Answer:
This disorder is caused by a recessive allele, its inheritance is sex-linked.
Explanation:
The disorder affects boys born to unaffected parents, this means that at least one of them has to be a carrier of the allele which causes the disease. So, if the allele was dominant, it would express in parents and sons. But, in this case, only is expressed in sons, so it can´t be dominant. Moreover, this condition has a sex-linked inheritance because it is always seen in boys and never in girls. This happens due to boys only have an X chromosome, so if they inherit the recessive allele of the disease, they will express it. On the other hand, girls have two X chromosomes, so if they inherit one copy of the recessive allele, they will be carriers and they won't be affected.
This disorder is never seen in females because they need to have two copies of the recessive allele. However, to have double copy, they should inherit one copy from their mothers and one copy of their fathers, but boys with the allele are affected and they die in early teens without having progeny. Therefore, a girl can't have a "carrier-father", so they will never have two copies to express the disorder.
Answer:
<u><em>Reproduction</em></u> of cells is one of the processes that help multicellular organisms maintain homeostasis.
Explanation:
In biology, homeostasis can be described as the capability of an organism to maintain its constant internal environment despite the changes in the external environment.
External factors like pathogens in the environment tend to kill cells in our body like the skin cells and the immune cells. Through the process of cell division, our cells can reproduce and hence, maintain an equilibrium of the internal conditions.
Reproduction of cells also causes growth. Hence, the process of reproduction of cells maintains homeostasis.
Answer:
C. rr
Explanation:
The dominant genotype will always be denoted by the capital version, or in this case R.
The round pea shape is dominant to the wrinkled pea shape, which means that, in the Punnett Square, the combinations of RR, Rr, rR, will all come out to be round pea shape.
The last box, rr, would be the one that gives the wrinkled phenotype.
In this case, by ratio, wrinkled phenotype show up 25%
by ratio, round phenotype show up 75%.
The DNA copies are moved to opposite ends of the cell.
