the models of the solar system were the couple of planets and a very big star. AKA the sun
Answer:
d) passage of a solute against its concentration gradient
Explanation:
When a solute is transported against its concentration gradient, the cells use metabolic energy. To move a substance from the region of its lower concentration to that of its higher concentration, the energy of ATP hydrolysis is utilized. These types of transport mechanisms are called active transports. If ATP hydrolysis is inhibited in a cell, it would not be able to perform the uphill movement of solutes due to the lack of any source of energy to drive the process.
Tryptophan self-controls its synthesis. If we have a large amount of tryptophan in the sense that it exceeds, tryptophan would act as a co-repressor which prevents synthesis of more enzymes for its production. Hope this answers the question.
<span>Answer: Cellular differentiation is responsible for one daughter cell becoming a sieve tube whereas the other becomes a companion cell. Cell differentiation occurs as different genes are switched on and off.
Hope this answer helps!</span>
