Question

page(s) 136 - 137 7.3. illustrate mendels laws of segregation and independent assortment. a breeder of ornamental koi fish breeds two red - eyed fish with long fins. the fry (baby fish) that hatch include 19 red - eyed, long - finned fish, 6 black - eyed, long - finned fish, 5 red - eyed, short - finned fish, and 2 black - eyed, short - finned fish. which of the following statements accurately describes inheritance of these traits in koi? accurate both parents were heterozygous. the law of independent assortment describes how these two traits are inherited. the long - finned trait is recessive. the red - eyed trait is dominant. the law of segregation describes how these two traits are inherited. one of the parents was homozygous recessive.

Explanation:

• Both parents were heterozygous: Since the cross between two red - eyed, long - finned fish produced offspring with different phenotypes (black eyes and short fins), the parents must have had hidden recessive alleles, meaning they were heterozygous.
• The law of independent assortment: The presence of four different phenotypes in the offspring (red - eyed long - finned, black - eyed long - finned, red - eyed short - finned, black - eyed short - finned) shows that the alleles for eye color and fin length assort independently during gamete formation, which is in line with the law of independent assortment.
• The red - eyed trait is dominant: The majority of the offspring have red eyes (19 red - eyed long - finned + 5 red - eyed short - finned = 24 red - eyed fish out of a total of 19 + 6+5 + 2=32 fish), suggesting that red - eyed is the dominant trait.

• The long - finned trait is recessive: This is incorrect. If long - finned were recessive, and both parents were long - finned (assuming they are homozygous recessive for fin length), all offspring should be long - finned. But there are short - finned offspring, so long - finned is dominant.
• The law of segregation: While segregation occurs (as alleles separate during gamete formation), the presence of multiple traits and multiple phenotypes is better explained by the law of independent assortment.
• One of the parents was homozygous recessive: If one parent was homozygous recessive for either trait, the phenotypic ratios would be different. For example, if one parent was homozygous recessive for eye color (assuming red is dominant), we would not get the observed ratio of red - eyed to black - eyed offspring.

Answer:

Both parents were heterozygous, The law of independent assortment describes how these two traits are inherited, The red - eyed trait is dominant.