Daily NEET MCQ- September 2, 2022 - NEET MCQ

Prior to World War II, many naturally occurring chemicals such as nicotine were used as pest controlling substances for major crops in agricultural practices. This was achieved by planting tobacco plants in the crop fields.

Hydrogen sulphide is not an organic toxin. It is an inorganic toxin. It exists in the gas phase at ambient temperatures, if finely divided or has a high vapor pressure. But, hydrogen sulphide, becomes far less toxic, when oxidized. Aldrin, Dieldrin, and Toxaphene are organic toxins.

These days, the pesticide industry has shifted its attention to herbicides. During the first half of the last century, this shift from mechanical to chemical weed control had provided the industry with flourishing economic market.

Heat lost by steam = Heat gained by water. Let ‘m’ be the mass of steam required.
∴ mS_steam (120-100) + mL_vap + mS_w (100-85) = 50S_w (85-15) The only variable is ‘m’.
On calculating it from the above equation, we get:
m = 6.19g.

30*1*(T-30) = 1*540 + 1*1*(100-T)
∴ 30T – 900 = 540 + 100 – T
⇒ 31T = 1540
⇒ T = 49.67°C

Let the initial temperature of ice be T°C.
Heat lost by ice will be the same as the heat lost by water.
∴ 1*0.5*(0-T) + 1*80 = 9*1*10
⇒ T = -20°C.

Anthocyanin does not play an important role in photosynthesis whereas the others have an important role. Anthocyanin main role is to provide blue, red and purple color to the plants. It also protects the plants from high temperatures and abiotic stresses.

Green sulfur bacterium does photosynthesis but does not release oxygen. They are anoxygenic. They use H₂S as a substitute for water and utilize sulfide ions to form sulfur and water. No oxygen is formed.

R. Hill found out that oxygen evolved from water in photosynthesis. It was believed that oxygen came from carbon dioxide. Later, Hill’s reaction showed that oxygen was produced from water.

Greenlight is the least effective among the following. Greenlight is reflected by green leaves, so cannot be absorbed. But blue light gives maximum absorption peak of chlorophyll and is most effective.