Daily NEET MCQ- August 12, 2022 - NEET MCQ

Compounds containing more than two benzene rings joined are carcinogenic. They are oxidized in body to form epoxide, which is not excreted readily and finally damage DNA and cause cancer.

If excess of electrophilic reagent is used, substitution reaction may take place in which other hydrogen atoms of benzene ring may also be successively replaced by electrophile. Benzene on treatment with excess of chlorine in the presence of anhydrous AlCl₃ can be chlorinated to hexachlorobenzene.

Sigma bonds are the strongest type of covalent bond, formed by head-on overlapping. In benzene, there are 6(C-C) σ bonds and 6(C-H) σ bonds. Pi bonds are formed by lateral overlapping of atomic orbitals. There are totally 3(C=C) π bonds.

The first law of thermodynamics is based on the conservation of energy. It deals with work done and heat energy supplied or removed from a system. It basically says that energy supplied to a system is conserved.

All the heat supplied will be equal to change in internal energy.
The work done is zero because the container is rigid hence no volume change.
Thus, ΔU = ΔQ – ΔW = 50 + 0 = 50J.

When the disc comes to rest all its kinetic energy will have been converted into internal energy of the system.
The fluid has a heat capacity of 2000J/K which means that for 24J the change in temperature will be 24/2000 = 0.012K.
Given: ΔU = 3.5ΔT
⇒ ΔU = 3.5*0.012
= 0.042J.

Gametophytes are the dominant phase in this life cycle. Sporophytes don’t have free living existence. Spores are haploid in nature and form gametophyte by mitotic division. Zygote acts as Sporophyte that forms spores.

Chlamydomanas exhibits haplontic life cycle i.e. gametophyte are the dominant phase in this life cycle. In this life cycle, there is no independent existence for Sporophyte. Spores produced are haploid and divide mitotically to form Gametophyte.

Sporophyte is the dominant phase. All spermatophytes exhibit diplontic life cycle. Gametophyte depends on the Sporophyte. Sporophyte has independent existence and can perform photosynthesis and hence can prepare their own food.

Generally, most of the algae are haplontic whereas few others are diplontic. Fucus is one such alagae that exhibits diplontic behavior i.e. Sporophyte is the dominant phase in case of fucus.