Living in a certain place, eating certain things, and being active at certain times all define an organism's ecological niche. For example, bats in central Texas are nocturnal and eat nocturnal flying insects. Having an ecological niche is critical to the survival of a species. Sudden changes in climate or major geological events can cause mass extinction of organisms in an area, which creates vacancies in ecological niches. What happens then?
A. other organisms adapt, evolve, and compete to fill them
B. The environment evolves in order to attract a variety of replacement organisms.
C. With no life to fill them the niches simply disappear.
D. The niches remain empty until another geological event reverses the damage.

Awoman whose sister tested positive for a specific mutation in the brca1 gene, which increases the risk for breast and ovarian cancer, is found not to have that mutation but does have a mutation of unknown significance near the known mutation site. how should this woman be counseled? select one: a. she should be informed that her risk for breast cancer is greater than the general population but not as great as her sister’s risk. b. she should be informed that because she does not have the mutation, her risk for breast cancer is not greater than that of the general population. c. she should be informed of her gene mutation status and be presented with all the available prophylaxis options and reconstruction options. d. she should be informed that she does not have the specific mutation but that because another mutation is present she should be vigilant about screening

Which direction does the energy flow in this energy pyramid ?

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