II. (Gene Interactions - Pleiotropism)

Question 1

____ is the joint role or influence of multiple genes on the same character or phenotype.

Answer 1

Gene Interaction

Question 2

In ____, the independent (non-homologous) genes located on the same or on different chromosomes interact with one another for the expression of a single phenotypic trait of an organism.

Answer 2

Interallelic Genetic Interactions

Question 3

In ____, two pairs of genes determine the same phenotype but are assorted independently and produce new phenotypes by mutual genetic interaction.

Answer 3

Non-epistatic Interallelic Genetic Interaction

Question 4

___ occurs when one gene masks or modifies the effect of another gene pair and alters the phenotype.

Answer 4

Epistasis

Question 5

___ occurs when the recessive allele of one gene masks the effects (phenotypic expression) of either allele of the second gene.

Answer 5

Recessive Epistasis

Question 6

____ is caused by the dominant allele of one gene, masking the action of either alleles of the other gene.

Answer 6

Dominant Recessive

Question 7

___ occurs when a dominant allele of one gene completely suppresses the phenotypic expression of alleles of another gene.

Answer 7

Dominant Suppression

Question 8

____ occurs when both gene loci have homozygous recessive alleles and both of them produce identical phenotypes thus generating the F2 9:7 phenotypic ratio.

Answer 8

Complementary Epistasis or Duplicate Recessive Epistasis

Question 9

___ occurs when the dominant alleles of both gene loci produce the same phenotype without cumulative effect, modifying the F2 phenotypic ratio into 15:1.

Answer 9

Duplicate Dominant Epistasis

Question 10

____ occurs when two genes are involved in the expression of the shape; each gene is completely dominant; interaction between the two loci produces a new phenotype.

Answer 10

Dominant Gene Interaction

Question 11

____ refers to the combined effects of genetic alleles at two or more gene loci that are equal to the sum of their individual effects.

Answer 11

Duplicate Genes with Additive/Cumulative Effect

Question 12

___ is the phenomenon of multiple effects (multiple phenotypic expressions) of a single gene; one gene influences two or more seemingly unrelated phenotypic traits.

Answer 12

Pleiotropism

Question 13

What are some examples of pleiotropy?

Answer 13

1. Phenylketonuria (PKU)
2. Marfan Syndrome
3. Porphyra Variegata
4. Sickle Cell Anemia
5. Fizzle Trait in Chickens
6. Deafness in Blue-Eyed, Purely White-Coated Cats

Question 14

With ___, where the affected individuals secrete an excessive quantity of amino acid phenylalanine in their urine, cerebrospinal fluid, and blood. They become short-stature, and mentally deficient, with widely spaced incisors, pigmented patches on the skin, excessive sweating, and with non-pigmented hairs and eyes.

Answer 14

Phenylketonuria

Question 15

___ refers to a human malady resulting from an autosomal dominant mutation in the gene encoding the connective tissue protein fibrillin.

Answer 15

Marfan Syndrome

Question 16

___ refers to when afflicted individuals cannot adequately metabolize the porphyrin component of hemoglobin when this respiratory pigment is broken down as red blood cells are replaced.

Answer 16

Porphyra Variegata

Question 17

____ refers to the mutation of a beta-globin gene that can cause various organ problems.

Answer 17

Sickle Cell Anemia

Question 18

____ can be seen as an effect of a dominant gene
that produces feathers that curled outward rather than lying flat against their bodies. Along with producing defective.

Answer 18

Fizzle Trait in Chickens