CLEP Biology Genetics & Biological Diversity 2

Question 1

In a dihybrid cross between two organisms heterozygous for both traits (AaBb × AaBb), what fraction of offspring will express both dominant phenotypes?

Accepted Answer

9/16

Answer

The 9:3:3:1 ratio means 9/16 offspring express both dominant phenotypes.

Question 2

Which of the following best describes incomplete dominance?

Accepted Answer

The heterozygote shows a blended intermediate phenotype

Answer

In incomplete dominance, the heterozygote phenotype is intermediate between the two homozygous phenotypes (e.g., red × white = pink).

Question 3

A bacterium that can synthesize all needed amino acids is best described as a:

Accepted Answer

Prototroph

Answer

A prototroph is a wild-type microorganism capable of synthesizing all required organic compounds from inorganic precursors.

Question 4

Which domain includes organisms with peptidoglycan in their cell walls and no membrane-bound nucleus?

Accepted Answer

Bacteria

Answer

Bacteria have cell walls containing peptidoglycan and lack a membrane-bound nucleus.

Question 5

During meiosis, genetic variation is increased by crossing over, which occurs during:

Accepted Answer

Prophase I

Answer

Crossing over (recombination) between homologous chromosomes occurs during Prophase I of meiosis.

CLEP Practice Test

CLEP Practice Test

CLEP Biology Genetics & Biological Diversity 2