Gene S Controls the Sharpness of Spines in a Type

question 44

Multiple Choice

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. The relationship between genes S and N is an example of which of the following inheritance patterns?

• A) incomplete dominance
• B) epistasis
• C) pleiotropy
• D) codominance

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Definitions:

DNA Molecules

The molecules containing the genetic instructions for the development, functioning, growth, and reproduction of all known living organisms and many viruses.

Genetic Code

A set of rules by which information encoded in genetic material (DNA or RNA sequences) is translated into proteins by living cells.

One-cell Organisms

Living entities consisting of a single cell, capable of performing all necessary life functions, also known as unicellular organisms.

Specific Protein

A protein with a unique structure and function, distinguishing it from other proteins by its specific biological activity or regulatory role.