I can answer when you say if you are talking about cells or no
Answer
At week 5-6 of gestation, the baby’s heart starts beating.
Explanation
Fertilization occurs in week 3 followed by implantation in week 4.In week 5 the levels of hormones increases with formation of the baby’s heart and circulation system. In week 6, the neutral tube closes followed by development of structures necessary to form eyes and ears. The head of the baby develops at week 7 followed by nose in week 8 and toes in week 9.
<span>They receive more direct sunlight than other regions.</span>
Darwin reasoned that natural selection organisms had adapted to new environments, giving rise to new species. It is a principle of speciation.
<h3>Speciation, natural selection and environment</h3>
Different environmental pressures (e.g. the type of food) lead to different evolutionary pathways in genetically related organisms.
The organisms subject to different environments evolve as a consequence of natural selection in order to adapt (adjust) to their corresponding environments.
In consequence, this process may eventually lead to speciation due to the emergence of reproductive isolation barriers.
Learn more about natural selection here:
brainly.com/question/23929271