Answer:
A. Cell membrane, DNA, ribosomes
Explanation:
I'm not so sure, sorry if i'm wrong ):
B - When many individuals of the same species are available for mating.
And
C - When the individuals live in a stable environment in which they thrive.
Answer:
1.) stromatolites
2.) photosynthesis
3.) Ordovician
4.) Cambrian
5.) oxygen
6.) As Earth cooled, carbon dioxide dissolved in the early ocean. Cyanobacteria consumed carbon dioxide and converted it to oxygen. Methane was removed from the atmosphere as oxygen was produced, eventually leading to the Cambrian Explosion.
7.) Metabolic processes that use oxygen produce more energy than anaerobic metabolism. Simple diffusion of oxygen would limit the size of a multicellular eukaryote, but animals evolved ways to transport oxygen to their tissues, which permitted an increase in size.
Explanation:
From Penn
I think the answer is B, the interpretation of specific events as threatening or challenging. According to Hans Selye stress is a body's nonspecific response to any demand made on it, physical arousal to events seen as threatening, and mental arousal to events seen as challenging. However, there are effective strategies to cope with stress which include a sense of humor, relaxation, social skills, and social support.