Text Book Back Questions and Answers - Chapter 6 Respiration 11th Biology Zoology Guide Samacheer Kalvi Solutions - SaraNextGen [2024-2025]

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On April 24, 2024, 11:35 AM

Respiration
Text Book Back Questions and Answers
I. Multiple Choice Questions
Question 1.
Breathing is controlled by
(a) cerebrum
(b) medulla oblongata
(c) cerebellum
(d) pons
Answer:
(b) medulla oblongata
Question 2.
Intercostal muscles are found between the
(a) vertebral column
(b) sternum
(c) ribs
(d) glottis
Answer:
(c) ribs
Question 3.
The respiratory structures of insects are
(a) tracheal tubes
(b) gills
(c) green glands
(d) lungs
Answer:
(a) tracheal tubes
Question 4.
Asthma is caused due to

(b) inflammation of branchiole
(c) damage of diaphragm
(d) infection of lungs
Answer:
(d) infection of lungs
Question 5.
The Oxygen Dissociation Curve is
(a) sigmoid
(b) straight line
(c) curved
(d) rectangular hyperbola
Answer:
(a) sigmoid
Question 6.
The Tidal Volume of a normal person is
(a) $800 \mathrm{~mL}$
(b) $1200 \mathrm{~mL}$
(c) $500 \mathrm{~mL}$
(d) $1100-1200 \mathrm{~mL}$
Answer:
(c) $500 \mathrm{~mL}$
Question 7.
During inspiration, the diaphragm
(a) expands
(b) unchanged
(c) relaxes to become dome-shaped
(d) contracts and flattens
Answer:
(d) contracts and flattens
Question 8.
$\mathrm{CO}_2$ is transported through blood to lungs as
(a) carbonic acid

(b) oxyhaemoglobin
(c) carbamino haemoglobin
(d) carboxy haemoglobin
Answer:
(c) carbamino haemoglobin
Question 9.
When $1500 \mathrm{~mL}$ air is in the lungs, it is called
(a) vital capacity
(b) tidal volume
(c) residual volume
(d) inspiratory reserve volume
Answer:
(b) tidal volume
Question 10.
Vital capacity is
(a) TV + IRV
(b) TV + ERV
(c) $R V+E R V$
(d) $\mathrm{TV}+\mathrm{TRV}+\mathrm{ERV}$
Answer:
(d) $\mathrm{TV}+\mathrm{TRV}+\mathrm{ERV}$
Question 11.
After a long deep breath, we do not respire for some seconds due to
(a) more $\mathrm{CO}_2$ in the blood
(b) more $\mathrm{O}_2$ in the blood
(c) less $\mathrm{CO}_2$ in the blood
(d) less $\mathrm{CL}$ in the blood
Answer:
(b) more $\mathrm{O}_2$ in the blood
Question 12.
Which of the following substances in tobacco smoke damage the gas exchange system?

(a) carbon monoxide and carcinogens
(b) carbon monoxide and nicotine
(c) carcinogens and tar
(d) nicotine and tar
Answer:
(d) nicotine and tar
Question 13.
Column I represents diseases and column II represents their symptoms. Choose the correctly paired option

(a) $P=$ iii, $Q=$ ii, $R=$ i
(b) $P=$ iii, $Q=i, R=$ ii
(c) $P=$ ii, $Q=$ iii, $R=$ i
(d) $P=$ ii, $Q=$ i, $R=$ iii
Answer:
(a) $P=$ iii, $Q=$ ii, $R=$ i
Question 14.
Which of the following best describes the process of gas exchange in the lungs?
(a) Air moves in and out of the alveoli during breathing.
(b) Carbon dioxide diffuses from deoxygenated blood in capillaries into the alveolar air.
(c) Oxygen and carbon dioxide diffuse down their concentration gradients between blood and alveolar air.
(d) Oxygen diffuses from alveolar air into deoxygenated blood.
Answer:
(c) Oxygen and carbon dioxide diffuse down their concentration gradients between blood and alveolar air.
Question 15.
Make the correct pairs.

(a) P - i, Q - ii, R - iii, S - iv
(b) $P-i i, Q-i i i, R-i v, S-i$
(c) $P-i i, Q-i i i, R-i, S-i v$
(d) $P-i i i, Q-i v, R-i, S-i i$
Answer:
(d) P - iii, Q - iv , R - i, S-ii

Question 16.
Make the correct pairs.

(a) $P-$ ii, $Q-i v, R-i, S-i i i$
(b) $P-$ iii. $Q-i i, R-$ iv , $S-$ i
(c) $P-i i, Q-i v, R-i i i, S-i$
(d) $P-$ iii , $Q-i v, R-i, S-i i$
Answer:
(a) $P-i i, Q-i v, R-i, S-i i i$
II. Very Short Answer Questions
Question 17.
Name the respiratory organs of flatworm, earthworm, fish, prawn, cockroach and cat.
Answer:
Flatworm - Body surface Earthworm - Moist skin Fish - Gills Prawn - Gills Cockroach - Trachea Cat - Lungs
Question 18.
Name the enzyme that catalyses the bicarbonate formation in RBCs.
Answer:
Carbonic anhydrase.
Question 19.
Air moving from the nose to the trachea passes through a number of structures. List in order of the structures.
Answer:

Question 20.
Which structure seals the larynx when we swallow?
Answer:
Epiglottis.
III. Short Answer Questions
Question 21.
Resistance in the airways is typically low. Why? Give two reasons.
Answer:
The airway resistance is low because:
- The diameter of most airways is relatively large.
- For smaller airways there are many in parallel, making their combined diameter large.
- Air has a low viscosity.
Question 22.
How the body makes long-term adjustments when living in high altitude?
Answer:
When a person lives in higher altitude, the body makes respiratory and hematopoietic . adjustment. Kidneys accelerate the production of the hormone erythropoietin which stimulate the bone marrow to produce more RBCs. This improves the binding of 02 with haemoglobin.
Question 23.
Why is pneumonia considered a dangerous disease?
Answer:

Inflammation of the lungs due to infection caused by bacteria or virus is called pneumonia. The symptoms are sputum production, nasal congestion, shortness of breath, sore throat etc. The alveoli get filled with fluid or pus, making is difficult to breathe (lung abscesses).
Question 24.
Diffusion of gases occurs in the alveolar region only and not in any other part of the respiratory system. Discuss.
Answer:
The alveolar region is highly vascular. Each alveolus is made up of highly permeable and thin layers of squamous epithelial cells. The barrier between the alveoli and the capillaries is thin and diffusion of gases takes place from higher partial pressure to low er partial pressure. Hence, gaseous exchange takes place in the aboral region only but not in any other part of the respiratory system.
Question 25.
Sketch a flow chart to show the path way of air flow during respiration.
Answer:

Question 26.
Explain the conditions which creates problems in oxygen transport.
Answer:
When a person travels quickly from sea level to elevations above $8000 \mathrm{ft}$, where the atmospheric pressure and partial pressure of oxygen are lowered, the individual responds with symptoms of acute mountain sickness (AMS)headache, shortness of breath, nausea and dizziness due to poor binding of $\mathrm{O}_2$ with haemoglobin. When the person moves on a long-term basis to mountains from sea level his body begins to make respiratory and haematopoietic adjustments.
To overcome this situation kidneys accelerate production of the hormone erythropoietin, which stimulates the bone marrow to produce more RBCs. When a person descends deep into the sea, the pressure in the surrounding water increases which causes the lungs to decrease in volume.

This decrease in volume increases the partial pressure of the gases within the lungs. This effect can be beneficial, because it tends to drive additional oxygen into the circulation, but this benefit also has a risk, the increased pressure can also drive nitrogen gas into the circulation.

This increase in blood nitrogen content can lead to a condition called nitrogen narcosis. When the diver ascends to the surface too quickly a condition called 'bends' or decompression sickness occurs and nitrogen comes out of solution while still in the blood forming bubbles. Small bubbles in the blood are not harmful, but large bubbles can lodge in small capillaries, blocking blood flow or can press on nerve endings.

Decompression sickness is associated with pain in joints and muscles and neurological problems including stroke. The risk of nitrogen narcosis and bends is common in scuba divers. During carbon-dioxide poisoning, the demand for oxygen increases. As the 02 level in the blood decreases it leads to suffocation and the skin turns bluish black.
Entrance Examination Questions Solved
Choose the correct answer
Question 1.
The length of human trachea is about
(a) 6 inches
(b) $12 \mathrm{~cm}$
(c) 12 inches
(d) $18 \mathrm{~cm}$
Answer:
(b) $12 \mathrm{~cm}$
Question 2.
Hamburger's phenomenon is also known as
(a) $\mathrm{HCO}_3$ shift
(b) $\mathrm{Na}+$ shift
(c) $\mathrm{H}+$ shift
(d) Chloride shift
Answer:
(d) Chloride shift

Question 3.
Oxygen carrying capacity of blood is
(a) $20 \%$
(b) $30 \%$
(c) $40 \%$
(d) $50 \%$
Answer:
(a) $20 \%$
Question 4.
Respiratory movements are controlled by
(a) Cerebellum
(b) Cerebrum
(c) Medulla oblongata
(d) Crura cerebri
Answer:
(c) Medulla oblongata
Question 5.
At higher $\mathrm{CO}_2$ concentration, oxygen dissociation curve of haemoglobin will
(a) Move to left
(b) Move to right
(c) Become irregular
(d) Move upwardly
Answer:
(b) Move to right
Question 6.
Chloride shift is required for transport of
(a) Nitrogen
(b) Oxygen
(c) Carbon dioxide

(d) Carbon dioxide and oxygen
Answer:
(c) Carbon dioxide
Question 7.
Volume of air inspired or expired with each normal breath is known
(a) Inspiratory capacity
(b) Total Lung capacity
(c) Tidal volume
(d) Residual volume
Answer:
(c) Tidal volume
Question 8.
Oxygen haemoglobin dissociation curve will shift to right on decrease of
(a) Acidity .
(b) Carbon dioxide concentration
(c) Temperature
(d) $\mathrm{pH}$
Answer:
(d) $\mathrm{pH}$
Question 9.
Double membrane pleural sac
(a) Envelops the kidneys
(b) Envelops the brain
(c) Envelops the lungs
(d) Lines the nasal passage
Answer:
(c) Envelops the lungs
Question 10.
Volume of air remaining in lungs after maximum respiratory' effort is

(a) Vital capacity
(b) Residual volume
(c) Total lung capacity
(d) Tidal volume
Answer:
(b) Residual volume
Question 11.
In expiration, diaphragm becomes
(a) Flattened
(b) Relaxed
(c) Straightened
(d) Arched
Answer:
(b) Relaxed
Question 12.
Carbon dioxide is transported from tissues to respiratory surface by only
(a) Plasma and erythrocytes
(b) Plasma
(c) Erythrocytes
(d) Erythrocytes and leucocytes
Answer:
(a) Plasma and erythrocytes
Question 13.
Respiratory centre is situated in 
(a) Cerebellum
(b) Medulla oblongata
(c) Hypothalamus
(d) Cerebrum
Answer:
(b) Medulla oblongata

Question 14.
Air is breathed through
(a) Trachea $\rightarrow$ lung $\rightarrow$ laiyn $x \rightarrow$ phaiyn $x \rightarrow$ alveoli
(b) Nose $\rightarrow$ laryn $x \rightarrow$ pharyn $x \rightarrow$ alveoli $\rightarrow$ bronchioles
(c) Nostrils $\rightarrow$ pharynx $\rightarrow$ laryn $\rightarrow$ trachea bronchi $\rightarrow$ bronchioles $\rightarrow$ alveoli
(d) Nose $\rightarrow$ mouth $\rightarrow$ lungs.
Answer:
(c) Nostrils $\rightarrow$ pharynx $\rightarrow$ laryn $x \rightarrow$ trachea bronchi $\rightarrow$ bronchioles $\rightarrow$ alveoli
Question 15.
Which is false?
(a) Blood from right side of heart is carried to lungs by pulmonary artery
(b) Pleura is double covering of kidney
(c) Pancreas is both exocrine \& endocrine gland
(d) Scurvy is due to vitamin C deficiency
Answer:
(b) Pleura is double covering of kidney
Question 16.
Volume of air breathed in and out during effortless respiration is
(a) residual volume
(b) vital volume
(c) tidal volume
(d) normal volume
Answer:
(c) Tidal volume
Question 17.
Body tissue obtain oxygen from haemoglobin due to its dissociation in tissues is caused by
(a) Low oxygen concentration and high carbon dioxide concentration
(b) Low oxygen concentration
(c) Low carbon dioxide concentration
(d) High carbon dioxide concentration
Answer:
(b) Low oxygen concentration

