Explanation:
Gram staining is a widely used technique designed to distinguish between the bacteria on the basis of the composition of the cell wall of the bacteria.
The basis of differentiation is the color of the bacteria they attain after staining technique is performed that is gram-positive bacteria remain deep blue in color while gram-negative bacteria appear pinkish-red in color.
If the culture of the bacteria on which the test to be performed is of more age that is more than 24 hours of age then the bacteria cells lose their ability to retain the stain mainly the gram-positive bacteria. Also, the culture gets damaged after 24 hours.
Thus, fresh cultures are used for staining.
The light intensity decreases with increasing depth of the ocean water. This leads to the division of the ocean into three major zones, sunlight zone, twilight zone, and deep sea zone. The autotrophs like the phytoplankton live in the sunlight zone and perform photosynthesis using sunlight. Various fishes that eat planktons also live in the sunlight zone. The twilight zone is inhabited by various predators like the octopus, sharks and dolphins. Here the pressure of water also is greater. In the deep sea zone, no light is present. Fishes like the angler fish and other bio-luminescent organisms live here. This zone also contains chemotrophs as the producer of food. The pressure of water at this zone is the greatest which is not bearable by the organisms living above it. Thus in this manner light and depth determine the distribution of various organisms in the ocean.
H2O is acquired by osmosis in the plants cells, and or through the stomata. CO2 is obtained in the way of the Stomata.
The solution that is used as a preservative for a blood sample is a solution of 0.1 mg sodium citrate plus 0.1 mg mercuric chloride. Option A
<h3>How is blood preserved?</h3>
Many times, it is important to transport a blood sample from one point to another. In such cases, it becomes important to add a preservative to the blood sample so that it does not coagulate.
The solution that is used as a preservative for a blood sample is a solution of 0.1 mg sodium citrate plus 0.1 mg mercuric chloride. Option A
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