Question

1. Without or under limited oxygen, respiration switches to fermentation. In humans this process breaks down glucose to yield

A) 2 ethanol, 2 ATP

B) 2 lactate, 2 ATP

C) 2 ethanol, 29 ATP

D) 2 lactate, 29 ATP

2. Rubisco is

A) the enzyme that fixes CO₂ to RuBP

B) a slow enzyme

C) an enzyme that can catalyze two different reactions

D)  All of the above

3. Photosynthesis consists of which two set of reactions that are linked by redox reactions to generate chemical energy

A) light capturing reactions and splitting water  

B) light capturing reactions and chemiosmosis

C) light capturing reactions and Kelvin cycle

D) light capturing reactions and oxidative phosphorylation

4. The M-phase of a somatic cell consists of

A) DNA replications, mitosis

B) meiosis, cytokinesis

C) mitosis, cytokinesis

D) DNA replication, meiosis

Answer 1

Ans) The correct answer is "B" i.e 2 lactate ,2 ATP.

(It is mentioned "In humans" in the question and thus the end result of anaerobic respiration will be lactate or lactic acid wheras in yeast, anaerobic fermentation will give ethanol as the end product. In anaerobic fermentation, 2ATP are produced and not 29ATP).

Ans 2) The correct answer is "C" i.e an enzyme that can catalyze two different reactions (Rubisco is a bifynctional enzyne which can perform oxygenation and carboxylation.When the carbon dioxide is sufficient, it will catalyze carboxylation and if the level of carbon dioxide is not sufficient, then the oxygen will bind to Rubisco and catalyze oxygenation or Photorespiration. Rubisco is involved in the fixation of carbon dioxide to carbohydrates).

Ans 3) The correct answer is "C" i.e light capturing reactions and Calvin cycle

(The light dependent reactions are useful to produce ATP and NADH2 which are used in the dark reactions or calvin cycle to reduce carbon dioxide into carbohydrate.NADH2 act as a hydrogen donor wheras ATP acts as an energy donor.This is also known as interdependence of light and dark reaction)

Ans 4) The correct answer is "C" i.e mitosis,cytokinesis

(As it is already mentioned in the question that it is somatic cell, thus mitosis will occur because meiosis is involved in the formation of gametes and thus it does not occur in somatic cells. DNA replication occurs in the S phase and then there is G2 checkpoint in cell cycle which will check whether there is DNA damage and if the DNA replication has been completed.So,the DNA replication will not occur in the M-Phase.Thus,options A and D can be eliminated).