Henry the doctor is trying to administer an antidote to his patient. the antidote needs to pass through the membrane of his patient's cell walls. he has 4 versions of the antidote. serum a is in gas form, serum b contains polar organic molecules, serum c contains ions and serum d contains macromolecules. which serum will have the highest rate of diffusion across the patient's cellular membrane and will save the patient's life the fastest?

Arafura file snakes are large, aquatic, non-venomous snakes found in the flood-plains of australian rivers. they feed only on fish found in the rivers. it has been observed that heavy rainfall in the wet season in one year leads to prolonged inundation of the floodplains lasting a year or longer. it has also been observed that these snakes remain in good physical condition after a flood. explain how the file snake population in a region is likely to be affected by the prolonged inundation of a flood-plain.

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