Question

when the homozygous dominant form of a gene codes for red and the homozygous form a gene codes for white, but the heterozygous form of the gene codes for red and white this is an example of what form of inheritance?
codominance
incomplete dominance
epistasis
sex linkage
question 2
1 pts
when the dominant form of gene 1 codes for the expression of gene 2 while the recessive form of gene 1 codes to stop the expression of gene 2 this is an example of what form of inheritance?
codominance
incomplete dominance
epistasis
sex linkage

Explanation:

• Codominance: In codominance, both alleles in a heterozygous individual are fully expressed. For example, if a gene has alleles for red (RR - homozygous dominant) and white (rr - homozygous recessive), the heterozygous (Rr) shows both red and white (like in some flower petal colorations or human blood types like AB where both A and B antigens are present).
• Incomplete Dominance: Here, the heterozygous shows an intermediate phenotype. For example, if red (RR) and white (rr) are the homozygous phenotypes, the heterozygous (Rr) might be pink (a blend, not both colors).
• Epistasis: One gene affects the expression of another gene. For instance, in gene - gene interaction, gene 1 (say with alleles \(A\) (dominant) and \(a\) (recessive)) can control the expression of gene 2 (with alleles \(B\) and \(b\)). If \(A\) allows \(B\) to be expressed and \(a\) prevents \(B\) expression, it is epistasis.
• Sex - linkage: Genes are located on sex chromosomes (usually X in humans). Traits show different inheritance patterns in males and females. For example, color - blindness (more common in males as they have only one X chromosome).

For the first question: Since the heterozygous shows both phenotypes (red and white from the two alleles), it is codominance.
For the second question: Since one gene (gene 1) controls the expression of another gene (gene 2), it is epistasis.

Answer:

1. Codominance
2. Epistasis