Answer is A. A population becomes separated by environmental factors into two groups that do not reproduce with one another.
When a population of a species become geographically separated then gene flow between them stops. Over a period of time, the population may become genetically different in response to the natural selection due to different environments. Selection and genetic drift will act differently on these two separated populations. This will results into two separate species. This type of speciation is called allopatric speciation.
Answer:
James Watson and Francis Crick with their DNA model at the Cavendish Laboratories in 1953.
Explanation:
Answer:
A
Explanation:
Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. The size and coding capacity of the mitochondrial DNA varies considerably in different organisms, and encodes rRNAs, tRNAs and essential mitochondrial proteins.