased shelf life of the fruit from the plants
B. a decrease in the use of herbicides
C. the production of herbicide-resistant weeds
D. a decrease in food production
E. All are correct
____35. Gene therapy involves _____.
A. replacing organs affected with genetic disorders by transplants
B. allowing individuals to follow the natural progression of a genetic disorder, accompanied by psychological
counseling, then treating with drugs only when the condition becomes life-threatening
C. no serious ethical questions
D. adding a functioning version of the defective gene to the cells of an individual
E. All are correct
TRUE/FALSE. Write T for TRUE statements and F for FALSE statements in the space provided. (2 points each, 30 total)
____ 36. A karyotype is an ordered arrangement of images of a cell’s chromosomes.
____ 37. DNA replication occurs during the early phases of mitosis.
____ 38. Bacteria cells divide by the process of mitosis.
____ 39. In metaphase I, all chromosomes line up individually at the metaphase plate.
____ 40. Humans have 44 autosomal chromosomes.
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____ 41. Crossing over is the process where non-identical sister chromatids exchange pieces.
____ 42. Gregor Mendel was the Austrian monk who used pea plants to establish the patterns of inheritance.
____ 43. When stained, homologous chromosomes have the same banding patterns.
____ 44. An allele that is fully expressed is referred to as dominant.
____ 45. In a bacteria cell, transcription takes place in the nucleus.
____ 46. One of tRNA’s functions is helping to translate codons into amino acids.
____ 47. Mutations are chemical changes in the genetic material.
____ 48. Ligase enzymes produce "sticky ends" of DNA because they have unpaired base sequences.
____ 49. Golden rice is genetically modified to contain more fiber and more protein than regular rice.
____ 50. A DNA fingerprint is the sequence of DNA nucleotides from the chromosomes of an individual.
EXTRA CREDIT. Answer the questions in the space provided. (2 points each)
1. A) Draw a cell with 4 chromosomes in any phase of mitosis (naming the stage) AND B) label at least 2 different structures
other than the chromosomes.
2. A) Define the terms genotype and phenotype. B) How are these two terms related to each other?
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