Genetics and the Environment Quiz

Which of the following is the molecular cause of sickle cell anemia?

• Deletion of a base in the gene encoding hemoglobin

• Substitution of adenine for thymine in the gene encoding hemoglobin

• A duplication of the hemoglobin gene

• Insertion of a nucleotide in the hemoglobin gene

Cystic fibrosis is caused by mutations in which gene?

• CFTR

• BRCA1

• TP53

• HBB

The molecular basis of phenylketonuria (PKU) is due to a deficiency in which enzyme?

• Phenylalanine hydroxylase

• Tyrosinase

• Homogentisate oxidase

• Branched-chain amino acid transaminase

In a dihybrid cross (AaBb × AaBb), what is the probability of producing an offspring with the genotype AABb?

• 1/16

• 1/4

• 1/8

• 1/2

What is the expected phenotypic ratio of a cross between two heterozygous individuals (Tt × Tt) for a simple Mendelian trait?

• 1:1

• 3:1

• 2:2

• 1:2:1

In incomplete dominance, the heterozygous genotype results in:

• A phenotype that is intermediate between the two homozygous phenotypes

• A phenotype identical to the dominant homozygote

• A phenotype identical to the recessive homozygote

• A completely new phenotype

Which of the following is an example of codominance?

• Red and white flower crossing to produce pink flowers

• A person with type AB blood

• A blue cat crossed with a yellow cat to produce green cats

• A person with sickle cell anemia

The genetic code is considered universal because:

• It is the same in all living organisms

• It can be translated into different proteins

• It codes for all types of mutations

• It is found in all organisms' mitochondria

Which of the following is the correct sequence of amino acids specified by the codons: AUG, GCU, UAC?

• Methionine, alanine, tyrosine

• Methionine, tyrosine, alanine

• Tyrosine, methionine, alanine

• Alanine, methionine, tyrosine

Which of the following mutations does NOT alter the amino acid sequence of the resulting protein?

• Silent mutation

• Missense mutation

• Nonsense mutation

• Frameshift mutation