Refer to the Following Information to Answer the Questions Below

question 69

Multiple Choice

Refer to the following information to answer the questions below.
Gene S controls the sharpness of spines in a type of cactus. Cacti with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cacti have dull spines. At the same time, a second gene, N, determines whether or not cacti have spines. Homozygous recessive nn cacti have no spines at all.
-If doubly heterozygous SsNn cacti were allowed to self-pollinate, the F₂ would segregate in which of the following ratios?

• A)3 sharp-spined:1 spineless
• B)1 sharp-spined:2 dull-spined:1 spineless
• C)1 sharp-spined:1 dull-spined:1 spineless
• D)1 sharp-spined:1 dull-spined
• E)9 sharp-spined:3 dull-spined:4 spineless

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Definitions:

Metabolic Processes

The chemical reactions that occur within a living organism in order to maintain life, including digestion and the production of energy.

BMR

Basal metabolic rate, which is the rate of energy expenditure per unit time by endothermic animals at rest.

ACTH

Adrenocorticotropic hormone, a hormone produced by the pituitary gland that stimulates the adrenal glands to release cortisol.

Premature Old Age

A condition in which an individual shows signs and experiences conditions associated with aging earlier than the expected chronological age.