NEET Test 164

Endocytosis is the process in which the ingestion of material by the cells is done through the plasma membrane or we can say that it is the process of actively transporting molecules into the cell by engulfing it with its membrane.

Two main types of endocytosis are distinguished on the basis of the size of the endocytic vesicles formed. One type is called phagocytosis (“cellular eating”), which involves the ingestion of large particles, such as microorganisms or dead cells via large vesicles called phagosomes (generally >250 nm in diameter). The other type is pinocytosis (“cellular drinking”), which involves the ingestion of fluid and solutes via small pinocytic vesicles (about 100 nm in diameter).

The edible part of most fruits is the actual ovary, but in apples and pears only the outer hypanthium layer is eaten. The fruit which develops from the ovary is called true fruit. Most of the fruits are true fruits. If any other floral part takes part in fruit formation, it is called false fruit (pseudocarp) e.g., Apple, Pear.

The purpose of using Mn²⁺ (divalent cations) in Polymerase Chain Reaction (PCR) instead of Mg²⁺ to increase the error rate.

Sucrose is a non-reducing sugar because the two monosaccharide units are held together by a glycosidic linkage between C₁ of α-glucose and C₂ of β-fructose.

Glucose undergoes an oxidation reaction to give gluconic acid in the presence of bromine water solution. Bromine water is a mild oxidizing agent that selectively oxidizes aldehyde to carboxylic acid only.

Natural glucose is dextro-rotatory (clockwise) and this glucose is also known as dextrose. Thus, it rotates the plane-polarized light to the right.

Bromine water is not capable of oxidizing fructose (ketone).

Most acidic hydrogen is present in

as two strong electron-withdrawing groups CO are present around the active methyline group.

The structure of (CH₃CO)₃CH:

Alkyl halides have polar carbon-halogen bonds. There is a significant difference in electronegativity between carbon and halogen.

Water is a polar solvent. It dissolves polar solute. This is based on the principle of like-dissolves like. Non polar solvents dissolve nonpolar solute. Based on this principle, alkyl halides should be miscible with water. But however, in reality, alkyl halides are immiscible in water.

Water forms intermolecular hydrogen bonds which are strong interactions. When alkyl halides are added to water, the strength of interaction between an alkyl halide molecule and a water molecule is weaker than the strength of a hydrogen bond between two water molecules. Thus, alkyl halides can neither form hydrogen bonds nor can they break the hydrogen bonds of water.

Thus, alkyl halides are immiscible in water though they are polar because they cannot form hydrogen bonds with water.

Potassium superoxide (KO₂) is used in oxygen cylinders in space and submarines because it acts as an oxygen generator. It absorbs the CO₂ and increases the O₂ content.

This can be shown by the equation:

4KO₂ + 2CO₂ → 2 K₂CO₃ + 3O₂

As we can see in the equation, CO₂ is getting absorbed by KO₂ and oxygen is produced.

In places like space or inside submarines underwater, the level of oxygen is very low and oxygen cylinders are used.

Increasing the efficiency of these oxygen cylinders will help the cylinder to last longer.

The net force on the rocket is zero.

Because force due to the earth and force due to the moon is the same but in opposite direction.

(A) is correct

(B) for equilibrium r_f = r_b ⇒ (B) is correct

(C) at equilibrium the value of parameters become constant of a given temperature and not equal ⇒ (C) is incorrect

(D) for a given solid solute and a liquid solvent solubility depends upon temperature only ⇒(D) is correct