Answer:
igneous rocks - geosphere
oceans, frozen lakes - hydrosphere
gaseous nitrogen - atmosphere
sea animals, marine plants - biosphere
Explanation:
Hormones glucagon and insulin are produced in the alpha and beta cells respectively in the Islet of Langerhan in the pancreas. They are involved in the negative feedback system of blood glucose regulation in homeostasis.
GLUCAGON: when there is a low blood glucose concentration, the pancreas detect this and alpha cells produce and release glucagon. Glucagon causes the cells of the body to absorb less glucose from the blood. It also inhibits the process of converting glucose into glycogen (glycogenesis) and cause gluconeogenesis (process of converting amino acids/proteins and lipids/fats into glucose) and glycogenolysis (conversion of glycogen to glucose). Finally, glucagon decreases the rate of respiration so less glucose is required.
INSULIN: when blood glucose is high, insulin is released. Insulin binds with cell surface receptors of cells and activates the enzymes attached to the receptor. The enzymes cause a conformational change in the structural proteins that surround glucose transport protein containing vesicles, causing them to move out of the way so the vesicles migrate up to the cell membrane and glucose transport proteins can fuse with it. Thus, more glucose can be taken in by cells. Insulin also cause glycogenesis (converting glucose into glycogen) and inhibits gluconeogenesis and glycogenolysis.
Basically insulin decreases blood glucose concentration (eg. after eating) and glucagon increases it (eg. skipping breakfast in the morning)
The exons of the pre -mRNA contain the protein -coding regions.
Pre mRNA is the first made mRNA transcript and requires undergo many post transcriptional modifications for the formation of a mature mRNA.
The exons are the regions of the pre-mRNA that are found in the mature RNA, after the splicing of introns takes place.
RNA splicing is the process in which the non-coding segments of the RNA, which are known as introns, are removed by the help of small nuclear ribonucleoproteins. These SnRNPs make the spliceosome, which catalyzes the process of splicing.
After the introns are removed by the splicing process, the exons are covalently joined, which forms the mature mRNA.
Learn more about mRNA from here:
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Answer:
a <u>Substitution point</u> mutation changes one base in the genetic code. Only one <u>nucleotide</u> may or may not be affected. An insertion or deletion causes a <u>frameshift</u> mutation which affects all the amino acids following the mutation.
Explanation:
