Questions

RNA is not a lipid among the given options.

A lipid is a substance of biological origin that is soluble in nonpolar solvents. It comprises a group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, and phospholipids.

The receptor molecules, which receive signals from outside the cell, passing the signal to the inside.

In order for a nerve cell, or any cell, to perceive its environment, it needs a sensory apparatus. And for an individual cell, most of that sensation is derived at the cell surface. So, it expresses on its cell surface proteins that span across the membrane.

In the outside world, these proteins can act to receive signals, catching molecules on the outside and then as the molecule passes to the inside of the cell, they can send signals like alarm signals that can tell the cell that a particular molecule is outside.

Hence, here B is the receptor cell.

Economics deals primarily with the concept of Scarcity and choice. Scarcity is the limited availability of a commodity, which may be in demand in the market. Scarcity also includes an individual's lack of resources to buy commodities.

Leading communication app Truecaller has tied up with 'Google' to integrate the tech giant's video calling app Duo within the Truecaller app.