Doctors do not administer vaccinations to people who are too sick. which best explains why? a. the weakened or dead form of the pathogen may not have any effect on sick people. b. the weakened or dead form of the pathogen may have a fatal effect when it is combined with medication that the sick people are taking. c. the digestive systems of sick people may be negatively affected by the weakened or dead pathogen. d. the white blood cells of sick people may not be able to efficiently handle the weakened or dead form of the pathogen.

Elements and compounds are pure substances that cannot be broken down physically into a simpler substance. a physical change doesn’t break the bonds between atoms of a substance or form new ones. compounds can be broken down by a chemical change. a chemical change breaks chemical bonds and/or forms new ones between atoms of a substance. what simple substance would a compound break into? the basic elements that make it up! for example, if you passed a very strong electric current through water you’d break the chemical bonds in water and be left with oxygen and hydrogen. which of the following is an example of a chemical change? a separating water into different glasses b breaking frozen ice cubes with a hammer c running an electric current through water d boiling water to evaporate it on a stove

There are specialized producers that live in warm water vents deep in the ocean. these producers do not per-form from photosynthesis, but instead perform a similar process with iron and other chemicals. why do you think these producers use this process instead of photosynthesis?

Which of the following is a true statement? question 8 options: populations can't evolve, only individual organisms. individuals have adaptations that can change over time. individuals have traits that may or may not make them successful at reproduction. individuals evolve to have adaptations.