Answer:
a human being
Explanation:
Selective breeding -
It is the method of selection , where the human develops the new organism having some characteristics which they desire , is known as selective breeding .
In this case , the humans select two parents to mate in order to produce the offspring with the desirable traits .
hence ,
Humans are responsible of the process of selective breeding .
Answer:
Spermatogenesis is stimulated by FSH acting on sertoli cells.
Explanation:
Spermatogenesis is the process by which spermatozoa grow and develop from germ cells into mature form. There are many hormones that are involved in this process and one of them is FSH (Follicle Stimulating Hormone). Another factor that play a vital role in the process are sertoli cells.
The FSH stimulates sertoli cells to release androgen-binding protein into the lumen portion of seminiferous tubules. The sertoli cells are the epithelial supporting cells that are located inside the seminiferous tubules. The sertoli cells are responsible for keeping the germ cells nourished and for extracting excess cytoplasm from newly formed spermatozoa cells just before they are released into the lumen of the seminiferous tublules.
The correct answer is contrast
You put together dissimilar items to create a contrast. The dissimilarity is often so high that the objects are actually complete opposites.
Out of the following given choices;
(1) an increase in the number of clams
(2) a decrease in the number of water plants
(3) an increase in the number of crabs
(4) a decrease in the number of crayfish
The answer is D. Crayfish are are freshwater crustaceans resembling small
lobsters. Clams and crabs are found in marine waters. Most crayfish cannot
tolerate polluted water. Crayfish feed on animals and plants, either living or
decomposing, and detritus, therefore a decrease in small invertebrates in the river
would decrease their food source thence
consequently affect their numbers.
