Prophase 1 of meiosis <span>relative to the number of chromosomes of a given species, accounts for a significant amount of genetic variation in gametes.</span>
<span>grass → rabbits → snakes → hawks. This chain supports the assumption that each population supports the next tropic level
because it tells about the next tropic level and flow of energy from one to the next
so correct option i conclude is A
hope it helps</span>
Answer:
Explanation:
Duchenne muscular dystrophy acts as a X-linked recessive disease. Which means the gene sits on the X chromosome, and you need two bad copies to show disease (for females) and one bad copy (to show in males).
Now from our knowledge, we know males are XY and females are XX. Males have only one copy of the X chromosome from their mother and one copy of the Y chromosome from their father, thus if they get the mutated version of the gene that causes this disease, they will get the disease. However, if a female has a mutated version of gene on one of the X chromosome, the other X chromosome could have a normal gene and that normal gene would take over and produce a normal phenotype/function.
Since, boys only have one X chromosome, if they get the mutated gene they will get the disease, whereas females have two X chromosome (so even if one copy is bad and the other is good, the good version can take over, however boys don't have this) thus mostly male children are affected by this.