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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Answer:
Energy level
Explanation:
Periods in the periodic table are arranged in rows. Each row indicates a new period. For example, period 1 starts at the top and consist of only two elements, Hydrogen (H) and Helium (He).
The periods indicate the highest energy level of the elements that fall in the same row. So as the period increases, the energy level increases.
Answer:
The correct answer is both.
Explanation:
- Each chromosome is made up of a pair of sister chromatids which remain attached to each other at the centromere.
- During DNA replication the DNA duplicates, which means that if initially in the parent cell 'n' chromosomes were present then, after duplication, the number of chromosomes in the cell will be '2n'.
- As mentioned above, each chromosome has a pair of sister chromatids, that is, two chromatids per chromosome. So, 'n' chromosomes will have '2n' chromatids. Hence, '2n' chromosomes will have '4n' chromatids.
- In a parent cell,
- Before duplication, number of chromosome = n, number of chromatid = 2n.
- After duplication, number of chromosome = 2n, number of chromatid = 4n.
- The cell cycle proceeds as, G0, G1, S, G2, M.
- G0 represents the interphase. It occurs before replication or duplication of the chromosomes, which occurs in the S phase.
- So, in G0 phase, the chromosome number is 'n' and chromatid number is '2n'.
Answer:
No animals do not have the ability to use photosynthesis. The cell of an animal lacks the necessary parts to do this. Plants are able to use photosynthesis.
Explanation:
In a tropical forest, there are many tall trees with long leaves that block the sunlight. This top layer is also called the canopy. Since they block the sunlight, there is only a few number of plants that can live on the ground because they don't receive enough sunlight to survive.
