CRQ QUESTION: Variation in a trait is a required condition for natural selection to act on a population for that trait. Assuming a population of organisms started with only one form of a trait, what are two ways variation in the trait could be introduced into the population? Explain your answer.

The diagram below represents a marine food web and a process that can harm the human population. each circle represents an organism and the smaller dots inside them represent a toxic substance. what is being represented and how does it harm the population? the diagram represents biological half-life, in which toxins build up in organisms higher up on the food chain, and this can negatively impact humans who consume the organisms and the toxic substance. the diagram represents biomagnification, in which toxins build up in organisms higher up on the food chain, and this can negatively impact humans who consume the organisms and the toxic substance. the diagram represents the process by which different organisms prey upon each other; this can impact the human population by reducing the number of organisms that do not contain the toxin. the diagram represents the way that toxins are metabolized by living organisms, with those at greater trophic levels able to metabolize more efficiently than those at lower levels. this means that those at higher tropic levels are safer for humans to consume compared to the organisms at lower trophic levels.

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

Where is the nictitating membrane found? a. between the eyelid and the eyeball b. between the retina and the optic nerve c. between the outer and middle ear d. in the organ of corti in the middle ear