How can the environment affect population size?

it's about animals in the wildlife

If the environment gets polluted or treated poorly, than there will be less animals. If the environment grows a bunch of grass however, there will be more animals eating the grass which increases the population. But if they run out of grass, then the animals die.

The environment can affect the population size by different factors. Some examples are climate, food, space, etc. If the environment lacks any of these, the population will decrease since it will not have the necessary survival needs.

the overall balanced equation

6co2 + 6h2o > c6h12o6 + 6o2

sunlight energy

where: co2 = carbon dioxide

h2o = water

light energy is required

c6h12o6 = glucose

o2 = oxygen

thinking it would be d not too sure but i think it's right