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.
Answer:
#2 is B #3 is
Explanation:
Plant cells have cell walls around them, and animal cells don't have cell walls. The cell walls give plant cells their boxy shapes. That's nice for plants, because it gives them the ability to grow up and out, where they can get lots of sunlight for making their food.
The nucleus maintains the integrity of genes and controls the activities of the cell by regulating gene expression- the nucleus is, therefore, the control center of the cell.
<span>The stinging organelle of paramecium that assists it in capturing large prey is called trichocyst.
It is used by many organisms as both a defense mechanism, as well as for capturing food. The organism uses this organelle so as to paralyze its prey and later eat it.
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Hydrogen breath test
Milk tolerance test
Small bowel biopsy
Lactose tolerance test
<span>This is speciation. In this process, two distinct species are formed through the intervention of some means such as differing environments or locations. This is done typically as a way of staying evolutionarily competitive in the area in which the species resides. The new species would be the exemplar of that which is best suited to the new conditions.</span>
