Examine how nearly all energy for life comes directly or indirectly from the sun, given that heterotrophs get their energy from the food they eat

Explanation:

It is very accurate that only autotophs like plants (producers) can harness the sun's energy and use it to make their own food in form of organic molecules (glucose) in a process called PHOTOSYNTHESIS, but certain animals called called HERBIVORES or Primary consumers in the ecosystem are strictly dependent on this photosynthetic plants to obtain energy. They obtain this energy by feeding on the plants.

Other animals or organisms called CARNIVORES or Secondary consumers feed on these primary consumers and energy gets transferred to them in the process. In a nutshell, one organism is dependent on another organism for energy. Now, tracing it back to where it all started, we'd realize that plants called PRODUCERS are dependent on the SUN's energy.

This implies that since the organism that started the feeding chain is dependent on the energy from sun, all other life forms are directly or indirectly dependent on the SUN i.e. without the sun's energy, plants can get energy; without plants, herbivores can't get energy and so on like that.

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation:

a. to encourage apoptosis