<span>Variations in asexual organisms are rather rare since they occur as a result of mistake of mitosis during DNA copying. On the other hand, variations in sexual organisms are a result of fusion of two different gametes that carry different traits. Thus, the offspring carries characteristics of both parents, resulting in greater genetic variation within the next generation. Consequently, sexual organism obtain greater genetic variation than asexuallt reproducing species.</span>
Answer:
The correct option is A
Countercurrent multiplication is the process whereby energy is used to generate an osmotic gradient in which water is reabsorbed from the tubular fluid to produced concentrated urine.
Explanation:
Countercurrent multiplication moves sodium chloride from tubular fluid into interstitial space deep within the kidneys. The concurrent multiplication process build up osmotic gradient interstitial fluid in a single effect. Here, sodium chloride is driven by active transport out of the tubular fluid in the thick ascending limb into the interstitial fluid, which becomes hyperosmotic. This result to water moving passively down its concentration gradient out of the tubular fluid in the descending limb into the interstitial space to a point where it attains a state of equilibrium.
Therefore,the correct option is A, where the ions leaves the ascending limb to make water comes out of descending limb.
<span>Pulmonary vein
Pulmonary circulation is the movement of blood starting from the heart, where deoxygenated, or carbon dioxide-filled, blood leaves from the right ventricle and through the pulmonary valve, then into the left and right pulmonary arteries and arrives at the lungs. During the process of respiration, the carbon dioxide is released and oxygen is added to the blood. </span>
I believe it would be to calculate the amount of C-14 atoms left. scientists began to find out how long an object has been decaying, this has to do with half lifes etc. and how long a specific mineral/elements half life is. they use this to calculate how old it is (not an exact age but it's very accurate.)