Awoman gives birth to a set of fraternal twins: a girl and a boy. she also passes on a color-blindness gene. which of the children is more likely to be color-blind?

The boy

Explanation:

Color blindness is a X-linked trait. The alleles representing the gene for color blindness are usually located on the X-chromosome of the human's sex chromosome.

The female sex chromosome is XX, hence, the two chromosomes have to carry the alleles for color blindness for the girl to be color-blind. Otherwise, she's going to be a carrier for the abnormality.

The male's sex chromosome is XY, only one allele is needed for the male to become affected by color blindness.

A male child always inherit his X chromosome from the mother while one of the female's X chromosome is always from the father and the other one from the mother.

Hence, the male child is more likely to be color-blind out of the twin.

b. lithosphere, asthenosphere, mesosphere   is the answer most likely

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs