461: Assertion (A) :
To dilute sulphuric acid, acid is added to water and not water to acid.
Reason (R) :
Specific heat of water is quite large.
(a) Both A and R are true, and R is the correct explanation of A
(b) Both A and R are true, but R is not a correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true
Explanation:
Acid is added to water to acid while diluting suplhuric acid because water is having high specific heat thereby it will absorb the large amount of heat released by the acid during dilution.
462: In India, the use of carbofuran, methyl parathion, phorate and triazophos is viewed with apprehension. These chemicals are used as
(a) pesticides in agriculture
(b) preservatives in processed foods
(c) fruit-ripening agents
(d) moisturising agents in cosmetics
Explanation:
Carbofuran, Phorate and Triazophos are pesticides used in agriculture.
To promote organic farming in Kerala, the state agriculture department had ordered a ban on the use of pesticides on May 7. Kerala Agriculture University was asked to provide alternatives to the banned pesticides, which include carbofuran, phorate, methyl parathion, monocrotophos, methyl demethon, prophenophos and triazophos. The university suggested less hazardous pesticides, like acephate, carbaryl, dimethoate and flubendiamide. Hence option A is correct.
Source: https://www.downtoearth.org.in/news/pesticide-ban-lands-kerala-in-court-33657
463: The saliva helps in the digestion of:
(a) Starch
(b) Proteins
(c) Fibres
(d) Fats
464: Consider the following statements :
1. FLISA test is employed as the first and most basic test for an individual to detect cancer.
2. Almost 50% of human beings have Rh+ blood while the remaining have Rh- blood.
Which of the statements given above is/are correct ?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Explanation:
ELISA (Enzyme Linked Immunosorbent Assay) is an important test for diagnosing viral diseases like AIDS (caused by HIV). Majority of the human beings are Rh+ while very few are Rh-.
Erythroblastosis Foetalis : The haemolytic anaemia of newborn infants; when mother is Rh- and father is Rh+, Rh+ infants may develop this condition.
465: Assertion (A) :
Insect resistant transgenic cotton has been produced by inserting Bt gene.
Reason (R) :
The Bt gene is derived from a bacterium.
(a) Both A and R are true, and R is the correct explanation of A
(b) Both A and R are true, but R is not a correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true
Explanation:
Insect resistant transgenic cotton has been produced by inserting Bt gene (Cry 1 AC) taken from a bacterium (Bacillus thuringiensis)