Answer:
(a) an aquaporin
Explanation:
An aquaporin is a water channel which forms a pore in the cell membrane and facilitates the movement of water. Aquaporin is an integral membrane protein (permanently attached to the membrane) that enables the in and out flow of the water. This channel also prevents the passage of ions and other solutes, so it cannot change the voltage. There are four types of aquaporins, and they are mostly found in the kidney with the function of water reabsorption.
Answer:
Water, carbon dioxide, and oxygen are among the few simple molecules that can cross the cell membrane by diffusion (or a type of diffusion known as osmosis ). Diffusion is one principle method of movement of substances within cells, as well as the method for essential small molecules to cross the cell membrane.
Explanation:
Answer:
The correct answer is option D, that is, 27.
Explanation:
27 three-nucleotide codons would be possible when polynucleotide phosphorylase is supplemented to a solution of GTP, ATP, and UTP. As there are three nucleotides available, that is, guanine, adenine, and uracil and each codon comprise three nucleotides, thus, there would be a probability of (3)^3 codons, that is, 27.
