Answer:
The correct option is<em> A. Active transport moves substances against the concentration gradient.</em>
Explanation:
Active transport can be described as a transport mechanism in which molecules tend to move against the concentration gradient i.e from an area of lower concentration to an area of higher concentration. Energy is needed for this process to occur.
Facilitated diffusion can be described as a phenomenon is which molecules move along the concentration gradient i.e from a higher concentration to a lower concentration with the help of trans- membrane integral proteins
Answer:
6,25%
Explanation:
Considering that the couple has a trait of sickle cell anemia, we know that both are heterozygous for the disease (Aa) and therefore can have children with the following genotypes:
Parents: Aa X Aa
Children: AA(A x A), Aa(A x a), Aa (a x A) and aa(a x a)
Knowing that sickle cell anemia only occurs in homozygous individuals, the probability for children to have the disease according to each crossing is:
A x A = 1/4 = 25%
A x a = 1/4 = 25%
a x A = 1/4 = 25%
a x a = 1/4 = 25%
The probability of forming each homozygous child (aa) is 1/4 or 25%. Since they are two children, the probability of both having sickle cell anemia is calculated by multiplying the probability of each, so:
1/4 × 1/4 = 1/16 = 0.0625 = 6.25%
It is concluded that the probability of a heterozygous couple for sickle cell anemia to have two children with the disease is 6.25%.
Answer: there are islands
Explanation:
Answer:E
Explanation:I think it is