Tag: respiration in organisms

Questions Related to respiration in organisms

Rate of respiration is directly affected by the

zoology respiration in organisms respiration in human beings respiration and associated structures respiration in humans

  1. Concentration of $CO _2$.

  2. Oxygen in trachea.

  3. Concentration of $O _2$.

  4. Diaphragm expansion.

Show answer
Correct Option: A
Explanation:

The rate of respiration is highly dependent on concentration of carbon dioxide. The higher the concentration of carbon dioxide, less is the rate of respiration. Less the concentration of oxygen and more is the concentration of carbon dioxide, respiration rate increases.

So, option A "Concentration of Carbon dioxide"is the correct option.

Which of the following gases makes the most stable combination with the haemoglobin of red blood cells? 

zoology respiration in organisms respiration in human beings respiration and associated structures respiration in humans

  1. ${ CO } _{ 2 }$

  2. $CO$

  3. ${ O } _{ 2 }$

  4. ${ N } _{ 2 }$

Show answer
Correct Option: B
Explanation:
  • The combination of oxygen with haemoglobin is called oxyhaemoglobin and this oxygenated blood is carried away from the lungs through the bloodstream to all the tissues of the body. 
  • Carbon monoxide can also bind to haemoglobin but does so about 240 times more tightly than oxygen, forming a compound called carboxyhaemoglobin. 
  • This means that if both carbon monoxide and oxygen are inhaled, carbon monoxide will preferentially bind to haemoglobin. 
  • This reduces the amount of haemoglobin available to bind to oxygen, so the body and tissues become starved of oxygen.

Which of the following is not a characteristic of good respiratory surface?

zoology respiration in organisms respiration in human beings respiration and associated structures respiration in humans

  1. Thin and moist

  2. Large surface area

  3. Close to oxygen and gas transport.

  4. Thick and dry surface

Show answer
Correct Option: D
Explanation:

The characteristics of a respiratory surface are thin walls, a moist inner surface, a huge combined surface area, a rich blood supply each alveolus is sounded by capillaries. Surfaces which dries out easily, thick and easily damaged are not a characteristic of good respiratory surface. 

Therefore, the correct answer is option D.

The rate of breathing is lowest when we are

zoology respiration in organisms respiration in human beings respiration and associated structures respiration in humans

  1. Eating.

  2. Sleeping.

  3. Playing.

  4. Running.

Show answer
Correct Option: B
Explanation:

The respiratory rate or breathing frequency is the rate at which the number of inhalation and exhalation cycles are  taken within a set time.  The typical respiratory rate for a healthy adult at rest is 12–20 breaths per minute. However, the average resting respiratory rates differ with age. Food stimulates the nervous system which further tends to increase respiration rate.

Therefore, the correct answer is option B.

Lack of oxygen in body fluids is known as

zoology respiration in organisms respiration in human beings respiration and associated structures respiration in humans

  1. Hyperpnoea.

  2. Anoxemia.

  3. Anoxia.

  4. Hypoxia.

Show answer
Correct Option: B
Explanation:

The lack of oxygen or a lowering of the normal level of oxygen in the blood and body fluids is known as anoxemia and is generally experienced when in high altitudes.  

Therefore, the correct answer is option B.

Most of the carbon dioxide in the blood is carried in the form of 

zoology respiration in organisms respiration in human beings respiration and associated structures respiration in humans

  1. Carbonic acid.

  2. Bicarbonates.

  3. Carbaminohaemoglobin.

  4. Dissolved CO$ _2$.

Show answer
Correct Option: B
Explanation:

The majority of carbon dioxide molecules (85 percent) are carried as part of the bicarbonate buffer system. In this system, carbon dioxide diffuses into the red blood cells. Carbonic anhydrase (CA) within the red blood cells quickly converts the carbon dioxide into carbonic acid (H$ _2$CO$ _3$). Carbonic acid is an unstable, intermediate molecule that immediately dissociates into bicarbonate ions (HCO$ _3$−) and hydrogen (H+) ions. Since carbon dioxide is quickly converted into bicarbonate ions, this reaction allows for the continued uptake of carbon dioxide into the blood, down its concentration gradient. It also results in the production of H+ ions. If too much H+ is produced, it can alter blood pH. However, hemoglobin binds to the free H+ ions, limiting shifts in pH. The newly-synthesized bicarbonate ion is transported out of the red blood cell into the liquid component of the blood in exchange for a chloride ion (Cl-). This is called the chloride shift. When the blood reaches the lungs, the bicarbonate ion is transported back into the red blood cell in exchange for the chloride ion. The H+ ion dissociates from the hemoglobin and binds to the bicarbonate ion. This produces the carbonic acid intermediate, which is converted back into carbon dioxide through the enzymatic action of CA. The carbon dioxide produced is expelled through the lungs during exhalation. 

Therefore, the correct answer is option B.

Select the wrong statement(s) about respiration.
a) It consists of breathing, oxidation of food and energy storage in the form of ATP.
b) Cytoplasm and mitochondria are necessary for the completion of aerobic respiration.
c) Complete oxidation of food into ethanol or lactic acids, $CO _2$ and few molecules of ATP are seen in anaerobic respiration.
d) In the older portions of woody plants, the gaseous exchange takes place through stomatal apertures.
Statements that are entirely wrong are

zoology respiration in organisms respiration in human beings respiration and associated structures respiration in humans

  1. a) and b)

  2. b) and c)

  3. a) and d)

  4. c) and d)

Show answer
Correct Option: D
Explanation:

Anaerobic respiration takes place in the absence of oxygen. So, oxidation of food does not take place. So, statement c is wrong. Gaseous exchange occurs through leaves that have minute tiny apertures over them called stomata. 

Statement a and b are true. We know that respiration consists of breathing, which includes inhalation and exhalation, oxidation of food and also it stores energy the form of ATP. The cytoplasm is the jelly-like fluid matrix that contains different cell organelles like mitochondria. All the steps of cellular respiration occur inside mitochondria.
So, statement (c) and (d) are wrong statements and option D is the correct answer.

Which is true about the end products of glycolysis?
bio-chemistry respiration in organisms glucose metabolism the need for energy in living organism respiratory function

  1. $2\,pyruvic \,acid+2ATP+{2NADH} _{2}$

  2. $2\,pyruvic \,acid+{2NADH} _{2}$

  3. $1\,pyruvic \,acid+2ATP+{2NADH} _{2}$

  4. $2\,pyruvic \,acid+1ATP+{1NADH} _{2}$

Show answer
Correct Option: A
Explanation:
In glycolysis, two molecules of ATP are consumed during two phosphorylation reactions to form fructose 1, 6-biphosphate. In return, four molecules of ATP are produced by substrate-level phosphorylation (conversion of 1, 3-biphosphoglycerate to 3-phosphoglycerate and phosphoenolpyruvate to pyruvate). Two molecules of ${NADH} _{2}$ are formed at the time of oxidation of glyceraldehyde 3-phosphate to 1, 3-biphosphoglycerate. The net reaction of glycolysis is as follows:

$Glucose+{2NAD}^{+}+2ADP+{2H} _{3}{PO} _{4}\rightarrow2Pyruvate+2NADH+{2H}^{+}+2ATP$

Each NADH is equivalent to 3 ATP, so the net gain in glycolysis is 8 ATP.

So the correct answer is '$2\,pyruvic \,acid+2ATP+{2NADH} _{2}$'.

In glycolysis, glucose molecule is converted into which substance?

bio-chemistry respiration in organisms glucose metabolism the need for energy in living organism respiratory function

  1. Lactic acid

  2. Ethanol

  3. Pyruvate

  4. Amino acid

Show answer
Correct Option: C
Explanation:

The process by which the glucose (6C compound) is split into two molecules of pyruvic acid (3C compound) is called glycolysis or EMP pathway. It occurs in the cytoplasm. In glycolysis, 4ATP and 2NADH$ _2$ molecules are formed and 2ATP molecules are consumed in hexose phase

So, the correct answer is 'Pyruvate'

For the start of respiration, a living cell requires

bio-chemistry respiration in organisms glucose metabolism the need for energy in living organism respiratory function

  1. Glucose

  2. Glucose + $O _2$

  3. $O _2$

  4. Glucose + ATP

Show answer
Correct Option: D
Explanation:

The mechanism of respiration is initiated by breaking down glucose to pyruvic acid without the help of oxygen. The initial process occurs in the cytosol of cells which requires glucose as well as ATP molecules which provide energy for the process to start. This initial process is known as glycolysis and it takes place in 10 steps in which total 4 ATP molecules are produced and 2 ATP molecules are consumed. Thus, these are the net production of 2 ATP molecules. 

Thus, the correct answer is option D.