A sarcomere is the basic contractile unit of muscle fiber. Each sarcomere is composed of two main protein filaments—actin and myosin—which are the active structures responsible for muscular contraction. The most popular model that describes muscular contraction is called the sliding filament theory.
Answer:
Nephrons in birds, mammals, and reptiles are all extremely similar, more so than other structures in the bodies of different species, solidifying the relatedness through similarity.
Explanation:
Birds can be said to have "mammal-like" nephrons from the number of loops and overall structure of their kidneys, which, although they look very different, serve the same purpose and do it in largely the same way. Reptiles also have mammal-like nephrons, and it can be assumed that this evolutionary trait was kept because the specific structure of the nephrons is generally the most efficient.
Answer:
Burning of woods has a negative impact on the climate.
Explanation:
Burning of woods for heating has a negative impact on our climate because it releases carbondioxide gas which is a greenhouse gas that trapped the reflected solar radiation and leads to global warming. We have to used alternative methods for heating such as electric heater instead of burning of wood which produce no pollution and can fulfill the requirement of heating so from the above discussion we can say that the activity has a negative impact on the environment.
The stomach is an example of an organ. The mitochondria N is an example of an organelle. The mushroom and the bacterium are examples of organisms.
Answer:
Option B) functions to increase sodium reabsorption.
Explanation:
Aldosterone is an hormone secreted by the cortex of the adrenal gland. The adrenal gland is situated at the superior poles of the right and left kidneys.
Aldosterone regulates sodium homeostasis and as such helps to control blood volume and blood pressure.
Aldosterone is secreted in response to decreased blood pressure (hypotension) to increase sodium reabsorption from urine, sweat, and the gut. Also excessive aldosterone levels (too high sodium) can lead to high blood pressure (hypertension).