Answer: i think, Endochondral ossification occurs at two distinct sites in the vertebrate long bone – the primary (diaphyseal) and the secondary (epiphyseal) sites of ossification. Bone development initiates at the primary site. The secondary (epiphyseal) site is under independent control and is ossified later (Figure 1b).
I would say the answer is a .
Answer;
C. His mother carried at least one allele for that trait
Explanation;
-Men have a single allele of each gene on the X chromosome, inherited from their mother, and a single allele of each gene on the Y chromosome, from their father.
-A sex-linked trait is a trait that is controlled by a gene or an allele located on the sex chromosome.
-X-linked traits are maternally inherited from carrier mothers or from an affected father. Each son born to a carrier mother has a 50% probability of inheriting the X-chromosome carrying the mutant allele.
The answer will be B. It is common sense