Answer:
Two ureters.
These narrow tubes carry urine from the kidneys to the bladder. Muscles in the ureter walls continually tighten and relax forcing urine downward, away from the kidneys. If urine backs up, or is allowed to stand still, a kidney infection can develop.
Explanation:
He first divided all living organisms in 2 groups
Animal or Plant
He then put these into subgroups
Animal subgroups: land, water, air
Plant subgroups, small medium or large
Not a very specific approach to taxonomy but it was used for well over 100 years
Answer:
to indicate the smallest unit of a repeating substance
Explanation:
Photosystems 1 and 2 are here
