Daily NEET MCQ- March 16, 2022 - NEET MCQ

There are 7 base units for measuring physical quantities according to the SI system. They are kilogram (kg) for mass, second (s) for time, kelvin (K) for temperature, ampere (A) for electric current, mole (mol) for the amount of a substance, candela (cd) for luminous intensity, and meter (m) for distance.

One Newton equals to 100000 Dynes, hence 5 N equal to 500000 Dynes. Dyne is unit of force in the CGS system.

Under ultra-violet light, three chlorine molecules add to benzene to produce benzene hexachloride. It is also known as gammaxene. Its chemical formula is C₆H₆Cl₆ and undergoes addition reaction.

Aluminum chloride reacts with methyl chloride to form an electrophile. This electrophile attacks the π electron to form carbocation. As a result, alkylbenzene is formed along with HCl as product.

The groups which direct the incoming group to meta position are called meta directing groups. Some examples are -CHO, -COR, -COOH, -CN. The overall electron density on benzene ring decreases. Hence, they are called deactivating groups.

Coelom is the cavity between the body wall and gut wall. It is the fluid filled space other than lymph vessels and blood vessels. Animals are divided into coelomates, acoelomates and pseudocoelomates based on the presence or absence of the coelom or false coelom respectively.

Pseudocoelomates means those organisms with false coelom. Mesoderm in pseudocoelom is scattered into pouches. In pseudocoelomates, coelom is lined partially through mesoderm. Nematodes are examples of pseudocoelomates.

Coelomates is also called as Eucoelomates which means true coelom. Body cavity is lined by mesoderm. Internal organs are suspended in the coelom and are attached through peritoneum. Hemichordates, chordates, annelids and arthropods are the best examples for coelomates.

Body cavity is absent in acoelomates. In this type of animals, mesoderm helps in holding the internal organs in its own place. Coelenterates, platyhelminthes and porifera are the best examples for acoelomates.

Animals classified into coelomates, pseudocoelomates and acoelomates based on the presence or absence of pseudocoelom. Echinoderms, annelids, mollusks and arthropods are examples of coelomates.