The scientist who developed the first successful heart-lung machine was: MCQ with Answer and Explanation

Explanation:
Green plants (producers) always occupy the first trophic level in a food chain. Energy flow is unidirectional, moving from the sun to producers and then to consumers, never returning to the sun. Due to the 10% law of energy transfer, the pyramid of energy is always upright and can never be inverted. Thus, statements 1 and 2 are correct.

Explanation:
Amphibians have two atria and one ventricle; mixing of blood occurs because of the single ventricle. Complete separation is achieved only in four-chambered hearts. So A true, R false.

Explanation:
RuBisCO (Ribulose-1,5-bisphosphate carboxylase/oxygenase) is the most abundant protein on Earth and the key enzyme in the Calvin cycle (C3 pathway). It catalyzes the fixation of CO2 by attaching it to Ribulose-1,5-bisphosphate (RuBP) to form a 6-carbon intermediate that immediately splits into two molecules of 3-PGA.