Answer:
Letter A. G-protein coupled receptor
Explanation:
G protein-coupled receptors are a large protein family of transmembrane receptors that pick up extracellular signals and activate signal transduction pathways within the cell. They start this transduction through a chain of events triggered by phosphorylation.
In this question, we may be confused by the options that involve protein kinase, but we have to consider only cell surface receptors, as the request in question.
The process of silk production is known as sericulture. ... Extracting raw silk starts by cultivating the silkworms on mulberry leaves. Once the worms start pupating in their cocoons, these are dissolved in boiling water in order for individual long fibres to be extracted and fed into the spinning reel.
Is A on my opinion, I’m not sure
The major function of the reproductive system is to make sure that the human species<span> survives. It is not necessary for every human being to produce children, but in order to continue our human species, at least some people have to have children. The four main functions of the human reproductive system are: To produce egg and sperm cells, to transport and sustain these cells, to nurture the developing offspring, and to produce hormones.</span>
<span>All of these functions are divided by their primary and secondary, or accessory, reproductive organs. </span>
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Hope this helps and good luck :)</span>