Channel proteins help large molecules pass through the cell membrane.
Answer:
Pandemics occur for two reasons. The first is a change in the infectious agent and the second is in human patterns. Both involve exposing people to agents they don’t have resistance to. Diseases like SARS, avian flu, and the famous Spanish flu all involved a mutation in the virus that resulted in a new disease that no one had resistance too. Examples of the second are when new groups of humans make contact, like small pox amongst native Americans, and possibly the black death.
Explanation:
Answer:
A. Cell wall and chloroplast
B. Nucleus (the dark grey circle)
Explanation:
S phase
M phase (mitosis) is usually followed by cytokinesis. S phase is the period during which DNA replication occurs. The cell grows (more...) The duration of these cell cycle phases varies considerably in different kinds of cells.
