Answer:
Phytoplanktons are microscopic creatures that are primary producers of oceans. Phytoplanktons take carbon dioxide from atmosphere to make their food and then they are eaten by some other animals of oceans.
Phytoplanktons are present in huge numbers in oceans and have a great contribution to the carbon cycle because it is responsible for the transfer of carbon dioxide from the atmosphere to the oceans.
Most of the carbon is released through combustion by animals that eat phytoplanktons but some accumulate in the ocean floor because some dead phytoplanktons settles down in the ocean.
This is only explanation. What are the questions for it?
The correction is B.
The respiratory system is the one that is responsible for transportation of oxygen from the outside to the lungs and the reverse transportation of carbon dioxide from the body to the atmosphere. The muscular system is responsible for the contraction of muscles around the air passages during respiration. These two systems are negatively affected in asthma patients during respiration.
Operons are gene regulatory mechanisms that involve promoting and repressing genes that are involved in the metabolism of organic substances (i.e. sugars). Living organisms have the innate ability to metabolize glucose as the main source of energy. Although, in the absence of glucose, the organism must "learn" to use sugars other than glucose (such as lactose) in order to survive.
For instance, in the <em>lac </em>operon:
In the absence of glucose, various regulatory proteins promote the transcription of the gene related to the metabolism of lactose. This will ultimately lead to the production of the enzyme beta lactosidase which will enable the organism to use lactose as energy in the absence of glucose. This will therefore increase the chances of the organism for survival and will be naturally selected for evolution.
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