Biology Life On Earth 11th Edition By Audesirk – Test Bank

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Gregor Mendel concluded that each pea has two units for each trait, and each gamete contains one 1)
unit. Mendelʹs ʺunitsʺ are now called
A) transcription factors. B) genes.
C) characters. D) chromosomes.
Answer: B
Chapter Section: 11.3
Learning Outcome: 11.1
2) Peas were a good organism of choice for Mendel because 2)
A) he could study one trait at a time. B) they cannot cross-fertilize.
C) they cannot self-fertilize. D) the traits were difficult to visualize.
Answer: A
Chapter Section: 11.3
Learning Outcome: 11.2
3) What is the ratio of phenotypes in the offspring produced by the cross Aa × Aa? Assume complete 3)
dominance for the trait.
A) 100% dominance
B) 50% dominant:50% recessive
C) 75% dominant:25% recessive
D) 25% dominant:75% recessive
E) 100% recessive
Answer: C
Chapter Section: 11.3
Learning Outcome: 11.2
4) If the allele for inflated pea pods (I) is dominant to the allele for constricted pods (i), then the cross 4)
Ii xii is expected to produce A) half with inflated and half with constricted pods.
B) 3/4 with inflated and 1/4 with constricted pods.
C) all peas with constricted pods.
D) 3/4 with constricted and 1/4 with inflated pods.
E) all peas with inflated pods.
Answer: A
Chapter Section: 11.3
Learning Outcome: 11.2
5) According to the law of segregation 5)
A) pairs of alleles on homologous chromosomes separate during the formation of gametes.
B) there is an independent assortment of nonhomologous chromosomes during meiosis.
C) each individual carries a single copy of each ʺfactor.ʺ
D) the sex chromosomes of males and females differ.
E) pairs of alleles fuse during the formation of gametes.
Answer: A
Chapter Section: 11.3
Learning Outcome: 11.2
6) According to the law of segregation, in an organism with the genotype Aa 6)
A) one-half of the gametes get the A allele and one-half get the a allele.
B) three-quarters of the gametes get the A allele and one-quarter get the a allele.
C) one-quarter of the gametes get the A allele and three-quarters get the a allele.
D) all of the gametes get the a allele.
E) all of the gametes get the A allele.
Answer: A
Chapter Section: 11.3
Learning Outcome: 11.2
7) A recessive allele is one 7)
A) that is not expressed as strongly as a dominant allele.
B) that appears only in a heterozygote.
C) that must be lethal in the homozygous condition.
D) that produces no effect when present in the homozygous condition.
E) whose effect is masked when paired with a dominant allele.
Answer: E
Chapter Section: 11.3
Learning Outcome: 11.2
8) Which of the following statements about genotypes and phenotypes is TRUE? 8)
A) Matings between individuals with recessive phenotypes produce offspring with dominant
phenotypes. B) Individuals with the same phenotype might have different genotypes.
C) Individuals with the same genotype might have different phenotypes.
D) Matings between individuals with dominant phenotypes cannot produce offspring with
recessive phenotypes.
Answer: B
Chapter Section: 11.3
Learning Outcome: 11.3
9) If, in a heterozygous individual, only one allele is expressed in the phenotype, that allele is 9)
A) potent. B) dominant. C) haploid. D) recessive. E) normal.
Answer: B
Chapter Section: 11.3
Learning Outcome: 11.3
10) The physical manifestation of an organismʹs genes is its 10)
A) environment.
B) genotype.
C) phenotype.
D) number of chromosomes.
E) genetic code.
Answer: C
Chapter Section: 11.3
Learning Outcome: 11.3