The countercurrent heat exchanger that prevents arterial blood from overheating the testes is the pampiniform plexus of veins. The pampiniform plexus helps to regulate testicular temperature, allowing sperm maturation. It surrounds the testicular arteries and works as a countercurrent heat-exchanger system to cool the arterial blood before entering the testes. This is because the sperms can not develop if the testis is at body temperature.
Answer:
Biomagnification also called food web magnification or food web accumulation is the progressive increase in the concentration of contaminants in organisms as the trophic level increases. These unexpectedly large concentrations are the result of DDT biomagnification up the food web.
Explanation:
Answer:
The orchids derive nutrients from the association at very young stages of its life cycle while the fungi obtain water and organic matter
Explanation:
As stated in this question, fungi species belonging to the phylum Basidiomycota form mycorrhizal associations with a flowering plant called orchids. This relationship is a mutualistic one because both participants benefit from the relationship.
In this association, the young orchid plant relies on the mycorrhizal fungi's metabolism to get nutrients needed for its development in form of carbohydrates while the fungi in return gets water (from the roots of the plant) and organic matter.
Edward Jenner inferred that a person who once had small pox cannot have it once again. So something is there in these persons which grows after the initial infection which interferes with the secondary infection resisting it.
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Explanation:</u></h3>
Edward Jenner is called the Father of Vaccination. Jenner noticed that the milkmaids who deal with the cows all the time don't generally suffer from the cowpox or small pox. Then as an Experiment, he took some sample from the pustules of the cow having pox and then cleaned it and injected the sample into a healthy child. Then when everyone of the locality suffered from the same disease, that child remained healthy. So that lead to infer that there are something in the pustule which lead to resist the secondary infection of this disease. So this lead to the invention of vaccines.
Answer:
False
Explanation:
Populations cannot grow exponentially indefinitely.
