The best answer is D.
In active transport, molecules move against a concentration gradient from areas of lower concentration to areas of higher concentration. This happens a lot in neurons. The membrane proteins are constantly pumping ions in and out to get the membrane of the neuron ready to transmit electrical impulses.
In active transport , energy is required to move molecules across the cell membrane. Carrier proteins are needed for this e.g. proteins of the GLUT family which transport glucose molecules across the cell membrane. Carrier proteins are very specific. GLUT proteins will only move glucose molecules and not sodium or calcium. There are hundreds of types of carrier proteins.
<span>Processes that increase the density of seawater include evaporation and sea ice formation. The density of seawater primarily depends on two factors, temperature and its salinity. When temperature is decreased and salinity is increased, the density increases. Sea ice formation lowers the seawater's temperature, while evaporation increases the salinity.</span>
Answer:alveoli; lactiferous ducts
Explanation:
The base pairs are put into different orders and these orders code for different amino acids.
Answer: we can make observations directly by seeing, feeling, hearing, and smelling, but we can also extend and refine our basic senses with tools: thermometers, microscopes, telescopes, radar, radiation sensors, X-ray crystallography, mass spectroscopy, etc. And these tools do a better job of observing than we can!
