The major greenhouse gas emitted from agricultural rice paddies is: MCQ with Answer and Explanation

Explanation:
The mitochondrial matrix contains all Krebs cycle enzymes (except succinate dehydrogenase). Thus, the location is due to enzyme presence. R correctly explains A.

Explanation:
The aorta receives blood directly from the left ventricle under high pressure (systolic ~120 mmHg). Pressure decreases as blood moves through arteries, capillaries, and veins. Vena cava pressure is near zero.

Explanation:
Bt cotton is transgenic, containing genes from Bacillus thuringiensis that produce proteins toxic to specific insect pests like the bollworm. Golden rice is genetically modified to produce beta-carotene, a precursor of Vitamin A, to combat deficiency. Cloning involves creating an exact genetic copy of an organism, resulting in genetically identical offspring, not diverse ones. Thus, statements 1 and 2 are correct.