Cell division is the process essential for growth and repair in multi-cellular organisms.
Injury to the tissue can activate surrounding cells to undergo cell division with the help of mitogens. Mitogens are the chemical substances which help in escalating mitotic divisions in the cells.
They act by activating the signal-transduction pathway which involve mitogen-activated protein kinase (MAPK).
Other possible manner could be the loss of density which could lead to the inactivation of contact inhibition. As there is a loss of cells during the injury, it makes an empty space which could also trigger or activate surrounding cell to start cell division.
In addition, at injury site the flow of blood also increases to transport various nutrients, clotting factors, growth factors etc. These increased nutrition and growth factors also speed up the process of mitosis.
Lethal alleles cause the death of an organism prenatal or after the birth. Lethal alleles are usually a consequence of a mutation and they can be recessive, dominant or conditional. Since the lethal dominant alleles are harmful whether they are carried in homozygous (e.g.AA) or heterozygous (e.g.Aa) form, a strong selection against them is present and thus these alleles are much more rare.
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Explanation:</h2><h2 /><h3>There is empirical evidence that environmental injustice is caused by many factors, including discriminatory siting, misguided regulatory policy, unequal regulation enforcement, and unequal political power.</h3>
The best summary of the process of natural selection will be provided bythe option D that is genes are always passed from parent to offspring . Hence , out four inheritance is one of the option in the given question that is gene are passed from parent to offspring .
