Answer:
The miRNAs act as post-transcriptional silencers, as they are similar to specific mRNAs and regulate their stability and translation. They are small endogenous non-coding ribonucleic acid (RNA) molecules, with about 22 nucleotides, which act as regulators of gene expression in plants and animals, at the post-transcriptional level through the cleavage of a target messenger RNA (mRNA) or repression of translation.
In general, most miRNA genes are transcribed by RNA polymerase II in the nucleus in primary miRNAs (pri-miRNAs). Individually, a pri-miRNA can produce a single miRNA or contain groups of two or more miRNAs that are processed from a common primary transcript. These long pri-miRNA are cleaved by a complex comprising the double-stranded RNAse III enzyme (DROSHA) and its essential cofactor, the binding protein DGCR8 (DiGeorge Syndrome Critical Region 8 protein) in mammals. DROSHA contains two domains of RNAse III, each of which cleaves a strand of the RNA resulting in the precursor microRNA (pre-miRNA) with about 70 base pairs, which contains a double-stranded stretch and a single-stranded loop, forming a structure in clamp. The pre-miRNA is exported to the cytoplasm by the protein exportin-5 (XPO-5), where it is cleaved by DICER1, an RNAse III that assesses the 3 'and 5' ends of the pre-miRNA, generating a mature miRNA with about 22 nucleotides. The processing of pre-miRNA by Dicer promotes the unfolding of the RNA duplex in the form of a clamp. The position in the formation of the clamp can also influence the choice of tape.
Explanation:
Answer:
Genetic, geographic & cultural factors that cause sickle-cell anemia. It is important to note that even genetic diseases are caused by multiple social, environmental and biological factors. This is particularly true in the case of sickle-cell anemia, a genetically inherited blood disorder usually found in people with West African ancestry (PBS 2001).
A) weapons for an evolutionary arms race w/ disease causing organisms
The correct answer is true.
Hope that helps, even though I am late.
Answer:The raw materials required for the process of photosynthesis are carbon dioxide, water and solar energy.
The carbon dioxide present in the atmosphere diffuses into the leaf through stomata.
Water is obtained from the plant roots.
Solar energy is obtained from the sun which gets trapped by the chlorophyll pigment present in the leaves.
Explanation: