Which describes the double-loop system but not the single-loop system?

heart and circulatory system

Explanation:

It has 2 routes of circulation, one to the body and one to the lungs

a single loop has a pump that forces blood around those in one direction where as, a double loop has a double loop pump circulatory system.

Explanation:

Quizlet biology

succession returns a disturbed

ecosystem to a more stable state. this is also classified into two (2) types:

primary succession and secondary succession. the primary succession arises when

a new land is transformed and a bare rock has been exposed providing an environment

that can be occupied for the first time. while, secondary succession occurs

when a previously occupied environment was disturbed that kills much of all its

community

explanation:

sex cells are usually half's then they find another half and make a fertilize egg