Scientists estimate that 150-200 species<span> of plant, insect, bird and mammal </span>become extinct<span> every 24 hours.</span>
Answer:
Gonadotropins are polypeptide hormones and are secreted by the anterior pituitary gland.
Explanation:
Hypothalamus releases GnRH i.e gonadotropin releasing hormone which stimulates the anterior pituitary to secrete gonadotrophs such as FSH, ICSH and LH.
FSH (follicle stimulating hormone): In males it stimulates spermatogenesis. In females it stimulates growth of ovarian follicles.
ICSH (Interstitial cell stimulating hormone): In males, secretion of testosterone.
LH (Luteinising hormone): In femalestogether with FSH, it triggers ovulation, stimulates conversion of broken ovarian follicle into corpus luteum.
Answer:
- It has a vital role. It is the only way out of the optic nerve. By this hole optic nerve exits from the eye and goes towards the brain.
- It can be proved by a simple experiment. A paper sheet is taken. Then a cross and a circle are drawn side by side on that paper. Then we will focus on the cross. Then by closing one eye and by bringing the paper slowly towards our face, the circle will be disappeared at a certain point.
Explanation:
The blind spot is a region on the retina where ganglion cells connect with the optic nerve, and the optic nerve and blood vessels leave the eyeball. There are no receptors in this area so nothing can be translated into vision. That's why the blind spot is unable to see things.
<span>The calculated to surface area for red blood cells by Gorter and Grendel found to be 36u2.
The surface area that would be covered once they spread across the surface of the water is 72u2.
If they spread across the surface area will double. This is because the lipid bilayer with phospholipid the head faces the water on each surface of the membrane.
It clearly shows that there must be more to membranes than lipid bilayer because membranes grew and the surface tension of membranes is much lower than those of pure lipid structures.</span>
<span>The cell has 1% concentration of the salt. The external environment is highly concentrated with 25% saline solution. This will lead to release of water outside the cell, by passive diffusion from a region of high conentration of solvent to lower concentration. Thus, the cell will shrink.</span>