Answer:
<u>Hyaline cartilage model formation</u> is the event that should proceed all others during endochondral ossification.
Explanation:
- The Greek root word for cartilage is ‘chondro’. Endochondral ossification is the systematic formation or replacement by bones to develop the growing skeleton from a growing cartilage.
- Mesenchymal cells are converted to chondroblasts to chondrocytes and then to a hyaline cartilage model. This leads to the development of long bones of both the axial (ribs) and the appendicular skeleton (limb bones).
- The sites of endochondral ossification are the physis, epiphysis, and cuboidal bones.
- The five main steps involved in endochondral ossification are –
- Bone collar formation
- Cavitation
- Periosteal bud invasion
- Diaphysis elongation
- Epiphiseal ossification
Oxygen is the heart of the lungs
The person should be a male.
Only male carries XY chromosomes, meanwhile female carries XX chromosomes. "Heterozygous for the X and Y chromosomes" means that the person have both X and Y chromosomes in their cells, therefore only males fits the description.
This is also why the birth rate of girl or a boy is always 50%, it is because the sex of a person is only determined by the sperm from a male. Each sperm either carries a X or a Y chromosome, never the both. Therefore, the chances of a X or a Y sperm fertilising an X egg is always 50%, also explains why both female or male must have at least one X chromosome because an egg always carry an X.
