The number of organisms in a population which die each year is known as ?

Death rate

Explanation:

It’s a cycle that continues on with people dying each year so it’s called a death rate since it’s continuing number by number each year for the number of organisms in the population to decrease.

its 42

i say its d?

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: