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Unit 3 – Our Cells at Work
Pre/Post Test A
1. A mutation that involves one or a few nucleotides is called
a. a point mutation
c. a translocation
b. an inversion
d. a mutagen
2. Your traits and how your cells function are the results of
a. the environment
c. mutations
b. carbohydrates built from information in genes d. proteins built from information in genes
3. Unlike DNA, RNA contains
a. adenine
b. uracil
c. phosphate groups
d. thymine
4. How many nucleotides in mRNA are needed to specify one amino acid?
a. 12
c. 3
b. 9
d. 6
5. Which is the correct sequence of the transfer of information in most organisms?
a. protein to DNA to RNA
c. DNA to RNA to protein
b. RNA to DNA to protein
d. RNA to protein to DNA
6. Crossing a purebred purple-flowered plant with a purebred white-flowered plant can be symbolized
by which of the following genotypic crosses?
a. Ff x ff
c. FF x FF
b. Ff x Ff
d. FF x ff
7. After fertilization, an organisms grows (creates more cells) through the process of
a. mitosis
c. cellular respiration
b. meiosis
d. genetic engineering
8. In rabbits, the allele for black coat color (B) is dominant over the allele for brown coat color (b).
Two black rabbits (Bb) mate. What can you predict about the offspring?
a. Most of the offspring will be brown
c. Most of the offspring will be black
b. All of the offspring will be black
d. All of the offspring will be brown
9. In eukaryotes, the copying of a gene by mRNA (transcription) takes place in the
a. nucleus
c. membrane
b. cytoplasm
d. endoplasmic reticulum
10. If a pea plant’s alleles for height are tt, what is true of its parents?
a. both parents contributed a dominant allele
c. both parents were short
b. both parents contributed a recessive allele
d. codominance
11. During normal mitotic cell division (mitosis), a parent cell that has four chromosomes will produce
two daughter cells, each containing
a. two chromosomes
c. eight chromosomes
b. four chromosomes
d. sixteen chromosomes
12. Genes are segments of DNA that are the instructions for building
a. DNA
c. lipid bilayers
b. proteins
d. amino acids
13. Organisms that have two identical alleles for a particular trait are said to be
a. hybrid
c. heterozygous
b. dominant
d. homozygous
14. At the end of meiosis, there are
a. two haploid daughter cells
b. four haploid daughter cells
c. two diploid daughter cells
d. four diploid daughter cells
15. Roan cattle show codominance for the color of their hair. There are alleles for red hair and alleles
for white hair. What would you expect a heterozygous roan bull to look like if the trait showed
incomplete dominance?
a. It would be red
c. it would be pink
b. It would be white
d. it would be spotted
16. Why does DNA replication occur?
a. To add more traits to a living organism as it ages
b. To fill increased space within the nucleus of a growing cell
c. To change the traits of a living organism to meet its needs in a new environment
d. To provide new cells with a complete and identical copy of genetic material
17. If one side of the DNA molecule reads ATGCCGT, what would the complementary side read?
a. TACGCCU
c. UACGGCA
b. TACGGCA
d. TAGCCGA
18. The farther apart two genes are located on a chromosome, the
a. less likely they are to assort independently
b. more likely they are to be linked
c. less likely they are to be inherited together
d. less likely they are to be separated by crossing over
19. The arctic fox is blue-gray in the summer and white in the winter. What most likely influences this
change?
a. genes and the environment
c. the environment alone
b. dominant alleles
d. codominant alleles
20. What are different versions of a gene for the same trait called?
a. phenotypes
c. purebreds
b. alleles
d. homozygous
21. Which of the following describes a phenotype?
a. Gg
b. homozygous
c. having freckles
d. heterozygous
22. Which of the following is an organism in which two alleles for a trait are different?
a. heterozygous
c. dominant
b. homozygous
d. recessive
23. During what phase of mitosis do the chromosomes line up along the middle of the dividing cell?
a. prophase
c. metaphase
b. telophase
d. interphase
24. A body cell of a horse has 64 chromosomes. How many chromosomes are in the unfertilized egg of
a female horse?
a. 16
c. 64
b. 32
d. 128
25. A segment of mRNA is AGUACA; what did the original DNA strand look like?
a. UCAUGU
c. AGUACA
b. AGTACA
d. TCATGT