Answer:
The correct answer is option - d. Production of primary spermatocytes.
Explanation:
The accessory cells or supporting cells present within the seminiferous tubules of reproductive system termed as the Sertoli cells. They play various roles in the body and reproductive system.
Sertoli cells make blood-testis barrier in adjacent Sertoli cells in the seminiferous tubules. These cells secrete different types of enzymes and hormones such as inhibin which are also secreted by ovary and placenta in females. Sertoli cells produce seminiferous tubular fluid to provide nutrition to the sperm. Apoptotic germ cells are timely eliminated by these cells.
Thus, the correct answer is option D. Production of primary spermatocytes.
Primary succession occurs in essentially lifeless areas—regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier
A,b I think should be the answer
Answer:
<em> It explains how nature works.</em>
Explanation:
A scientific theory can be described as a descriptive explanation of the occurrence of any phenomenon taking place in the natural world. Other statements are not true because a scientific theory is explained best with the help of certain experiments and certain known facts. It might be based on results from many experiments and supported through many known facts. A scientific theory has the capacity to replicate its results when performed again and again.