Tag: respiration and associated structures

Questions Related to respiration and associated structures

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 of the following changes occur in diaphragm and intercostal muscles when expiration of air takes place? 

evs respiration in living organisms respiration in human beings respiration and associated structures respiration in humans mechanism of respiration in animals human lungs respiratory organs in humans

  1. Internal intercostal muscles relax and diaphragm contracts

  2. External intercostal muscles and diaphragm relaxes

  3. Internal intercostal muscles contract and diaphragm relax

  4. External intercostal muscles and diaphragm contract

Show answer
Correct Option: C
Explanation:
  • When the internal intercostal muscles contract and diaphragm relax, the ribs move .downward and inward and the diaphragm becomes convex {dome shaped), 
  • thus decreasing the volume of the thoracic cavity and increasing the pressure inside as compared to the atmospheric pressure outside. This will cause the air to move out (expiration).

Read the given statements and select the correct option.


Statement 1 : Mammals can eat while breathing. 

Statement 2 : Mammals have negative-pressure breathing.

evs respiration in living organisms respiration in human beings respiration and associated structures respiration in humans mechanism of respiration in animals human lungs respiratory organs in humans

  1. Both statements 1 and 2 are Correct.

  2. Statement 1 is correct but statement 2 is incorrect.

  3. Statement 1 is incorrect but statement 2 is correct.

  4. Both statements 1 and 2 are incorrect.

Show answer
Correct Option: A
Explanation:
Mammals like humans along with birds and reptiles have negative pressure breathing. They use their mouths for both eating and breathing. Breathing requires pressure gradient. Mammals create pressure gradient using their diaphragm. The high volume and low pressure in the lung cavity results in the air to be sucked in. They cannot swallow and breathe at once. However, it is possible for them to eat while breathing.
Thus, the correct answer is option (A).

Given below is a list of different steps (i-vi) involved in respiration.
(i) Utilisation of $O _2$ by the cells for catabolic reactions
(ii) Transport of gases by the blood
(iii) Pulmonary ventilation by which atmospheric air is drawn in and $CO _2$ is released out
(iv) Release of resultant $CO _2$
(v) Diffusion of $O _2$ and $CO _2$ between blood and tissues
(vi) Diffusion of gases ($O _2$ and $CO _2$) across alveolar tissues.
Select an option which has correct sequence of all the steps.

evs respiration in living organisms respiration in human beings respiration and associated structures respiration in humans mechanism of respiration in animals human lungs respiratory organs in humans

  1. (iii), (vi), (ii), (v), (i), (iv)

  2. (iii), (vi), (i), (v), (ii), (iv)

  3. (iv), (ii), (v), (iii), (i), (vi)

  4. (iv), (vi), (ii), (v), (i), (iii)

Show answer
Correct Option: A
Explanation:

While respiration atmospheric air is drawn in a carbon dioxide is released out, diffusion of gases takes place in the alveolar tissue which is then carried by blood, then diffusion of gases take place between blood and tissues, oxygen is utilized by cells for catabolic reactions, and the resultant carbon dioxide is released from the body.

So, the correct option is '(iii), (vi), (ii), (v), (i), (iv)'.

Consider the following statements each with two blanks. 
(i)    Diaphragm contracts to help in __(1)   while the contraction of abdominal muscles helps in (2). 
(ii). Vital capacity of trained athletes is _(3)__ than that of non-athletes while the vital capacity of non-smokers is (4) than that of smokers. 
(iii) Alveolar P$O {2}$ is  _(5)  than the venous P$O {2}$ while arterial P$O _{2}$ is __(6)_ than the alveolar P$O _{2}$.
Which of the following options gives the correct fill ups for the respective blanks numbers from (1) to (6) in the above statements?

evs respiration in living organisms respiration in human beings respiration and associated structures respiration in humans mechanism of respiration in animals human lungs respiratory organs in humans

  1. (1)-expiration, (2)-inspiration (5)-higher, (6)-lower

  2. (3)-higher, (4)-lower, (5)-lower, (6)-higher

  3. (1)-inspiration, (2)-forced expiration, (3)-higher, (4)-higher

  4. (1)-expiration, (2)-forced expiration, (5)-higher, (6)-lower

Show answer
Correct Option: C
Explanation:

  (i) Diaphragm contracts to help in (1) inspiration while the contraction of abdominal muscles helps in (2) forced expiration.

(ii) Vital capacity of trained athletes is (3) higher than that of non-athletes while the vital capacity of non-smokers is (4) higher than that of smokers.

(iii) Alveolar PO2 is (5) higher than the venous PO2 while arterial PO2 is (6) lower than the alveolar PO2.

So, the correct answer is '(1)-inspiration, (2)-forced expiration, (3)-higher, (4)-higher'.


Complete the following sentence by selecting the correct option.
The breathing rhythm is generated in the (i) and is influenced by variation in levels of (ii)_ in the blood.

evs respiration in living organisms respiration in human beings respiration and associated structures respiration in humans mechanism of respiration in animals human lungs respiratory organs in humans

  1. (i)medulla 

    (ii)$CO _{2}$

  2. (i)medulla 

    (ii)$O _{2}$

  3. (i)frontal lobe 

    (ii)$CO _{2}$ and $O _{2}$

  4. (i)frontal lobe 

    (ii)$CO _{2}$

Show answer
Correct Option: A
Explanation:
The basic rhythm of respiration is generated mainly in the dorsal respiratory group in the medulla. Changes in blood carbon dioxide are believed to stimulate the neurons in the chemosensitive area which affect the rhythm centre. $CO _{2}$ acts by forming carbonic acid which dissociates into H+and $HCO _{3}^{-}$. H+ has a direct effect on this. Oxygen does not have a significant direct effect on rhythm centre.
So the correct answer is 'A'.

The most important muscular structure in respiratory system of rabbit is

evs respiration in living organisms respiration in human beings respiration and associated structures respiration in humans mechanism of respiration in animals human lungs respiratory organs in humans

  1. External intercostal muscles

  2. Internal intercostal muscles

  3. Diaphgram

  4. Vertebral column

Show answer
Correct Option: C
Explanation:

The diaphragm is the dome-shaped sheet of muscle and tendon that serves as the main muscle of respiration and plays a vital role in the breathing process. The diaphragm separates the thoracic cavity containing the heart and lungs, from the abdominal cavity and performs an important function in respiration: as the diaphragm contracts, the volume of the thoracic cavity increases and air is drawn into the lungs.