Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

 Multiple Choice QuestionsMultiple Choice Questions


Which of the following statements regarding mitochondrial membrane is not correct?

  • The outer membrane is permeable to all kinds of molecules

  • The enzymes of the electron transfer chain are embedded in the outer membrane

  • The inner membrane is highly convoluted forming a series of infoldings

  • The outer membrane resembles a sieve


The enzymes of the electron transfer chain are embedded in the outer membrane

In mitochondria, the enzymes of electron transport chain are found in the inner membrane while outer membrane contains enzymes involved in mitochondrial lipid synthesis and those enzymes that convert lipid substrates into forms that are subsequently metabolised in the matrix.
The outer membrane resembles a sieve that is permeable to all molecule of 10,000 daltons mole. weight or less including small proteins.
The inner membrane is impermeable and highly convoluted, forming a series of infoldings, known as cristate, in the matrix space.



The incomplete breakdown of sugars in anaerobic respiration results in the formation of

  • fructose and water

  • glucose and CO2

  • alcohol and CO2

  • water and CO2


alcohol and CO2

The anaerobic respiration occurs in many bacteria, some fungi, germinating seeds, some fruits and during exergenous exercise. It involves the incomplete breakdown of sugars forming C2H5OH and CO2 as end products and 27 kcal energy is released.


The terminal electron acceptor during electron transport system is

  • oxygen

  • cyto a3

  • cyto c

  • plasto quinone



Oxygen is the terminal acceptor of electron in Electron Transport System(ETS), which in the presence of proton forms a water molecule.


The net gain ATP from complete oxidation of 1 molecule of glucose in eukaryote is

  • 2

  • 4

  • 24

  • 36



There is a total gain of 38 ATP molecules during aerobic respiration. Out of these two molecules of ATP, two are required for transporting the NADH produced in glycolysis (in cytoplasm) into the mitochondria for further oxidation, hence the net gain of ATP is 36 molecules.


Glycolysis occurs in

  • cytosol

  • mitochondria

  • Golgi complex

  • ribosomes



Glycolysis or Embden–Meyerhof–Parnas pathway takes place in cytoplasm. It is a common phase between aerobic and anaerobic respiration. The enzymes occur in cytosol.


Fat, prior to its oxidation associate with

  • cyclic AMP

  • Co- A

  • GMP

  • ATP


Co- A

The respiratory decomposition of fatty acids is known as beta oxidation, which occurs in liver and adipose tissue. Activation of fatty acids takes place, then dehydrogenation of activated fatty acid takes place. It is followed by hydration. The β-hydroxyl acyl derivative is converted to β-keto derivative, which then reacts with Co-A. And it leads to oxidation.


How many ATP molecules could maximally be generated from one molecule of glucose, if the complete oxidation of one mole of glucose to CO2 and H2O yields 686 kcal and the useful chemical energy available in the high energy phosphate bond of one mole of ATP is 12 kcal?

  • Two

  • Thirty

  • Fifty seven

  • One



30 ATP molecules could be generated from 686 Kcal energy.



R.Q. is always less than one in

  • wheat

  • millets

  • bean

  • castor



Respiratory Quotient is the ratio of the volume of carbon- dioxide evolved to that of oxygen consumed by an organism tissue, or cell in a given time. 

In fats, the value of R.Q. is less than one.


How many ATP are formed by oxidation of one glucose molecule in liver cells?

  • 36

  • 38

  • 2

  • 8



In liver cells and prokaryotic cells, 38 ATP are produced by the complete oxidation of one
molecule of glucose.


2 ATP directly = 2 ATP 
2 mol. of NADH = 6 ATP
Pyruvic acid to Acetyl Co-A 2 mol. of NADH Citric acid 6 mol. of NADH cycle
2 mol. of FADH  = 4 ATP
2 mol. of GTP =  2 ATP
Total = 38 ATP


Which one of the following statements is incorrect?

  • The residual air in lungs slightly decreases the efficiency of respiration in mammals

  • The presence of non-respiratory air sacs, increases the efficiency of respiration in birds

  • In insects, circulating body fluids serve to distribute oxygen to tissues

  • The principle of countercurrent flow facilitates efficient respiration in gills of fishes


The residual air in lungs slightly decreases the efficiency of respiration in mammals

Residual air is the air that remains in lungs after the most forceful expiration. It is about 1200 ml. As the residual air remains in the lungs therefore it has no effect on respiration efficiency.