CBSE Class 12 Biology Respiration MCQs

Question. During hibernation frog performs
(a) Pulmonary respiration
(b) Cutaneous respiration
(c) Bucco-pharyngeal respiration
(d) Both cutaneous and pulmonary respiration

Answer : B

Question. Skin is an accesory organ of respiration in
(a) Humans
(b) Frog
(c) Rabbit
(d) Lizard

Answer : B

Question. Diffusion of oxygen in tissues of Cockroach occurs through
(a) Blood
(b) Integument
(c) Tracheae
(d) Tracheoles

Answer : D

Question. Fish brought out of water dies because of
(a) Absence of pressure
(b) Inability to respire
(c) Inability to feed
(d) Rise in temperature

Answer : B

Question. Book lungs are respiratory structures of
(a) Arachnida
(b) Mollusca
(c) Mammals
(d) Earthworm

Answer : A

Question. In crustacea respiration occurs through
(a) Tracheae
(b) Gills
(c) Book lungs
(d) Book gills

Answer : B

Question. Respiratory organ of terrrestrial vertebrates are
(a) Gills
(b) Lungs
(c) Skin
(d) Body surface

Answer : B

Question. Organism show anaerobic respiration-
(a) Earthworm
(b) Tapeworm
(c) Lizard
(d) Bat

Answer : B

Question. Which one of these statements is correct?
(a) all animals require a medium for cellular respiration
(b) in all animals oxygen is transported by blood
(c) all animals take oxygen from water or air through gills of lungs
(d) all animals need oxygen for respiration

Answer : A

Question. In frog, cutaneous respiration takes place:
(a) only on land
(b) only in water with pulmonary respiration
(c) only in water when pulmonary respiration is not occurring
(d) always

Answer : D

Question. Respiratory organs in scorpion are:
(a) Gills
(b) Booklungs
(c) Skin
(d) Bookgills

Answer : B

Question. In mammals the body cavity is partitioned into thoracic and abdominal parts of
(a) Liver
(b) Lungs
(c) Ribs
(d) Diaphragm

Answer : D

Question. Arytenoid cartilage occurs in
(a) Larynx
(b) Nose
(c) Hyoid
(d) Sternum

Answer : A

Question. Lining of trachea is made of
(a) Simple squamous epithelium
(b) Simple cuboidal epithelium
(c) Pseudostratified epithelium
(d) Stratified cuboidal epithelium

Answer : C

Question. Epithelium lining bronchioles is
(a) Pseudostratified columnar
(b) Pseudostratified sensory
(c) Squamous scnsory
(d) Cuboidal and columnar

Answer : D

Question. Numbers of lobes in right and left lungs of human are :
(a) 2, 4
(b) 3, 2
(c) 4, 2
(d) 6, 3

Answer : B

Question. Covering of the lungs is called :
(a) Perichondrium
(b) Pleural membrane
(c) Pericardium
(d) Peritoneum

Answer : B

Question. Thyroid cartilage is found in :
(a) Nose
(b) Pharynx
(c) Larynx
(d) Ear pinna

Answer : C

Question. Which of these contain vocal cords?
(a) Larynx
(b) Pharynx
(c) Bronchial tube
(d) Glottis

Answer : A

Question. Pleura is double membrane sac which envelops :
(a) Kidneys
(b) Brain
(c) Lungs
(d) Nasal passage

Answer : C

Question. The movement of true vocal cords in man is controlled by cartilages :
(a) arytenoids
(b) cricoid
(c) thyroid
(d) both (a) and (b)

Answer : A

Question. Mammalian lungs contain an enormous number of minute alveoli. This is to allow :
(a) more space for increasing the total volume of inspired air
(b) more surface area for diffusion of gases
(c) more spongy texture for keeping lungs in proper shape
(d) more nerve supply to keep, the organs working more efficiently

Answer : B

Question. Even when there is no air in it, human trachea does not collapse due to presence of :
(a) Bony rings
(b) Turgid pressure
(c) Chitinous rings
(d) Cartilaginous rings

