<span> </span>Stars<span> are formed in clouds of gas and dust, known as nebulae. Nuclear reactions at the centre (or core) of </span>stars<span> provides enough energy to make them shine brightly for many years. The exact lifetime of a </span>star<span> depends very much on its size. I hope that answers your question. :)</span>
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.
Answer:
the radar used in weather forecasting measures the direction and speed, or velocity, of objects such as drops of precipitation.
Explanation:
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Answer:
Cuando dos organismos comparten un ancestro común, su código genético tiene que ser similar. El grado de similitudes determina qué tan recientemente han evolucionado los organismos. ... Cuando dos organismos tienen una anatomía muy similar, podrían haber descendido de un ancestro común
Explanation: