What is an important characteristic of an index fossil?

a. it must have been very small.
b. it must not be extinct.
c. it must have lived in a very wide geographic region.
d. it must have lived for a long geologic period of time.

The vaccine in a flu shot contains weakened flu viruses. how does a flu shot work with the immune system? a. it destroys lymphocytes. b. it destroys macrophages. c. it activates macrophages. d. it activates lymphocytes.

Pls need ! in your opinion, what are the limiting factors that might affect the growth or diversity of our ecosystem? respond to this question in claim, evidence, reasoning format. 1. make your claim (i are the limiting factors that might affect the growth or diversity of our 2. follow the claim with 3 pieces of evidence. evidence may be taken from the reading, the videos, previous lessons, or googled answers. site sources, too. 3. use reasoning to explain why you chose your evidence.

In meiosis ii during anaphase ii which structures separated homologous chromosomes or sister chromatids