While playing soccer, allen falls and scrapes his knee. over time, the wound on his knee heals. how does this happen?
select one:
cells from blood flood the damaged area and become different cells.

cells in the damaged parts become larger and eventually become large enough to cover the wound.

cells in the damaged parts divide and produce more cells by undergoing mitosis.
cells grow in different parts of the body and then arrive at the damaged part through blood.

Which organelle breaks down sugar molecules that supply energy to the cell ?

Juan and carol were studying invertebrates in biology. they knew that segmented or earth worms preferred a dark, moist habitat. during this lab, they would be investigating the responses of organisms called planaria or dugesia tigrina. these were simple flatworms that still had a one-way digestive system and a very simple nervous system. juan and carol placed the planaria in a petri dish containing cool, distilled water that was partially covered with black paper. they shined a light on the dish. next, they removed the paper and placed a small amount of chicken liver at one end of the dish. they added a few large salt crystals to the water. finally, they added drops of hot water to the cool water in the petri dish. their results can be seen in the data table. according to their experiment, all but one conclusion is valid.

The greenhouse effect a. something that has occurred for millions of years b. an unnatural phenomenon caused by humans that maintains earths temperature range. c. the results of the differences in the angle of the suns rays d. an unnatural phenomenon that causes heat energy to be radiated back into the atmosphere