Name: ___________________________________ Period: ________ Date: ________________
ID: A
Genetics practice test
Multiple Choice
Identify the choice that best completes the statement or answers the question. Indicate your answer choice with
an UPPER CASE letter in the space provided.
____
1. Usually, an egg cell from a human female contains
A. one X chromosome and one Y chromosome. B. one X chromosome. C. one Y chromosome.
D. two X chromosomes. E. two Y chromosomes.
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2. The three-base sequence of DNA codes for
A. one protein. B. one strand of mRNA. C. one amino acid. D. one polypeptide. E. one
strand of tRNA.
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3. The bases are bonded to what part of the backbone of the DNA molecule?
A. the 1' carbon atom of the sugar molecule B. the 2' carbon atom of the sugar molecule C. the 3'
carbon atom of the sugar molecule D. the 4' carbon atom of the sugar molecule E. the 5' carbon
atom of the sugar molecule
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4. What is epistasis?
A. A phenotype is inherited only from the mother. B. A gene is expressed in only one sex.
C. One trait is affected by several genes. D. One gene affects the way others are expressed.
E. One gene influences several phenotypes.
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5. The segregation principle states that in sexually reproducing diploid organisms the two copies of each
gene
A. move together as a unit during meiosis. B. separate from each other during mitosis. C. will
both wind up in either the sperm or egg. D. must always be the same allele. E. segregate from each
other during meiosis.
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6. What form of RNA carries instructions from the nucleus to the ribosome?
A. tRNA B. mRNA C. sRNA D. rRNA E. bRNA
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7. The "language" of the genetic code of DNA uses an alphabet of
A. nucleotide bases. B. proteins. C. amino acids. D. sugars. E. phosphate molecules.
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8. The most important experimental result that suggested to Watson and Crick that DNA was in the form
of a helix was
A. the finding of Chargaff that DNA always had equal amounts of A and T and equal amounts of G and
C. B. Griffith's results with transformation. C. the discovery that DNA is wound around histone
proteins. D. X-ray data from Rosalind Franklin working with Maurice Wilkin. E. understanding
DNA replication.
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9. The genetic makeup of a particular trait in an individual is its
A. dominance. B. heterozygosity. C. genotype. D. phenotype.
E. filial.
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10. A package of histones with DNA wrapped around them forms spherical structures called
A. nucleoli. B. chromatin. C. nucleosomes. D. ribosomes. E. lysosomes.
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11. The anticodon of the tRNA molecule base pairs with
A. DNA. B. mRNA. C. amino acids. D. polypeptides. E. rRNA.
1
Name: ______________________
ID: A
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12. Genes are composed of
A. DNA. B. proteins. C. chromosomes. D. carbohydrates. E. lipids.
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13. In eukaryotes, transcription occurs in the
A. cell membrane. B. cytoplasm. C. mitochondria. D. nucleus. E. ribosome.
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14. An organism with two copies of the same allele is said to be
A. homozygous. B. heterozygous. C. phenotypic. D. genotypic. E. a hybrid.
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15. The two subunits of the ribosome join during
A. initiation of translation. B. promotion of transcription.
translation. E. termination of transcription.
C. elongation. D. termination of
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16. The structure of DNA was determined primarily by
A. Mendel. B. Watson and Crick. C. Pauling. D. Hershey and Chase. E. Griffith.
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17. Which is not true of DNA replication?
A. It occurs in the S phase of the cell cycle. B. It functions similarly for all organisms. C. It is
semiconservative. D. Both strands are synthesized in one direction only. E. Both strands are
synthesized continuously.
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18. Normal human body cells contain how many chromosomes?
A. 22 B. 23 C. 46 D. 44 E. 42
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19. Pedigrees are
A. used by geneticists to determine the sequence of an individual's genes. B. histories of families
with regard to particular genetic traits. C. used only for dogs, cats, and horses. D. mutated alleles
capable of causing genetic disorders. E. characteristics that are apparent in an individual.
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20. Tall corn plants (T) are dominant to dwarf plants (tt). Solid green leaves (G) are dominant to leaves
with a white tip (gg). A cross between two corn plants yielded the following phenotypes: 51 tall plants
with a white tip on their leaves; 43 dwarf plants with solid leaves; 48 dwarf plants with white tips on
their leaves; 45 tall plants with solid leaves. What are the genotypes of the parents that produced these
plants?
A. TtGg × TtGg B. TtGg × Ttgg C. ttGG × TTgg D. TtGg × ttgg E. None of the above
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21. With respect to genetic traits, what is the opposite of recessive?
A. regressive B. progressive C. dominant D. subordinant E. hybrid
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22. DNA and RNA are similar in that both
A. contain the same sugar. B. are double-stranded molecules. C. contain nitrogenous bases.
D. are in the form of a double-helix. E. are very long molecules.
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23. We refer to the DNA code as being redundant or repetitive. This means that
A. each triplet codes for one amino acid. B. some codons code for the same amino acid. C. one
codon codes for one amino acid. D. each triplet codes for a different amino acid. E. a single triplet
may code for more than one amino acid.
