Why is the quadrat method useful for estimating snail populations? do you think it would work for fish populations?

Quadrat method is used for estimating the number of individuals in an area. In this method, a large square area on the ground or water surface is marked, call it an enclave. The number of animals present in this enclave is counted. Then by assuming that the animals are less migratory and are uniformly distributed, their number for a large area is estimated by the use of unitary method of calculation. Example a 4 square feet area has 2 snails, then a 1000 square feet area will have (1000 x 2)/4, i.e, 500 snails in it. Fishes can be counted using this method only if they are confined in a small water body like a lake or a pond. Rivers are flowing so the fishes may move along its length which can give us an underestimate or an overestimate of their numbers. Sea has its depth and huge area, and fishes can be moving randomly in it. Hence this method will not work for river and sea fishes.

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )

a scenario where a cell may be needed to perform a form of endocytosis is when transporting large molecules. a scenario where a cell may be needed to perform a form of exocytosis is when releasing the large molecule from the cell.