Question 18.
Lungs have a number of alveoli for
(a) Having spongy texture and proper shape
(b) More surface area for diffusion of gases
(c) More space for increasing volume of inspired air
(d) More nerve supply
Answer:
(b) More surface area for diffusion of gases
Question 19.
Presence of large number of alveoli around alveolar ducts opening into bronchioles in mammalian lungs is
(a) Inefficient system of ventilation with little of residual air
(b) Inefficient system of ventilation with high percentage of residual air
(c) An efficient system of ventilation with no residual air
(d) An efficient system of ventilation with little residual air
Answer:
(d) An efficient system of ventilation with little residual air
Question 20.
During transport of $\mathrm{CO}_2$ blood does not become acidic due to
(a) Neutralisation of $\mathrm{H}_2 \mathrm{CO}_2$ by $\mathrm{Na}_2 \mathrm{CO}_3$
(b) Absorption by leucocytes
(c) Blood buffers
(d) Non-accumulation
Answer:
(c) Blood buffers
Question 21.
At high altitude, RBCs of human blood will
(a) Increase in number
(b) Decrease in number
(c) Decrease in size
(d) increase in size
Answer:
(a) Increase in number

Question 22.
$\mathrm{CO}_2$ is transported
(a) as dissolved in blood plasma
(b) as carbamino haemoglobin
Answer:
(d) as carbamino haemoglobin and carbonic acid
Question 23.
Maximum amount 70-75\% of carbon dioxide transport occursa.

(a) Dissolved in plasma
(b) Carbaminohaemoglobin complex
(c) Bicarbonate
(d) None of the above
Answer:
(c) Bicarbonate
Question 24.
Trachea is lined with incomplete rings of
(a) Fibrous cartilage
(b) Calcified cartilage
(c) Elastic cartilage
(d) Hyaline cartilage
Answer:
(d) Hyaline cartilage
Question 25.
Oxygen and carbon dioxide are transported in blood through
(a) Platelets and corpuscles
(b) RBCs and WBCs
(c) WBCs and serum
(d) RBCs and plasma
Answer:
(d) RBCs and plasma

Question 26.
About $1500 \mathrm{ml}$ of air left in lungs is called
(a) Tidal volume
(b) Inspiratory reserve volume
(c) Residual volume
(d) Vital capacity
Answer:
(c) Residual volume
Question 27.
Which one protects the lungs?
(a) Ribs
(b) Vertebral column
(c) Sternum
(d) All the above
Answer:
(d) All the above
Question 28.
Which one has the lowest value?
(a) Tidal volume
(b) Vital capacity
(c) Inspiratory reserve volume
(d) Expiratory reserve volume
Answer:
(b) Vital capacity
Question 29.
A child was killed through asphyxiation. Post morturm confirmed it because a piece of lung put in water 
(a) Settled down
(b) Kept floating
(c) Had blood spots
(d) None of the above
Answer:
(b) Kept floating

Question 30.
Amount of oxygen present in one gram of haemoglobin is
(a) $20 \mathrm{ml}$
(b) 1-34 ml
(c) $13-4 \mathrm{ml}$
(d) None of the above
Answer:
(b) 1-34 $\mathrm{ml}$
Question 31.
A molecule of haemoglobin carries how many oxygen molecules 
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(d) 4
Question 32.
In carbon monoxide poisoning there is 
(a) Increase in carbon dioxide concentration
(b) Decrease in oxygen availability
(c) Decrease in free haemoglobin
(d) None of the above
Answer:
(c) Decrease in free haemoglobin
Question 33.
Exchange of gases in lung alveoli occurs through
(a) Active transport
(b) Osmosis
(c) Simple diffusion
(d) Passive transport

