Question

A man and his wife are both heterozygous for brown eyes. they have six children all of whom have blue eyes.

Answer 1

The genetics of eye color involves multiple genes with dominant and recessive alleles. Heterozygous parents with brown eyes could have a child with green eyes if they both carry a green allele. In sex-linked traits like fruit fly eye color, crosses between certain genotypes produce predictable offspring ratios.

Step-by-step explanation:

Genetics of Eye Color:

The question addresses the inheritance of eye color in humans, which is a classic example of genetic inheritance. Eye color is determined by multiple genes, where the alleles for brown eyes are generally dominant over the alleles for blue eyes. If both parents are heterozygous for brown eyes (Bb), there is a 25% chance that any given child will inherit the blue eye allele from both parents (bb), resulting in blue eyes.

To answer the provided question: A couple produces a green-eyed child while both having brown eyes could be genetically possible if option (b) is true, stating 'Both parents are heterozygous, having the green trait on the green-blue eye gene'. This implies that each parent has one allele for green and one for brown, allowing for the possibility of a green-eyed child if the green alleles from each parent are inherited.

In the case of the fruit fly eye color genetics, different ratios such as '25% of the males are hemizygous dominant with red eyes and 50% of the male are hemizygous recessive with white eyes' demonstrate the principles of Mendelian inheritance with some additional complexity due to the sex-linked nature of the trait. A cross between a white-eyed male and a female heterozygous for red eye color will result in a ratio of 1:1 for red-eyed female and white-eyed male offspring.

Answer 2

The eye color of the children can be explained by the principles of inheritance and genetics. Both parents being heterozygous for brown eyes leads to a 25% chance of each child inheriting two recessive alleles for blue eyes.

Step-by-step explanation:

The eye color of the children can be explained by the principles of inheritance and genetics. In this case, both parents are heterozygous for brown eyes, which means that they have one dominant allele for brown eyes and one recessive allele for blue eyes. When they have children, each child has a 25% chance of inheriting two recessive alleles for blue eyes and therefore having blue eyes.