What are the similarities between the two types of cells (onion and whitefish)?

During mitosis the animal cell will have visible centrioles where the plant cell will not. In thin section slides you will also see that the onion cells are all dividing along the same axis while in the whitefish embryos the plane of division appears to be random.

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.