Gene X always produces the same mRNA (one splice form) and the same protein in all cells in which it is expressed. The same amounts of gene X mRNA and protein are present in brain, kidney, and heart cells. However, the activity associated with the protein is present only in the heart. Which of the following are possible explanations? a. A splicing factor necessary for removing all of the primary transcript's introns is present only in the heart.
b. A splicing factor necessary for removing all of the primary transcript's introns is present only in the brain and kidney.
c. Protein X is phosphorylated only in the heart.
d. Protein X is phosphorylated only in the brain and kidney.

There are two explanations for this phenomenon: phosphorylation of the protein X in the heart activates its function (Option C) or phosphorylation of the protein X in the kidney and the brain deactivates its function (Option D). Therefore, both Option C and Option D are correct.

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answer: tributaries flow into rivers.

wetland is a biome that develops when the water gets accumulated in a land exhibiting a huge depression. these form either seasonally or permanently. the water in the wetland comes from rivers, lakes, ocean, flood, rain or other sources. the wetlands includes mangroves, marshes and peatland.

tributaries flow into the rivers develops a wetland because such water will get deposited in the depression and will restrict the original flow of tributary water. hence, water with low drainage current combines with the river water.

the answer is: trichonympha lives in the gut of termites and digests cellulose eaten by the termite.

this is an example of a symbiotic association of a protozoan with its mode of association.

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