List of practice Questions

Classification is necessary to study all living organisms. In classification, individuals are grouped into categories.

Closed circulatory system is less efficient than open circulatory system. The blood flow is slow in closed circulatory system than in open circulatory system.

$CO_{2}$ is a gas at room temperature while $SiO_{2}$ is a crystalline solid. $SiO_{2}$ is a network of silicon and oxygen atoms joined by multiple bonds.

Catenation tendency is weaker in nitrogen. Nitrogen exists as diatomic gas.

$CH_{2} = C H ??H_{2}??$ is an example of allyl halides. These are the compounds in which the halogen atom is bonded to an $sp^{2}$ hybridised carbon atom.

Chances of survival of young ones is greater in viviparous organisms. All mammals are viviparous.

Carbon atom is tetravalent though it has two unpaired electrons. Carbon has unique ability to form $p\pi-p\pi$ multiple bonds with itself like $C=C, C\equiv C$.

Carbon monoxide is a poisonous gas. Carbon monoxide combines with haemoglobin to form carboxy-haemoglobin which prevents absorption of oxygen by it.

Both apical meristem and intercalary meristem are primary meristems. Both of these meristems appear early in life of a plant and help in the formation of the primary plant body.

: Bulk modulus if elasticity (K) represents incompressibility of the material. : Bulk modulus of elasticity is proportional to change in pressure.

Buna-$S$ is a copolymer. Buna-$S$ is formed by condensation reaction between two different monomers.

Caecum is a small blind sac which hosts some symbiotic microorganisms Escherichia coli in return produces vitamin $B_{12}$, vitamin $K$, thiamine and riboflavin

Bharat stage $IV$ emission norms have been in place since April $2010$, for $4$ wheelers in $13$ mega cities of India. Green muffler scheme refers to the plantation of trees and shrubs along road sides and is effective to control noise pollution only.

Biofertilisers are preferred to chemical fertilisers Chemical fertilisers are generally more expensive and hazardous to environment

Bone has very hard matrix whereas cartilage has pliable matrix. Bone has calcium salts in its matrix whereas cartilage has chondroitin salts in its matrix.

Boron is metalloid Boron shows metallic nature.

Balmer series lies in the visible region of electromagnetic spectrum. $\frac {1}{?}=R \bigg [\frac {1}{2^2}- \frac {1}{n^2} \bigg ],$ where $ n=3,4,5 $

Bell shaped age pyramid represents a stable population. In a stable population, proportion of individuals in reproductive age group is higher than the individuals in pre-reproductive age group.

: Atom as a whole is electrically neutral. : Atom contains equal amount of positive and negative charges.

Atomic number of the element ununtrium is 113. According to $IUPAC$ system of nomenclature, the numerical roots for $1,1$ and $3$ are un, un and tri respectively.

$ATP$ acts as the energy currency of the cell. $ATP$ can be broken down to release energy wherever and whenever energy needs to be utilised.

Auxin was isolated by $F$.$W$. Went from the tips of coleoptiles of wheat seedlings. Ethylene delays the senescence.

Asexual reproduction involves formation of clones of an organism. Clones are morphologically and genetically similar individuals.

At fovea, the visual acuity is the greatest The fovea is a thick area of the retina where both rods and cones are present

At high altitudes, liquids boil at lower temperatures in comparison to that at sea level. At high altitudes, atmospheric pressure is low.