Cacti with very few spines tend to be eaten by animals, and cacti with many spines tend to be preferred by parasitic insects. This causes cacti with an average number of spines to be preferred. How would you explain this

c is the correct answer!

in addition to being able to metabolize, grow, digest food, and excrete wastes, what other functions must an organism perform if it is to survive? survival also depends on the ability to maintain one's boundaries, to move, to respond to stimuli, and to reproduce. oxygen is a survival need.

the cell is the smallest structural and functional unit of living organisms, which can exist on its own. therefore, it is sometimes called the building block of life. some organisms, such as bacteria or yeast, are unicellular—consisting only of a single cell—while others, for instance, mammalians, are multicellular.