Answer:
(c) Simple diffusion
Question 34.
Haemoglobin is
(a) Vitamin
(b) Skin pigment
(c) Blood carrier
(d) Respiratory pigmentc
Answer:
(d) Respiratory pigmentc
Question 35.
Vocal cords occur in
(a) Pharynx
(b) Larynx
(c) Glottis
(d) Bronchial tube
Answer:
(b) larynx
Question 36.
The cells which do not respire
(a) Epidermal cells
(b) Sieve cells
(c) Cortical cells
(d) Erythocytes
Answer:
(d) Erythocytes
Question 37.
Hiccough (hiccup) is due to activity of
(a) Intercostal muscles
(b) Food in air tract
(e) Diaphragm
(d) Inadequate oxygen in environment

Answer:
(c) Diaphragm
Question 38.
Bicarbonate formed inside erythrocytes moves out to plasma while chloride of plasma pass into erythrocytes. The phenomenon is called
(a) Bicarbonate shift
(b) Carbonation
(c) Hamburger phenomenon
(d) None of the above
Answer:
(c) Hamburger phenomenon
Question 39.
Respiratory centre of brain is stimulated by
(a) Carbon dioxide content in venous blood
(b) Carbon dioxide content in arterial blood
(c) Oxygen content in venous blood
(d) Oxygen content in arterial blood
Answer:
(d) Oxygen content in arterial blood
Question 40.
A higher $\mathrm{CO}_2$ concentration of blood causes 
(a) Slow diffusion of $\mathrm{CO}_2$ from blood
(b) Slow transport of $\mathrm{CO}_2$ from blood
(c) Slow diffusion of $\mathrm{O}$, from blood
(d) Both $A$ and $B$
Answer:
(c) Slow diffusion of $\mathrm{O}_2$ from blood
Question 41.
Gases diffuse over the respiratory surface because of
(a) $\mathrm{O}$, is more in alveoli than in blood
(b) 02 is more in blood than in tissues
(c) $\mathrm{CO}_2$ is more in alveoli than in blood

(d) $\mathrm{PCO}_2$ is more in blood than in tissues
Answer:
(a) 02 is more in alveoli than in blood
Question 42.
Dissociation curve of 02 (which is dissociation from $\mathrm{Hb}$ ) shifts to the rights
(a) 02 concentration decrease
(b) $\mathrm{CO}_2$ concentration decreases
(c) $\mathrm{CO}_2$ concentration increase
(d) Chloride concentration increases
Answer:
(c) $\mathrm{CO}_2$ concentration increase
Question 43.
Thoracic cage of man is formed of 
(a) Ribs and sternum
(b) Ribs, sternum and thoracic vertebrae
(c) Ribs,sternum and lumbar vertebrae
(d) Ribs and thoracic vertebrae
Answer:
(b) Ribs, sternum and thoracic vertebrae
Question 44.
Vital capacity of lung is equal to
(a) IRV + ERV + TV
(b) $I R V+E R V+T V-R V$
(c) IRV + ERV + TV + RV
(d) IRV + ERV
Answer:
(a) IRV + ERV + TV
Question 45.
Dead space is
(a) Upper respiratory tract
(b) Nasal chambers

(c) Alveolar space
(d) Lower respiratory tract
Answer:
(a) Upper respiratory tract
Question 46.
Carbon monoxide contained in Tobacco smoke
(a) Is carcinogenic
(b) Causes gastric ulcers
(c) Reduces oxygen carrying capacity of blood
(d) Raises blood pressure
Answer:
(c) Reduces oxygen carrying capacity of blood
Question 47 .
What is correct?
(a) Pulmonary ventilation is equal to alveolar ventilation
(b) Alveolar ventilation is less than pulmonary ventilation
(c) Alveolar ventilation is more than pulmonary ventilation
(d) Both are variable
Answer:
(b) Alveolar ventilation is less than pulmonary ventilation
Question 48.
Increase in $\mathrm{CO}_2$ concentration shall cause
(a) Slower and shallower breathing
(b) Slower and deeper breathing
(e) Faster and deeper breathing
(d) No effect on breathing
Answer:
(c) Faster and deeper breathing
Question 49.
Alveoli become enlarged and damaged with reduced surface area in heavy smokers. the condition is called
(a) Silicosis

