Answer and Explanation:
Example of a food-web:
(1) Algae --> (2) Protozoas --> (3) Krill --> (4) Cephallopods --> (5) Medium sized dolphin --> (6) Large Dolphin
The trophic web is the process of energy transference through a series of organisms, in which every organism feeds on the preceding one and becomes food for the next one.
1) The first link is an autotroph organism or producer, such as a vegetable, that can synthesize organic matter from inorganic matter. In this example, the autotroph organisms are algae, that make use of sunlight and inorganic matter.
The next links are the consumers:
2) Herbivores are primary consumers and feed on producers. In this example, herbivore organisms are protozoan.
3) Krills are the secondary consumers and feed on protozoans.
4) Some species of cephalopods feed on krill, among other species.
5) Specialized Cetaceans such as the Risso´s dolphin, feed especially on cephalopods, as they lack upper teeth and they only have a few teeth in their jaws.
6) The killer whale is a big sized-dolphin and a very important predator. It feeds on many animals, and one of them is the Risso´s dolphin.
Answer:
Its cells have thick, hard walls.
Explanation:
P450scc or cholesterol side chain cleavage enzyme is an enzyme that converts cholesterol into pregnenolone (the precursor for steroids). The kinds of steroid hormones are mineralocorticoids (i.e. aldosterone) glucocorticoids (i.e. cortisol), and sex steroids (i.e. testosterone, estrogen). In the event where P450scc is blocked, then there will be no production of mineralocorticoids, glucocorticoids, and sex steroids. There will be no production of aldosterone, cortisol, estradiol, testosterone, and progesterone. This disease is called Lipoid Congenital Adrenal Hyperplasia.
A cell membrane pump helps human cells to maintain a relatively constant sodium and potassium concentration.
<u>Option: A</u>
<u>Explanation:</u>
Sodium potassium pump is a plasma membrane protein that utilizes energy ATP — Triphosphate Adenosine turning into ADP — Adenosine Diphosphate to deliver intracellular and extracellular sodium (NA+) and potassium (K+) ions sequentially. The purpose of this entire mechanism is to preserve cell equilibrium.
The extracellular medium has a greater concentration of Na while the K concentration of the intracellular fluid is lower. Proteins trap sodium ions in the cytoplasm and pump them out from the cells to preserve cell stability while preserving concentrations. Within the cells proteins inject potassium ions into the cell.
