Answer:
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.
Explanation:
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Compressed is the first blank and older is the second one
Answer:
compare two body wave
Explanation:
compare one on one body wave
The answer relates to the medium in which the sensed molecules travel. On land, animals detect a scent through organic molecules transported in the air. Land animals will experience a taste sensation by grasping an object using their mouth. Here, the organic molecules providing the sensation are transported by saliva or organic fluids of the object. So on land, there is a clear distinction between molecules transported in the wind and those that can be tasted. Water is a much more dense medium than air, and can carry small and large organic molecules, unlike air. Therefore, aquatic animals have little need for olfactory organs as all molecules can be 'tasted' from the water.
