Search the NIH gene database for the term colorblindness. Use the results of the database search to explain how a father and mother who are not colorblind could have a son who is colorblind. Your model can be a pedigree chart, a Punnett square, or a diagram of chromosomes.

Answer/Explanation:

Red/green colorblindness is a recessive, X-linked condition. That means that the affected gene is on the X chromosome, and that the phenotype will only be present if there is no "healthy" gene, which is dominant to the mutated gene.

For two unaffected people to have an affected son, the mother must be a carrier. Remember, females have two X chromosomes and males have one. So if a female is a carrier of the colorblindness mutation, she will have one copy of the mutation and one normal copy of the gene, and will therefore be unaffected.

The punnet square (attached) shows that all their female children would be unaffected (have the B gene), but 1:2 male children would be colorblind, as their only copy of the gene is mutated (b).

spiders belong to a group of arachnids.

arachnids have the following traits :

they have two body parts.

they have eight legs unlike insects which have 6 legs.

they have no wings.

these traits distinguish them from insects.

the information that antonio is doubting us the statement that spiders differences are as a result of being first to evolve.

this is because the evolution of one species is independent of the other species.