Answer:
7
Explanation:
There are always half the chromosomes in sex cells.
Immune System is the system that consists of proteins and cells.
<span>A population's growth is strongly influenced by the proportions of individuals in different age brackets, which in turn is influenced by economic development.</span>
Nitrogen and oxygen make up about 99%of the atmosphere. I'm not sure if it will help! But thats all I know.
