Explanation:
Most minerals can be characterized and classified by their unique physical properties: hardness, luster, color, streak, specific gravity, cleavage, fracture, and tenacity.Crystal form, cleavage, and hardness are determined primarily by the crystal structure at the atomic level. Color and density are determined primarily by the chemical composition.
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:
Daedalus, (Greek: “Skillfully Wrought”) mythical Greek inventor, architect, and sculptor who was said to have built, among other things, the paradigmatic Labyrinth for King Minos of Crete. Icarus and Daedalus, etching by Giovanni David, 1775; in the Metropolitan Museum of Art, New York City.
Identical twins could not be considered as clones for they are different individuals which came from the same egg and sperm. Clones are produced asexually, a copy of another organism. Even though identical twins share the same DNA, they have different qualities as of the other twin which makes them their own unique self.
There are two branches of the autonomic nervous system, namely the sympathetic nervous system and the parasympathetic nervous systems. Both of which regulates bodily functions involuntarily but in different manners. The parasympathetic system is the system primarily activated in "relaxed" states or "rest and digest" states. These include digestion, urination, slowing of heart rate, slowing of respiratory rate, etc. The sympathetic nervous system on the other hand is primarily activated by "flight or flight" response such as rage or fear. These include inhibition of digestion, increase in heart rate and respiratory rate, sweating, etc.
