Category 2

12 Sexual reproduction in animals depends on the production of gametes. Which of these processes produces gametes in animals?

• Mitosis

• Fertilization

• Meiosis

• Binary fission

17 The sequence of nitrogenous bases in DNA varies widely. The sequence of the bases in DNA is most important for which of the following?

• Providing the instructions for the traits of an organism

• Preventing mutations from occurring during DNA replication

• Allowing the DNA to have the shape necessary for replication

• Helping form the sugar-phosphate backbone of DNA molecules

28 In 1917 the biologist Thomas Hunt Morgan conducted studies in which he kept some caterpillars in the dark and placed some others under red, green, or blue lights. Exposure to red light produced butterflies with brightly colored wings. Exposure to green light resulted in dark-colored wings. Exposure to blue light or no light resulted in pale-colored wings. What was the most likely conclusion of Morgan’s research?

• The pigment in butterfly wings absorbs light from the environment.

• The phenotypic expression of wing shape depends on color pigmentation in butterflies.

• The genes regulating wing color in butterflies are influenced by environmental factors.

• Caterpillars exposed to red and green light are healthier than caterpillars exposed to no light or blue light.

30 Lactose is found in milk products. It is converted by the body into a usable form in a series of chemical reactions. The diagram shows the series of reactions that convert lactose into a usable form. If Enzyme 2 is denatured, the levels of which substance will increase?

• Lactose

• Galactose

• Galactose-1-phosphate

• Glucose-6-phosphate

31 The picture below shows a person’s karyotype. Which of the following can best be determined by examining this karyotype?

• The presence of an additional chromosome

• The presence of a homozygous genotype

• The person’s genome

• The person’s phenotype

39 Sickle-shaped red blood cells result from a mutation in the gene that codes for hemoglobin. This mutation results in sickle-cell anemia. A partial sequence of bases from a normal hemoglobin gene and a sequence that results in sickle-cell anemia are shown. What type of mutation is depicted in this sequence?

• Substitution

• Insertion

• Deletion

• Frameshift

42 Genome maps provide the DNA sequences of chromosomes. Some scientists have compared the genome maps of a hedgehog and a sloth. What do these genome maps allow the scientists to determine?

• The color patterns of the offspring of each species

• How much the size ranges of the two species differ

• The methods of protein synthesis that each species uses

• How closely related the two species are to each other

43 Tomato plants usually have hairy stems. Hairless stems are present in tomato plants that are homozygous recessive for this trait. If the stem characteristics are determined by a single gene, what is the expected outcome of crossing two tomato plants that are heterozygous for hairy stems?

• 75% hairy stems: 25% hairless stems

• 100% hairy stems

• 100% hairless stems

• 50% hairy stems: 50% hairless stems

52 In 1952 Rosalind Franklin took the x-ray photograph shown below, which gave the world its first look at DNA. By studying this photograph, scientists gained knowledge about the —

• role of DNA in protein synthesis

• mutation of nucleotide sequences in DNA

• sequence of DNA that makes up the human genome

• double-helix structure of DNA

1 The four butterflies in the illustrations represent the offspring in the F 1 generation. Which statement is best supported by the phenotypes of these offspring?

• The F1 generation is composed only of males.

• Two of the offspring in the F1 generation will not be able to reproduce.

• The F1 generation is the result of a dihybrid cross.

• Two of the offspring in the F1 generation will experience a spontaneous mutation.