1. During the transcription of a certain protein, an extra cytosine was placed into a gene region, throwing off the correct amino acid sequence. What type of mutation occurred?
A. Transposon
B. Insertion
C. Base-pair substitution
D. Deletion

2. DNA requires which of the following?
A. Sunlight C. Protein synthase
B. Meiotic division D. Many enzymes

3. Why is there no duplication of the DNA between meiosis I and meiosis II?
A. To produce genetically identical daughter cells
B. To increase genetic variability
C. To reduce the chromosome number to haploid in the resulting daughter cells
D. The chromosomes duplicate twice during meiosis I.

4. The genetic disorder sickle-cell anemia is an ex of
A. pleiotropy. C. epistasis.
B. heterozygous dominance. D. homozygous dominance.

5. What is the key difference between mitosis in plant cells and mitosis in animal cells?
A. The chromosomes aren't duplicated during interphase in plant cells.
B. Animal cell mitosis results in two daughter cells; plant mitosis produces three.
C. The two daughter cells formed in plant cell mitosis aren't genetically identical.
D. A cell plate is formed during mitosis in plant cells.

6. Which of the following genotypes causes Klinefelter syndrome?
A. XO C. XXY
B. XX D. XYY

7. In experiments with Drosophilia, _______ procedures have helped identify many gene functions.
A. pattern matching C. homeotic
B. knockout D. deleterious

8. When you notice that someone has unusually blue eyes, you've noticed their
A. phenotype. C. genotype.
B. allele. D. hybridization.

9. Why do researchers use DNA polymerase from a bacterium found in superheated water for PCR?
A. It's the only bacterium that contains this enzyme.
B. It can withstand the elevated temperatures that are required to unwind DNA.
C. DNA must go through high-temperature sterilization before PCA can occur.
D. These bacteria contain more DNA polymerase than any other species.

10. Why are there so many possible combinations of maternal and paternal traits in each generation of offspring?
A. Because there are the same number of chromosomes in each cell
B. Because of the random grabbing of chromosomes by the microtubules during metaphase I
C. Because of the biological components that chromosomes are made of
D. Because of the high frequency of viral invasion

11. Which of the following most contributes to a large variation of traits inherited by an offspring?
A. Production of polar bodies
B. A small gene pool
C. Homozygous dominance
D. Random shuffling of homologous chromosomes in gamete production

12. Which of the following strands of DNA would be the complement strand to C-C-A-T-C-G?
A. G-G-T-A-G-C C. A-A-C-G-A-T
B. G-G-A-T-G-C D. T-T-G-C-T-A

13. Why are there more males with color blindness than females?
A. The gene for color blindness is found on the Y chromosome.
B. The recessive gene is usually masked by another X chromosome in females.
C. Color blindness is an X-linked dominant trait.
D. All the sons of an affected male will have the disorder.

14. Which of the following would have the same base sequencing in their DNA?
A. A male parent and his male offspring
B. Siblings
C. Identical twins
D. A female parent and her offspring

15. Mitotic division produces two daughter cells with a _______ number of chromosomes, while meiosis produces four daughter cells with a _______ number of chromosomes.
A. haploid, diploid C. diploid, haploid
B. haploid, haploid D. diploid, diploid

16. A recessive allele t is responsible for a condition called distonia. A man who has this condition marries a woman who doesn't. One of their four children has the condition. What are the possible genotypes of the man and woman?
A. The father is Tt; the mother is TT. C. Both parents are tt.
B. The father is tt; the mother is TT. D. The father is tt; the mother is Tt.

17. Suppose a cell's membrane becomes more permeable than usual and loses some of its proteins. If the cytoskeleton shrinks and becomes disorganized, the cell is probably
A. cancerous.
B. ready to begin mitosis.
C. being engulfed by a phagocyte.
D. shutting down one of its X chromosomes as dosage compensation.

18. During meiosis, the chromatids become daughter chromosomes during which stage?
A. Prophase I C. Anaphase II
B. Metaphase II D. Telophase I

19. If you wanted to produce a certain protein in the laboratory, which of the following would be necessary for establishing the correct amino acid sequence?
A. Ribosomal proteins C. rRNA
B. mRNA D. Anticodons

20. The offspring of two parents that are heterozygous for a given trait have a _______ percent chance of being homozygous for that trait.
A. 0 C. 50
B. 25 D. 100

21. If a piece of DNA breaks off a chromosome and attaches itself to a nonhomologous chromosome at another location, what type of change has occurred?
A. Translocation C. Deletion
B. Duplication D. Inversion