List of practice Questions

$S _{ N } 1$ reaction is basically a solvolysis reaction. Polar protic solvents help the substrate to ionise and by the way get involved in $S _{ N } 1$ reaction.

Open circulatory system is found in most arthropods. Arthropods contain haemolymph which directly bathes internal tissues and organs.

: Noble gases have positive electron affinity. : Noble gases have stable closed shell electronic configuration.

In cockroach respiratory gases directly comes in contact with the various organs of the body. Cockroaches do not have respiratory pigment.

Helium has the highest value of ionisation energy among all the elements known. Helium has the highest value of electron affinity among all the elements known.

Glycine, an amino acid, comes under the category of non-essential amino acids. The fact behind it is that glycine cannot be synthesized in the body.

DNA fingerprinting involves identifying differences in specific regions in DNA sequence. DNA fingerprinting is the basis of paternity testing.

Conductivity of silicon increases by doping it with group-15 elements. Doping means introduction of small amount of impurities like $P, As$ or $Bi$ into the pure crystal.

: Chlorine when solidifies does not have zero entropy even at absolute zero. : Chlorine is a pungent smelling gas and it is difficult to solidify it.

: Calcium carbide on hydrolysis gives ethylene. : Calcium carbide contains $C^{4-}$ anions.

Bond energy and bond dissociation energy have identical value for diatomic molecules. Greater the bond dissociation energy, less reactive is the bond.

Benzene on heating with conc. $H_2SO_4$ gives benzenesulphonic acid which when heated with superheated steam under pressure gives benzene. Sulphonation is a reversible process.

Auditory ossicles are small bones present in the cavity of inner ear. Auditory ossicles maintain the balance of air pressure between two sides of ear drum.

Adrenaline is called an emergency hormone. It acts on the cells of skeletal, cardiac, smooth muscles, blood vessels and fat cells.

A primary amine has higher boiling point than any tertiary amine. A tertiary amine has greater number of $N - H$ bonds for $H$-bonding.

Holandric genes are located

Centre of DNA Fingerprinting and Diagnostics $(CDFD)$ is located at

In a bacterium, the amount of adenine was found to be $18$ percent. Suggest the cytosine base composition from the following

$pBR _{322}$, which is frequently used as a vector for cloning gene in $E$. coli is a/an

The function of nitrogen fixation in Anabaena (cyanobacterium) is performed by

In the blood of an adult man the total content of haemoglobin is roughly

Sinking of zooplankton during the day and rising to the surface at night is an example of

The main function of the white blood cell in the human intestine system is to

Which one of the following is the best stage to observe the shape, size and number of chromosomes in a cell?

Animals take phosphorus from