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24. The anticodon
A. is found on mRNA. B. has the same sequence as the codon. C. is a sequence found on DNA.
D. helps the ribosome begin translation. E. helps bring in the correct amino acid to add to the
growing polypeptide chain.
2
Name: ______________________
ID: A
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25. When looking at a table depicting the genetic code, the base sequences signify
A. DNA. B. mtDNA. C. mRNA. D. tRNA. E. rRNA.
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26. Promoters
A. determine the start of DNA strand separation. B. are required to end transcription. C. are a
sequence of RNA nucleotides. D. are involved in determining the start of translation. E. aid in
complementary base pairing.
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27. Different forms of a gene are known as
A. alleles. B. hybrids. C. recessives. D. genotypes. E. phenotypes.
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28. A gene on the X chromosome is said to be
A. heterozygous. B. sex limited. C. x-linked. D. bipolar. E. a mutation.
____
29. The physical characteristics of an organism resulting from its genes are known as the organism's
A. alleles. B. hybrids. C. recessive characteristics. D. genotype. E. phenotype.
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30. Mendel observed that dominant traits
A. are only expressed in hybrids. B. were absent in the F1 generation of pea plants that he used in
his experiments. C. were the only trait seen in the F2 generation of pea plants in his experiments.
D. are expressed in all plants. E. are seen in all the F1 hybrid pea plants in his experiments.
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31. An allele is
A. the dominant form of a gene. B. an alternate form of a gene. C. always recessive. D. the
main factor determining a trait. E. always one of a pair.
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32. The ABO blood type gene is an example of ___________, which means that heterozygotes display
two phenotypes at the same time.
A. advanced hybridism B. fading C. incomplete dominance
E. cross-fertilization
D. codominance
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33. In DNA, cytosine bonds to guanine. In RNA, cytosine bonds to
A. thymine. B. cytosine. C. uracil. D. guanine. E. adenine.
____
34. tRNA molecules are composed of
A. DNA. B. nucleotides. C. amino acids D. polypeptides. E. lipids.
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35. Mendel correctly surmised that the 3 dominant:1 recessive phenotypic ratio seen in the F2 generation
pea plants was due to
A. a tendency to have more fertilization events yielding homozygous dominant than homozygous
recessive. B. homozygosity. C. genotypic selection. D. random combination of sperm and egg
with respect to the allele carried. E. certain phenotypes having a selective advantage.
3
Name: ______________________
ID: A
Matching
Match the following with the correct descriptive term.
A. phenotype
B. recessive phenotype
C. homozygous
D. heterozygous
E. alleles
F. gene
G. dominant allele
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36.
37.
38.
39.
40.
LL
Ll
Determines plant height
L and l
Long-stemmed plant
Match the following descriptive terms with DNA, RNA, or both
A. DNA
B. RNA
C. both DNA and RNA
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____
____
____
____
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41.
42.
43.
44.
45.
46.
Carries the genetic information to the ribosome
Can exit the nucleus
Contains the base uracil
Has a sugar-phosphate backbone
Is usually double-stranded
Has one strand that serves as a template during transcription
Match the following codons with their corresponding amino acid.
A. arg
B. stop
C. met/start
D. asn
E. val
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____
____
____
____
47.
48.
49.
50.
51.
UAA
AAU
AGG
AUG
GUU
4
Name: ______________________
ID: A
Match the following terms with their characteristics.
A. building block of DNA
B. joins nucleotides during DNA replication
C. molecule associated with RNA
D. cytosine, guanine, adenine, and thymine
E. spool of protein associated with DNA
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____
____
____
52.
53.
54.
55.
Nucleotide
Histone
DNA polymerase
Bases of DNA
5
Genetics practice test [Answer Strip]
A
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12.
C
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25.
D
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13.
A
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26.
ID: A
A
_____
14.
B
_____
1.
A
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15.
C
_____
C
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28.
2.
B
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16.
A
_____
D
_____
3.
4.
A
_____
27.
E
_____
17.
E
_____
29.
E
_____
30.
C
_____
D
_____
F
_____
E
_____
A
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36.
37.
38.
39.
40.
B
_____
B
_____
B
_____
C
_____
A
_____
A
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41.
42.
43.
44.
45.
46.
B
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D
_____
A
_____
C
_____
E
_____
47.
48.
49.
50.
51.
C
_____
18.
B
_____
31.
B
_____
19.
E
_____
5.
D
_____
32.
D
_____
20.
B
_____
6.
A
_____
7.
D
_____
33.
B
_____
34.
C
_____
21.
D
_____
8.
D
_____
35.
C
_____
22.
B
_____
23.
C
_____
9.
C
_____
10.
C
_____
11.
E
_____
24.
A
_____
E
_____
B
_____
D
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52.
53.
54.
55.