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)
(B) 25% GG, 50% Gg, and 25% gg
<u>Explanation:</u>
Given:
Green is dominant and is coded by G
Albino is recessive and is coded by g
Two corn plants that are heterozygous for color are crossed.
The heterozygous condition of the plant would be Gg.
The cross is shown in the table attached.
According to the punnett square drawn,
The genotypic ratio is 1 : 2 : 1 (GG : Gg : gg)
= 25% GG , 50% Gg , 25% gg
Phenotypic ratio = 3 : 1 ( green : albino)
= 75% green, 25% albino
<span>Coral bleaching. The name is apt, as coral affected by this process will lose their vibrant color and become white, which is the color of the calcium carbonate substrate that the coral polyps build around themselves. Coral bleaching can be reversed, but only if ideal conditions return quickly.</span>
