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.
Just check if it has all the characteristics of life.
1. Is it made of cells?
2. Does it metabolize?
3. Does it keep internal conditions stable? (Homeostasis)
4. Does it have organs?
5. Can it reproduce?
6. Does it grow/develope?
7. And does it respond to stimuli (poke a bug, it moves. flower grows towards the sun.)
If all of these are Yes, your specimen is in fact, living.
Answer:
Estuaries filter out sediments and pollutants from rivers and streams before they flow into the ocean, providing cleaner waters for humans and marine life.
An economy – householdand is an area of the production, distribution and trade, as well as consumption of goods and services by different agents. Mark as brainliest