Answer : D

Question. Oxygen carried in inhalation ultimately reaches
(a) Bronchioles
(b) Bronchus
(c) Trachea
(d) Alveoli

Answer : A

Question. Adam's Apple represents
(a) Arytenoid cartilage of larynx
(b) Cricoid cartilage of larynx
(c) Thyroid cartilage of larynx
(d) All the above

Answer : C

Question. Number of alveoli in the two human lungs is
(a) 600-800 million
(b) 200 - 300 million
(c) 1- 2 million
(d) 100,000 -150,000

Answer : B

Question. Adam’s Apple corresponds to
(a) Epiglottis
(b) Trachea
(c) Larynx
(d) Thyroid

Answer : C

Question. Which one of the following statements is incorrect
(A) Trachea divides at the level of 5th thoracic vertebra into a right and left primary bronchi.
(B) Initial bronchioles are supported by complete cartilaginous rings.
(C) Each terminal bronchiole gives rise to a number of very thin, irregular walled and vascularised bag-like structure called bronchi.
(D) Larynx is a cartilaginous box which help in sound production and hence called the sound box.
(a) A only
(b) (B) and (C) only
(c) A, D and C
(d) B, C and D

Answer : B

Question. Diaphragm present in mammals is
(a) Membrane between external and middle ear
(b) Membrane around the brain
(c) Partition between the thoracic and abdominal cavities
(d) Membrane around lungs

Answer : C

Question. 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 and endocrine gland
(d) Scurvy is due to vitamin C deficienc

Answer : B

Question. Trachea is lined with incomplete rings of
(a) Fibrous cartilage
(b) Calcified cartilage
(c) Elastic cartilage
(d) Hyaline cartilage

Answer : D

Question. Which one protects the lungs?
(a) Ribs
(b) Vertebral column
(c) Sternum
(d) All the above

Answer : D

Question. In lungs, air is separated from venous blood by
(a) Squamous epithelium + tunica externa of blood vessel
(b) Squamous epithelium + endothelium of blood vessel
(c) Transitional epithelium + tunica media of blood vessel
(d) Columnar epithelium + 3 layered wall of blood vessel

Answer : B

Question. Which is the correct sequence of the air passage in man?
(a) Nasal cavity → pharynx → trachea → larynx → bronchi → bronchioles → alveoli
(b) Nasal cavity → pharynx → larynx → trachea → bronchi → bronchioles → alveoli
(c) Nasal cavity → larynx → pharynx → trachea → bronchi → bronchioles → alveoli
(d) Nasal cavity → larynx → bronchi → pharynx → trachea → bronchioles → alveoli

Answer : B

Question. Speciality common in the alveoli of lungs and villi of intestine in mammals is that both :
(a) provide a large surface area
(b) have ciliated epithelium
(c) are suited for diffusion of gases
(d) have rich supply of blood vessels and lymph ducts

Answer : A

Question. Sites of gaseous exchange in lungs are:
(a) tracheioles
(b) alveoli
(c) bronchioles
(d) pulmonary chambers

Answer : B

Question. Intercostal muscles are found attached with :
(a) pelvic cavity
(b) ribs
(c) space between fingers
(d) digits

Answer : B

Question. During inspiration, air passes into lungs due to
(a) Increase in volume of thoracic cavity and fall in lung pressure
(b) Fall in pressure inside the lungs
(c) Increased volume of thoracic cavity
(d) Muscular expansion of lungs

Answer : A

Question. Rate and depth of respiration shall increase when
(a) Oxygen concentration increases
(b) CO₂ concentration increases
(c) Bicarbonate concentration increases
(d) Bicarbonate concentration decreases

Answer : B

Question. If the CO₂ concentration in the blood increases, the breathing shall
(a) Increase
(b) Decrease
(c) Stop
(d) No affect.

Answer : A

Question. The process of respiration is concerned with
(a) Intake of O₂
(b) Liberation of O₂
(c) Liberation of CO₂
(d) Liberation of energy

Answer : D

Question. During inspiration, the diaphragm:
(a) relaxes to become dome-shaped
(b) contracts and flattens
(c) expands
(d) shows no change

Answer : B

Question. Rate of breathing in an adult human is:
(a) 10-12/min
(b) 12-16/min
(c) 20-25/min
(d) 25-30/min

Answer : B

Question. The structure which does not contribute to the breathing movements in mammals is :
(a) Larynx
(b) Ribs
(c) Diaphragm
(d) Intercostal muscles

Answer : A

Question. In expiration, diaphragm becomes
(a) Flattened
(b) Relaxed
(c) Straightened
(d) Arched

Answer : B

Question. Breathing rate is lowest while we are:
(a) Playing tennis
(b) Delivering orders
(c) Eating
(d) Sleeping

Answer : D

Question. Which is the site of actual diffusion of O₂ and CO₂ between blood and atmospheric air ?
(a) Exchange part of respiratory system
(b) Conducting part of respiratory system
(c) Inner pleural membrane.
(d) Alveoli

Answer : A

Question. Tidal volume in human beings is
(a) 1000 ml
(b) 1500 ml
(c) 500 ml
(d) 4.5 litres

Answer : C

Question. Vital capacity of lungs is
(a) 500 ml
(b) 3.5 – 4.5 L
(c) 2.5 – 3.9 L
(d) 1.5 – 2.5 L

Answer : B

Question. Vital capacity of lung is equal to
(a) IRV + ERV + TV
(b) IRV + ERV + TV -RV
(c) IRV + ERV + TV + RV
(d) IRV + ERV

Answer : A

Question. Residual volume in the lungs of an average human is
(a) 500 ml
(b) 3-4·5Iitres
(c) 1000 ml
(d) 1500 ml

Answer : D

Question. Vital capacity of lungs of an average human is
(a) 3000-4500 ml
(b) 1500-.1800 ml
(c) 2000-2500 ml
(d) 500-1000 ml

Answer : A

Question. The amount of air that moves in and out of the lungs, with each normal inspiration and expiration is called
(a) Residual volume
(b) Vital capacity
(c) Tidal volume
(d) Tidal capacity.

Answer : C

Question. Residual air mostly occurs in
(a) Alveoli
(b) Bronchus
(c) Nostrils
(d) Trachea

Answer : A

Question. About 1200 ml of air left in lungs is called
(a) Tidal volume
(b) Inspiratory reserve volume
(c) Residual volume
(d) Vital capacity

Answer : C

Question. Dead space is
(a) Upper respiratory tract
(b) Nasal chambers
(c) Alveolar space
(d) Lower respiratory tracl

Answer : A

Question. 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) The two are variable

Answer : B

Question. Volume of air inspired and expired in each breath in normal respiration by man is called :
(a) Tidal volume
(b) Total lung capacity
(d) Inspiratory capacity
(d) Residual volume

Answer : A

Question. Volume of air remaining in lungs after maximal expiratory effort is :
(a) Vital capacity
(b) Total lung capacity
(c) Tidal volume
(d) Residual volume

Answer : D

Question. Partial pressure of oxygen in the inspired and expired air is respectively
(a) 158 and 116 mm Hg
(b) 158 and 40 mm Hg
(c) 100 and 95 mm Hg
(d) 40 and 95 mm Hg

Answer : A

Question. Oxyhaemoglobin dissociates at
(a) Low O₂ P in tissues
(b) High O₂ P in tissues
(c) Equal O₂ P
(d) All times irrespective of O₂ P

Answer : A

Question. In lungs there is definite exchange of ions between RBC and plasma. Removal of CO₂ from blood involves
(a) Influx of Cl– into RBC
(b) Efflux of Na+ from RBC
(c) Influx of HCO₃– ions in RBC
(d) Effllux of HCO₃– ions from RBC

Answer : C

Question. human beings, CO₂ concentration in the inspired and expired air is respectively
(a) 0·03% and 5·3%
(b) 0·4% and 5·0%
(c) 0·04% and 3·0%
(d) 0·03% and 4·0%

Answer : D

Question. Oxygen dissociation curve of myoglobin is
(a) Hypobolic
(b) Hyperbolic
(c) Linear
(d) Sigmoid

Answer : B

Question. During one circuit of blood from lungs to the tissue and back through the circulatory system the percentage of haemoglobin giving the oxygen is
(a) 50%
(b) 25%
(c) 75%
(d) 100%

Answer : B

Question. Which of the following gases makes the most stable combination with the haemoglobin of red blood cells ?
(a) CO₂
(b) CO
(c) O₂
(d) N₂

Answer : B

Question. Oxygen is transported in vertebrates as
(a) Dissolved in plasma
(b) Complex with haemoglobin
(c) Dissolved in cytoplasm of erythrocytes
(d) Absorbed over the RBC.

Answer : B

Question. Bicarbonate ion is produced inside
(a) Lymphocytes
(b) Erythrocytes
(c) Neutrophils
(d) Basophils

Answer : B

Question. Blood cells possess CO₂ in the form
(a) NaHCO₃
(b) H₂CO₃
(c) Hb-CO₂
(d) Hb-CO₂ and Hb-CO

Answer : C

Question. Exchange of O₂ and CO₂ at the respiratory surface occurs through
(a) Facilitated transport
(b) Active transport
(c) Osmosis
(d) Diffusion.

Answer : D

Question. Myoglobin is found in
(a) Lungs
(b) Blood
(c) Muscles
(d) Red blood corpuscles

Answer : C

Question. What would happen when blood is acidic ?
(a) Binding of oxygen with haemoglobin Increases
(b) Red blood corpuscles are formed in higher number
(c) Binding of oxygen with haemoglobin decreases
(d) There is no change in oxygen binding nor number of RBC

Answer : C

Question. Dissociation curve is connected with
(a) Carbonic anhydrase
(b) Carbon dioxide
(c) Oxygen
(d) Oxyhaemoglobin

Answer : D

Question. Hamburger's phenomenon is also known as
(a) HCO–₃ shift
(b) Na+ shift
(c) H+ shift
(d) Chloride shift

Answer : D

Question. Oxygen carrying capacity of blood is
(a) 20%
(b) 30%
(c) 40%
(d) 50%

Answer : A

Question. Chloride shift is required for transport of
(a) Nitrogen
(b) Oxygen
(c) Carbon dioxide
(d) Carbon dioxide and oxygen

Answer : C

Question. Oxygen haemoglobin dissociation curve will shift to right on decrease of
(a) Acidity
(b) Carbon dioxide concentration
(c) Temperature
(d) pH

Answer : D

Question. Maximum amount 70-75% of carbon dioxide transport occurs as
(a) Dissolved in plasma
(b) Carbaminohaemoglobin complex
(c) Bicarbonate
(d) None of the above

Answer : C

Question. Haldane believes oxyhaemoglobin to act as
(a) Acid
(b) Alkali
(c) Buffer
(d) None of the above

Answer : A

Question. Percentage of oxygen transported by haemoglobin is
(a) 97%
(b) 100%
(c) 49%
(d) 3%

Answer : A

Question. Compound soluble in water which does not impede oxygen transportation is
(a) SO₂
(b) SO₃
(c) CO
(d) NO

Answer : A

Question. Air entering lungs is
(a) Warmed (b) Filtered (c) Deprived of some oxygen (d) Enriched with CO₂ What is true ?
(a) 1, 2, 3 and 4
(b) 1 and 2
(c) 2 and 4
(d) 2 and 3

Answer : B

Question. One molecule of haemoglobin carries
(a) One molecule of O₂
(b) Two molecules of O₂
(c) Three molecules of O₂
(d) Four molecules of O₂

