Daily NEET MCQ- April 2, 2022 - NEET MCQ

When a force is applied on a solid body, internal forces develop inside it. Pressure is the external force per unit area while stress is the internal force per unit area. Note that pressure and stress aren’t the same.

The initial length of wire is Vol / πr² = 7.85*10^-5/ π*0.005² = 1m.
Stress = Y*strain. F/A = Y*Δl / l.
Δl = F/A * l/Y = (5/πr²)*(1/10¹¹)
= 6.37*10^-7m.

The molecular formula is the exact number of different types of atoms present in the molecule of a compound. An empirical formula is the simplest whole number ratio of various atoms present in a compound. Therefore we can calculate the molecular formula if the molar mass is known.

An empirical formula is the simplest whole number ratio of various atoms present in a compound. Only CH₄ has satisfied the conditions of an empirical formula as it is the simplified whole number ratio compound.

In the molecular formula of glucose that is C₆H₁₂O₆, the carbon, hydrogen, and oxygen are in the ratio of 6:12:6 respectively. So by simplifying them into simpler whole numbers, we obtain 1:2:1. Therefore the empirical formula is CH₂O.

The female sex organs in bryophytes are called archegonium and they produce female gamete called egg. The male sex organ is called antheridium and produce male gametes called antherozoids.

Mosses grow into an intermediary stage from spores called protonema after which they grow into leafy like thallus. Whereas, in liverworts this intermediary stage is absent i.e. the spores develop into thallus without protonema.

In fragmentation, leaves/ stems fall off accidently and grow to form new individuals. Budding is a process in which an outgrowth develops and splits from the parent thallus to produce new individual. Thallus has structures called gemmae cups that contain gemmae which in turn reproduce to form new individual. Sporophyte develops from a developed embryo and results in the formation of spores. Therefore, sporophyte formation is a sexual process that involves two gametes.

Most of the leafy liverworts resemble mosses in their structure. Leafy liverworts contain oil bodies that are absent in mosses. Leafy liverworts contain lobes in their leaves whereas don’t mosses. In mosses, leaves are spirally arranged but in leafy liverworts leaves grow in two or three rows.

Sphagnum belongs to bryophytes and to the sub-classification of mosses. Sphagnum has a very good commercial importance and is used in the packing of cookery and glass materials.