Question

Who determines whether the two organism of a species will be exactly similar or not...???

Answer 1

According to the most widely usedspecies definition, the biological speciesconcept, a species is a group oforganisms that can potentially interbreed, or mate, with one another to produce viable, fertile offspring. In this definition, members of the same speciesmust have the potential to interbreed.

Answer 2

Hi

Here's your answer

There is no “who”. Similarity depends on 3 things: genetics, embryonic development (for organisms that do that), and environment.

A lot goes into “exactly similar”. Identical twins will have differences based on their environment and (for humans) choices. One twin will wear their hair one way, another a different way. They will vary in weight. If the twins are separated and one is faced with a stressful environmental situation, i.e. starvation, that twin will have different epigenetic marks on their DNA (more on that later).

Genetic variation comes about in 2 ways: mutations and recombination. Recombination happens in sexually reproducing organisms and is, by far, the greater source of variation between individuals. But even a species of bacteria will have variations among individuals because of mutations.

For sexually reproducing organisms, embryonic development can cause variations. What the mother eats or otherwise absorbs and makes it into the bloodstream. For instance, human mothers who smoke or do drugs will change the embryonic development of their babies, which makes those babies dissimilar to babies not exposed.

I mentioned epigenetics. Genes have to be expressed into proteins. The pattern of gene expression — increase in the amount of some proteins and decrease in the amount of other proteins — can be caused by making the gene transcribed into messenger RNA, or stopping the transcription. This is done by enzymes adding a methyl group to cytosine bases in the DNA, or a different enzyme removing existing methyl groups. Changing gene expression can also be done by enzymes that modify the histone proteins that determine how tightly “packaged” the DNA is. More open DNA means more transcription. These changes caused by enzymes are called “epigenetic marks”.

All of these processes are chemical reactions. We do not use the pronoun “who” in referring to proteins or chemical reactions. They are always “it”.

hope it help you

mark as the brainliest