Answer : D

Question. Gaseous exchange between blood and alveolar air across respiratory membrane occurs by:
(a) Osmosis
(b) Diffusion
(c) Active transport
(d) Phagocytosis

Answer : B

Question. How is oxygen mainly transported by blood in man?
(a) adsorbed to the surface of RBCs
(b) combined with haemoglobin
(c) dissolved in plasma
(d) all the above ways

Answer : B

Question. During oxygen transport the oxyhaemoglobin at the tissue level liberates oxygen to the cells because in tissue :
(a) O₂ concentration is high and CO₂ is low
(b) O₂ concentration is low and CO₂ is not high
(c) O₂ tension is high and CO₂ tension is low
(d) O₂ tension is low and CO₂ tension is high

Answer : D

Question. The blood leaving the lungs has all its haemoglobin oxygenated and gives up oxygen to the tissues, because:
(a) The tissue can absorb O₂ from oxyhaemoglobin
(b) O₂ concentration in tissues is lower and CO₂ concentration higher than in lungs
(c) O₂ concentration in tissues is higher and CO₂ concentration lower than in lungs
(d) Oxyhaemoglobin undergoes reduction

Answer : B

Question. Oxygen carrier or the respiratory pigment in the blood of frog and other vertebrates is :
(a) Haemocyanin
(b) Cytochrome
(c) Haemoglobin
(d) None of these

Answer : C

Question. When, under certain conditions, the P50 value of haemoglobin rises the affinity of the pigment of combining with O₂ will :
(a) remain same
(b) rise
(c) fall
(d) first rise and then fall

Answer : C

Question. If, under certain conditions, the P50 value of haemoglobin rises to 100 mm Hg, a person will die of O₂ deficiency because the pigment:
(a) is not loading enough oxygen in lungs
(b) can load enough oxygen in lungs but cannot unload it in tissues
(c) can neither load nor unload oxygen
(d) suffers dehydration and cannot function normally

Answer : C

Question. Under a given oxygen concentration in blood, dissociation of oxyhaemoglobin will increase if.
(a) pH of blood falls
(b) pH of blood rises
(c) CO₂ concentration in blood falls
(d) Free fatty acid concentration in blood falls

Answer : A

Question. When partial pressure of CO₂ (PCO₂) rises, the oxygen dissociation curve of haemoglobin at 37^oC will :
(a) shift towards right
(b) shift towards left
(c) become irregular
(d) remain unchanged

Answer : A

Question. Amount of O₂ normally carried by 100 mL of pure blood :
(a) 10 rnL
(b) 20 mL
(c) 30 mL
(d) 40 mL

Answer : B

Question. In the process of transport of CO₂ which phenomenon occurs between RBCs and plasma?
(a) Osmosis
(b) Adsorption
(c) Chloride shift
(d) Absorption

Answer : C

Question. Haemoglobin-oxygen dissociation curve is :
(a) Hyperbolic
(b) Sigmoid
(c) Straight
(d) Constant

Answer : B

Question. Exchange of gases between blood and alveolar air in lungs occurs by :
(a) Active transport
(b) Simple diffusion
(c) Osmosis
(d) All of these

Answer : B

Question. In which condition, oxygen dissociation curve of haemoglobin shift to right of normal curve ?
(a) decrease in pH
(b) decrease in CO₂ concentration
(c) decrease in acidity
(d) decrease in temperature

Answer : A

Question. O₂ content of air we expire is :
(a) 4%
(b) 20%
(c) 25%
(d) 16%

Answer : D

Question. The percentage of O₂ in inhaled air is about :
(a) 21%
(b) 16%
(c) 79%
(d) 4%

Answer : A

Question. The largest amount of CO₂ is transported by the blood as :
(a) CO₂ in the plasma
(b) H₂CO₃ in the plasma
(c) Bicarbonate ions in plasma
(d) Bicarbonate ions in the erythrocytes

Answer : C