Chapter Questions
The ______ of an organism is determined by the information in the DNA, and the ______ is determined largely by proteins.a. phenotype; genotypeb. locus; phenotypec. genotype; phenotyped. genotype; sex-linkagee. None of these are correct.
Which of the following terms refers to variations in a gene?a. locusb. carrierc. dominanced. allelese. None of these are correct.
In which of the following can the phenotype be used to accurately predict the genotype?a. homozygous recessiveb. homozygous dominantc. heterozygousd. None of these are correct.
What possible gametes can be produced by $A a B b ?$a. $A a, B b$b. $A, a, B, b$c. $A B, a b$d. $A B, A b, a B, a b$
The genotype of an individual with the dominant phenotype can be determined best by reproduction witha. a homozygous recessive individualb. a heterozygote.c. the dominant phenotype.d. None of these are correct.
In a dihybrid cross of $A a B b \times A a B b,$ what is the probability that offspring will have the dominant phenotype for trait A but the recessive phenotype for trait B?a. $1 / 16$b. $3 / 16$c. $7 / 16$d. $9 / 16$e. None of these are correct.
Cystic fibrosis is a recessive trait. If two carriers have children, what is the probability that their child will have the disease?a. $0 \%$b. $25 \%$c. $50 \%$d. $75 \%$e. $100 \%$
Which of the following is correct regarding a dominant autosomal disorder?a. An allele in one of the parents may cause the disease in the offspring.b. Heterozygotes are affected by the disorder.c. Two unaffected parents do not produce offspring with the disorderd. Two affected parents may produce offspring without the disorder.e. All of these are correct.
Which of the following disorders is caused by a loss of enzymes in the lysosomes of the cell?a. osteogenesis imperfectab. cystic fibrosisc. Tay-Sachs diseased. Marfan syndromee. Huntington disease
Which of the following is not a feature of multifactorial inheritance?a. Effects of dominant alleles are additive.b. Genes affecting the trait may be on multiple chromosomes.c. Environment influences phenotype.d. Recessive alleles are harmful.
If a child has type $\mathrm{O}$ blood and the mother is type $\mathrm{A}$, then which of the following might be the blood type of the child's father?a. A onlyb. $B$ onlyc. $\mathrm{O}$ onlyd. $A$ or $O$e. $A, B,$ or $O$
A trait in which the heterozygotes have a phenotype that is intermediate between the dominant and recessive phenotypes is an indication ofa. codominance.b. sex-linked trait.c. incomplete dominance.d. pleiotropy.e. None of these are correct.
Which of the following terms may be used to describe a disease that has multiple phenotypes?a. multifactorialb. codominancec. incomplete dominanced. sex-linkede. pleiotropy
A couple wish to have children, but the father has an X-linked recessive trait. Assuming that the mother does not carry the trait, what percentage of their sons may inherit the trait?a. $0 \%$b. $25 \%$c. $50 \%$d. $75 \%$e. $100 \%$
A mother who is heterozygous for an X-linked recessive trait has children with a man who has the trait. What percentage of their daughters will exhibit the trait?a. $0 \%$b. $25 \%$c. $50 \%$d. $75 \%$e. $100 \%$