Natural selection act directly upon <u>Alleles</u>
Explanation:
Genes, such as that of fur color, have many variants called alleles. Natural selection act on the alleles and chooses the best fit for an environment and eliminates the disadvantageous ones from the population over generations. Mutations are a rare occurrence that increases the number of allelic variants of a genes on which natural selection can act upon.
As the heart beats, it pumps blood through a system of blood vessels, called the circulatory system. The vessels are elastic, muscular tubes that carry blood to every part of the body.
Blood is essential. In addition to carrying oxygen from the lungs and nutrients to your body's tissues, it also takes the body's waste, including carbon dioxide, away from the tissues. This is necessary to sustain life and promote the health of all the body's tissues.
B - energy flow from one tropic level to the next
Answer:
Ethylene
Explanation:
Ethylene is a hormone required to trigger fruit ripening, and it can be blocked by using synthetic compounds, such as 1-methyl-cyclo-propene (1-MCP).
Answer:
Glycolysis and Krebs cycle.
Explanation:
During cellular respiration, the first carbondioxide gas is generated during glycolysis while the remaining carbons are given off as carbondioxide during Krebs cycle. During the process of glycolysis in cellular respiration, glucose is oxidized forming carbondioxide and water whereas during the Krebs cycle, the two carbon atoms of acetyl-CoA are released and each turns into a carbondioxide molecule.