Answer:
Nonrenewable energy resources, like coal, nuclear, oil, and natural gas, are available in limited supplies. This is usually due to the long time it takes for them to be replenished. Renewable resources are replenished naturally and over relatively short periods of time.
The correct answer to this question is this one: they lacked oxygen. The earliest organisms were completely heterotrophic in nature because of the reason that they lacked oxygen. <span>A heterotroph is an organism that cannot fix carbon and uses organic carbon for growth. </span>
➜ <u>Mendel conducted breeding experiments with garden peas</u>:
[i] He studied plants (pure) of a tall/short varities.
[ii] He crossed them and obtained F1 progeny.
[iii] He found that F1 progeny was all tall plants.
[iv] He selfed the (hybrid) plants if F1 progeny.
[v] He found that in F2 progeny there were tall as well as short plants.
[vi] The three quarter plants were tall and one quarter was short.
(or any other contrasting character may be taken).
<u>Note</u>: Here, F1 means <u>First fillial generation</u> and F2 means <u>Second fillial generation</u>.
What do you mean <span>It has been observed that certain species of insects which had not previously caused significant harm have become serious pests. the best explanation for this phenomenon is that the pesticide killed off predators which had previously held this species in check. a mutation occurred in the species. the pesticide increased the vigor of the species. was able to be used by the pest as an additional food source is also a reproductive for some insect species. </span><span />
I'm pretty sure it's a community.
Hope this helps :)