(b) Emphysema
(c) Asthma
(d) Bronchitis
Answer:
(b) Emphysema
Question 50.
SARS is caused by a variant of
(a) Pneumococcus pneumonia
(b) Common cold by Corona virus
(c) Asthma
(d) Bronchitis
Answer:
(b) Common cold by Corona virus
Question 51.
During inspiration
(a) Diaphragm and external muscles relax
(b) Diaphragm and internal intercostal muscles relax
(c) Diaphragm and external intercostal muscles contract
(d) Diaphragm and internal intercostal muscles contract Answer:
(c) Diaphragm and external intercostal muscles contract
Question 52.
Mountain sickness at high altitude is due to
(a) Excess $\mathrm{CO}_2$ in blood
(b) Decreased $\mathrm{CO}_2$ in air
(c) Decreased partial pressure of oxygen
(d) Decreased efficiency of haemoglobin
Answer:
(c) Decreased partial pressure of oxygen
Question 53.
Capacity of human lungs for air in a healthy person is
(a) $3000 \mathrm{ml}$

(b) $1500 \mathrm{ml}$
(c) $1000 \mathrm{ml}$
(d) $500 \mathrm{ml}$
Answer:
(a) $3000 \mathrm{ml}$
Question 54.
Rate of breathing is controlled by
(a) Amount of freely available oxygen
(b) Carbon dioxide in blood
(c) Muscular functions of body
(d) All the above
Answer:
(b) Carbon dioxide in blood
Question 55.
During strenuous exercise,glucose is converted into
(a) Glycogen
(b) Pyruvic acid
(c) Starch
(d) Lactic acid
Answer:
(d) Lactic acid
Question 56.
How much pulmonary air is expired normally?
(a) $70^{\circ}$ io
(b) $20 \%$
(c) $25 \%$
(d) $32 \%$
Answer:
(d) $32 \%$
Question 57.
Which is incorrect?
(a) Presence of non-respiratory air sacs increases efficiency of respiration in birds
(b) In insects, circulation body fluids serve to distribute oxygen to tissues
(c) Principle of counter - current flow facilitates efficient respiration in gills of fishes
(d) Residual air in lungs slightly decreases the efficiency of respiration in mammals
Answer:
(b) In insects, circulation body fluids serve to distribute oxygen to tissues
Question 58.
Percentage of oxygen being carried by blood plasma is
(a) 6-9\%
(b) $3-6 \%$
(c) $2-3 \%$
(d) $1-2 \%$
Answer:
(c) $2-3 \%$
Question 59.
Name of the pulmonary disease in which alveolar surface area involved in gas exchange is drastically reduced due to damage in the alveolar walls: 
(a) Asthma
(b) Pleurisy
(c) Emphysema
(d) Pneumonia
Answer:
(c) Emphysema
Question 60.
Asthma may be attributed to
(a) bacterial infection of the lungs
(b) allergic reaction of the mast cells in the lungs
(c) inflammation of the trachea
(d) accumulation of fluid in the lungs

Answer:
(b) allergic reaction of the mast cells in the lungs
Question 61.
Name the chronic respiratory disorder caused mainly by cigarette smoking:
(a) Emphysema
(b) Asthma
(c) Respiratory acidosis
(d) Respiratory alkalosis
Answer:
(a) Emphysema
Question 62.
Lungs are made up of air-filled sacs, the alveoli. They do not collapse even after forceful expiration.
(a) Inspiratory Reserve Volume
(b) Tidal Volume
(c) Expiratory Reserve Volume
(d) Residual Volume
Answer:
(d) Residual Volume