Looking at the onion root tip under the microscope you can see large, rectangular cells with visible distinct cell walls surrounding it (cells have a more regular shape because of the wall). Inside the cells, you can notice darkly stained nucleus, large vacuoles at the center and sometimes small granules within the cytoplasm. Looking the onion root tip under the microscope is often the way to observe mitosis. Usually, you cannot see organelles such as mitochondria, ribosomes, rough and smooth endoplasmic reticulum, centrioles and Golgi body as they appear translucent and because are too small to be seen under the light microscope (electron microscope required). Also, chloroplasts are not present in an onion cell because it is not a photosynthetic cell.
Answer:
Answer is A. Vicariance does not require organisms to disperse.
Explanation:
Vicariance occurs when there is a sudden occurrence barrier , such as geographical area barrier that cause the isolation of species of organisms.
Dispersal involves the movement of the organism while vicariance is the change in environment due to sudden occurrence in the area.
In this case, vicariance does not involve movement of organisms while dispersal involves movement of organisms.
UV rays reacting with the O2 molecules
I might be wrong a little but
Hope the helps :)
Answer:
A. Many dinosaurs were present in upper layers of rock strata, but not in lower layers.
Explanation:
In my opinion, this is the best possible answer.
They can sting you if they feel harmed or they can give you honey
