Answer:
we need the animals and shark in the food change
Explanation:
Answer:
The environment the moths lived in used to be unpolluted. This made dark moths rare. As the area where light moths were found became more polluted, the light moths became less common in the polluted/dark areas. Light Moths began to evolve after not being able to survive in dark forests, they began to get darker and blend in with the polluted area to be safe from predators.
Explanation:
Answer: CHANNEL PROTEINS provide openings in the plasma membrane for substances to flow through without changing structure, and CARRIER PROTEINS allow passage of substances through the plasma membrane after undergoing a subtle change in shape.
Explanation: They are described thus:
A channel protein is a protein that allows the transport of specific substances across a cell membrane.
Carrier proteins are proteins that carry substances from one side of a biological membrane to the other. Many carrier proteins are found in a cell’s membrane, though they may also be found in the membranes of internal organelles such as the mitochondria, chloroplasts, nucleolus, and others.
Directional selection acts against b<span>oth extremes simultaneously in the variation of the trait. This is the most "aggressive" form of selection and only happens in extreme areas.
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Answer:
Methotrexate inhibits the synthesis of DNA, RNA, and protein synthesis of the cells in the experiment.
Explanation:
Methotrexate competitively inhibits the enzyme dihydrofolate reductase (DHFR) which is involved in the synthesis of tetrahydrofolate from the inactive dihydrofolate. The methotrexate blocks the enzyme by binding to its active site thereby preventing further reaction of the dihydrofolate reductase enzyme and dihydrofolate. Tetrahydrofolate is a useful material for the de novo synthesis of thymidine, a nucleoside. And without thymidine, DNA synthesis is hindered. Methotrexate therefore inhibits the synthesis of DNA, RNA, thymidylates and of course protein synthesis.
