Tag: biology

Questions Related to biology

Megakaryocytes, special cells in the bone marrow that produce cell fragments are called :

biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

  1. Leucocytes

  2. Erythrocytes

  3. Thrombocytes

  4. Fibrinogen

Show answer
Correct Option: C
Explanation:

Megakaryocyte is a large bone marrow cell which are responsible for the production of thrombocytes. Thrombocytes help in normal blood clotting.

Hence, he correct option is C.

Select the incorrectly matched pair.

biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

  1. Leukopenia - Fall in WBCs count

  2. Polycythemia - Abnormal rise in RBCs count

  3. Thrombocytosis - Decrease in number of platelets

  4. Erythrocytopenia - Decrease in number of RBCs

Show answer
Correct Option: C
Explanation:

(a) Leukopenia is the decrease in the white blood cell count in the cells. 

(b) Polycythemia is a state in which the percentage of red blood cells in our body is elevated. 
(c) Thrombocytosis is the condition in which there is an excessive number of platelets in the blood cell.
(d) Erythrocytopenia-  It is a state in which there is a deficiency of Red blood cells in our body.
So, the correct option is 'Thrombocytosis- Decrease in a number of platelets'.

Tooth extraction in a person causes death due to excessive bleeding. This is because of

biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

  1. Absence of prothrombin

  2. Presence of plasma factor that causes haemorrhage

  3. Presence of plasma factor that prevents blood clotting

  4. Absence of plasma factor required for haemorrhage

Show answer
Correct Option: A
Explanation:

Prothrombin is a glycoprotein occurring in blood plasma and is an essential component of the blood-clotting mechanism. Prothrombin is transformed into thrombin by a clotting factor known as factor X or prothrombinase; thrombin then acts to transform fibrinogen, also present in plasma, into fibrin, which, in combination with platelets from the blood, forms a clot (coagulation). Under normal circumstances, prothrombin is changed into thrombin only when an injury occurs to the tissues or circulatory system or both; therefore, fibrin and blood clots are not formed except in response to bleeding. Hypoprothrombinemia, a deficiency in prothrombin, is characterized by a tendency to prolonged bleeding. It is usually associated with a lack of vitamin K, which is necessary for the synthesis of prothrombin in the liver cells. 

Anaerobic process that takes place after glycolysis is called as

parts of respiration cellular respiration the respiratory system breathing for energy biology types of respiration

  1. TCA

  2. Calvin cycle

  3. Krebs cycle

  4. Fermentation

Show answer
Correct Option: D
Explanation:

Anaerobic process after glycolysis is called as fermentation. Fermentation could be defined as a metabolic process, that converts sugar into acids, gases and alcohol. It occurs in yeast and bacteria, but also in oxygen-starved muscle cells, as in the case of lactic acid fermentation.

What is common in common pathway of aerobic respiration

parts of respiration cellular respiration the respiratory system breathing for energy biology types of respiration

  1. Glycolysis in both aerobic and anaerobic respiration

  2. Krebs cycle common with HMP

  3. Terminal oxidation in both aerobic and anaerobic respiration

  4. Krebs cycle in both aerobic and anaerobic respiration

Show answer
Correct Option: A
Explanation:

Aerobic respiration is the oxidative breakdown of respiratory substrates with the help of atmospheric oxygen. It takes place in three steps: Glycolysis, Kreb's cycle and electron transport chain. Anaerobic respiration is the breakdown of respiratory substrates in the absence of atmospheric oxygen. The first step of aerobic respiration as well as anaerobic respiration is same and takes place in the cytoplasm of cells. Glycolysis is the common pathway of both the processes in which glucose is broken down anaerobically into two molecules of pyruvic acid. 

Thus, the correct answer is option A. 

