The answer is spicules. These
sharp-pointed structures are formed from calcium carbonate skeleton of
the organisms. They can also be formed from silica. They can be big (megascleres),
or microscopic (microscleres). Also dependent on the number of axis on the spicules, they are classified as monoaxon,
triaxon or polyaxon.
Answer:
organisms that have more favorable traits tend to leave more offspring ... improved fitness of certain individuals in the population that allows for survival and reproduction. ... Based on H-W conditions, five major causes of evolution: ... factors that prevent organisms of two species from producing vigorous, fertile offspring
Explanation:
