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.
Reproduction
Additional info-
https://courses.lumenlearning.com/biology2xmaster/chapter/classification-of-fungi/
Mitochondrion a singular word for mitochondria is a "powerhouse" organelle of the cell.
<span>Mitochondrion
is an important organelle in most living organisms because it is where
biochemical processes of living organisms such as respiration takes
place. The mitochondrion has a smooth outer membrane but a larger inner
membrane. The inner membrane is about 70% protein and is very convoluted
because that can even fit inside the outer membrane. Mitochondrion is
the carrier of the Kreb's cycle in the matrix and it is responsible for
the transfer of electron chain found in the cristae of the inner
membrane.</span>
I believe that on the Naive B-cell the antibodies exist as transmembrane proteins. A naive b-cell is a type of b-cell that has not been exposed to an antigen. When exposed it becomes either a memory B cell or a plasma cell that secrete antibodies specific to the antigen that was originally bound.