Read the following four statements (A-D)
A) In fermentation, less than seven percent of the energy in glucose is released
B) Glycolysis occurs in the cytoplasm of the cell and is present only in anaerobic organisms
C) The number of ATP molecules synthesized in ETS depends on the nature of the electron donor
D) In glycolysis, glucose undergoes coin, complete oxidation to form two molecules pyruvic acid
How Many of the above statements are correct?

parts of respiration cellular respiration the respiratory system breathing for energy biology types of respiration

  1. 1

  2. 2

  3. 3

  4. 4

Show answer
Correct Option: B
Explanation:

A) In fermentation, less than seven percent of the energy in glucose is released because only two ATPs are produced at this stage compared to the total number of 32 ATPs in aerobic respiration. The percentage of energy produced is thus (2/32)*100=6.25%.


C) When electrons are transferred from one carrier to next carrier via complexes I to IV in ETS, they are coupled to the production of proton motive force by transport of protons from the lumen to the inner mitochondrial membrane. The number of protons displaced will ultimately determine the number of ATP molecules that will be produced, i.e. for NADH it will be 2.5 and for FADH2 it will be 1.5.


So, the correct option is '2'.

If one triose phosphate completely oxidized inside the prokaryotic cell, then the net gain of ATP of energy is equal to

parts of respiration cellular respiration the respiratory system breathing for energy biology types of respiration

  1. $5$ ATP

  2. $4$ ATP

  3. $20$ ATP

  4. $19$ ATP

Show answer
Correct Option: C
Explanation:

If one triose phosphate completely oxidized inside the prokaryotic cell, then the net gain of ATP of energy is equal to the summation of the ATPs produced at different steps. In the glycolysis step 2 ATP and 1 NADH will be produced followed by 1 NADH in the gateway reaction and 1 GTP, 3 NADH and 1 FADH2 in the TCA cycle. This will add up to 20 ATPs.


So, the correct option is '20 ATP'.

The total number of ATP's formed when one molecule of glucose is oxidized to $CO _2$ to $H _2 O $ is

parts of respiration cellular respiration the respiratory system breathing for energy biology types of respiration

  1. 32

  2. 38

  3. 42

  4. 40

Show answer
Correct Option: B
Explanation:
One molecule of the glucose that enters in the glycolysis produces 2 molecules pyruvate and 2 molecules of NADH$ _{2}$ and 2 ATP.  2 molecules of pyruvate will form 2 molecules of Acetyl Co-A and this will release 2 NADH$ _{2}$. These 2 Acetyl Co-A will enter into Kreb's cycle and will release 6NADH$ _{2}$, 2FADH$ _{2}$ and 2ATP.
so, the total gain before the ETC (electron transport chain) comes out to be  10NADH$ _{2}$, 2FADH$ _{2}$ and 4ATP.
Now, during the electron transport chain, 
10NADH$ _{2}$ will give 10 X 3=30 ATP
2FADH$ _{2}$ will give 2 X 2= 4 ATP
So, 34 ATP from ETC and 4 ATP from Kreb's cycle will be 38 ATP.
Hence, the correct answer is '38'

Total $ATP$ through aerobic EMP pathway can be

parts of respiration cellular respiration the respiratory system breathing for energy biology types of respiration

  1. $6$

  2. $10$

  3. $2$

  4. $8$

Show answer
Correct Option: D
Explanation:

Glycolysis is also known as 'EMP pathway'. It was discovered by three scientist Gustav Embden, Otto Meyerhof, and Jakub Karol Parnas. That's why glycolysis is also known as the EMP pathway. In the EMP pathway, total 8 ATP are produced.

So, the correct answer is '8 ATP'.

Hydrogen acceptor in cellular respiration is 

parts of respiration cellular respiration the respiratory system breathing for energy biology types of respiration

  1. NAD

  2. FAD

  3. NADP

  4. Both A and B

Show answer
Correct Option: D
Explanation:

NAD (Nicotinamide adenine nucleotide) is an electron carrier. It is reduced by accepting a single hydrogen atom and an electron pair from H$ _2$ atom and other electron freed into the medium. NAD is reduced to NADH in citric acid cycle and glycolysis.
FAD (Flavin adenine dinucleotide) is an electron carrier. It is reduced by accepting a full hydrogen H$ _2$ atom. The FAD is reduced to  FADH$ _2$ in the citric acid cycle.
NADP is also an electron carrier. NADP is reduced into NADPH in the photosynthesis.
So, the correct answer is ' NAD & FAD '.