Grade 11 : Biology - Breathing and Gas Exchange in Animals (Set 4)

Question 1

Organism	Primary Respiratory Structure
Earthworm	Moist Cuticle
Insects	Tracheal Tubes
Aquatic Arthropods	Gills
Reptiles	Lungs

Which of the following organisms relies on cuticular respiration where exchange of gases takes place directly across the moist body surface?

Accepted Answer

C) Earthworms

Answer

A) Insects

Answer

B) Reptiles

Answer

D) Aquatic Arthropods

Question 2

Steps of Respiration:
I. Diffusion of gases across alveolar membrane
II. Pulmonary ventilation (breathing)
III. Diffusion of gases between blood and tissues
IV. Transport of gases by the blood
V. Utilization of $O_2$ by cells for catabolic reactions

What is the correct logical sequence of respiratory steps in humans?

Accepted Answer

B) II → I → IV → III → V

Answer

A) I → II → III → IV → V

Answer

C) II → IV → I → III → V

Answer

D) I → IV → II → III → V

Question 3

Organism	Primary Respiratory Structure
Earthworm	Moist Cuticle
Insects	Tracheal Tubes
Aquatic Arthropods	Gills
Reptiles	Lungs

Based on the table above, what is the partial pressure gradient of $pO_2$ driving oxygen diffusion from the alveoli into the deoxygenated blood of pulmonary capillaries?

Accepted Answer

A) 64 mmHg

Answer

B) 55 mmHg

Answer

C) 40 mmHg

Answer

D) 95 mmHg

Question 4

A healthy adult male undergoes a spirometry evaluation. The measured spirometric parameters are:
Tidal Volume (TV) = 500 mL
Inspiratory Reserve Volume (IRV) = 2500 mL
Expiratory Reserve Volume (ERV) = 1100 mL
Residual Volume (RV) = 1200 mL

Calculate the Vital Capacity (VC) of this individual.

Accepted Answer

D) 4100 mL

Answer

A) 3000 mL

Answer

B) 3600 mL

Answer

C) 4800 mL

Question 5

[Thoracic Cavity Dynamics during Breathing Cycle]

Which muscular actions occur simultaneously to cause inspiration during normal restful breathing?

Accepted Answer

B) Contraction of diaphragm and contraction of external intercostals

Answer

A) Relaxation of diaphragm and contraction of internal intercostals

Answer

C) Contraction of diaphragm and contraction of abdominal muscles

Answer

D) Relaxation of diaphragm and contraction of external intercostals

Question 6

Oxyhemoglobin Dissociation Curve: S-shaped (Sigmoid curve)
% Saturation of Hb vs $pO_2$ (mmHg)

Which of the following biochemical conditions causes a shift of the oxygen-hemoglobin dissociation curve to the RIGHT (lowering Hb affinity for oxygen)?

Accepted Answer

C) High $pCO_2$, high $H^+$ concentration (low pH), high temperature

Answer

A) Low $pCO_2$, low $H^+$ concentration, low temperature

Answer

B) High $pO_2$, low $pCO_2$, high pH

Answer

D) Low $pCO_2$, high $pO_2$, low temperature

Question 7

Carbon dioxide ($CO_2$) is produced by tissue metabolism and transported to the lungs through blood in three distinct forms.

What percentage of total $CO_2$ is transported dissolved in blood plasma, as carbamino-hemoglobin, and as bicarbonate ions ($HCO_3^-$), respectively?

Accepted Answer

A) 7% plasma, $20-25%$ carbamino-hemoglobin, 70% bicarbonate

Answer

B) 70% plasma, $20-25%$ carbamino-hemoglobin, 7% bicarbonate

Answer

C) $20-25%$ plasma, 7% carbamino-hemoglobin, 70% bicarbonate

Answer

D) 3% plasma, 97% carbamino-hemoglobin, 0% bicarbonate

Question 8

[Microscopic Cross-Section of Alveolar-Capillary Membrane]

The diffusion membrane for gas exchange in human lungs consists of three major layers. Which of the following correctly lists these three layers?

Accepted Answer

D) Thin squamous epithelium of alveoli, endothelium of alveolar capillaries, and intervening basement substance

Answer

A) Ciliated columnar epithelium, smooth muscle layer, capillary basement layer

Answer

B) Simple cuboidal epithelium, connective tissue matrix, cartilage ring

Answer

C) Pleural membrane, pericardial membrane, endothelial layer

Question 9

Neural regulation maintains respiratory rhythm adapted to body demands.

Which specialized neural center located in the pons region of the brain can moderate the functions of the respiratory rhythm center by reducing the duration of inspiration?

Accepted Answer

B) Pneumotaxic center

Answer

A) Apneustic center

Answer

C) Corpus callosum

Answer

D) Chemosensitive area of medulla

Question 10

Lung volume assessment parameters:
Expiratory Reserve Volume (ERV) = 1000 mL
Residual Volume (RV) = 1200 mL
Tidal Volume (TV) = 500 mL

What is the Functional Residual Capacity (FRC)?

Accepted Answer

A) 2200 mL

Answer

B) 1700 mL

Answer

C) 2700 mL

Answer

D) 1500 mL

Question 11

$CO_2 + H_2O \xrightleftharpoons{ ext{Enzyme } X} H_2CO_3 \xrightleftharpoons{ ext{Enzyme } X} HCO_3^- + H^+$

Name the enzyme $X$ present in extremely high concentrations in erythrocytes (RBCs) that catalyzes this reversible reaction.

Accepted Answer

C) Carbonic anhydrase

Answer

A) Carboxypeptidase

Answer

B) Hemoglobinase

Answer

D) Lactate dehydrogenase

Question 12

A 55-year-old chronic heavy smoker presents with shortness of breath. Medical imaging reveals loss of elasticity in alveolar walls and destruction of respiratory alveolar surfaces.

Which chronic respiratory disorder is characterized by these pathology reports?

Accepted Answer

A) Emphysema

Answer

B) Asthma

Answer

C) Pneumonia

Answer

D) Silicosis

Question 13

Statement I: Workers in stone-breaking and grinding industries often suffer from lung fibrosis.
Statement II: Long-term exposure to silica and asbestos dust produces inflammation leading to tissue proliferation and serious lung damage.

Evaluate Statements I and II regarding occupational respiratory disorders.

Accepted Answer

B) Both Statement I and Statement II are correct and Statement II explains Statement I

Answer

A) Statement I is correct, but Statement II is incorrect

Answer

C) Statement I is incorrect, but Statement II is correct

Answer

D) Both Statement I and Statement II are incorrect

Question 14

Given parameters for a patient:
$TV = 500 ext{ mL}$
$IRV = 3000 ext{ mL}$
$ERV = 1100 ext{ mL}$
$RV = 1200 ext{ mL}$

Calculate the Total Lung Capacity (TLC).

Accepted Answer

C) 5800 mL

Answer

A) 4600 mL

Answer

B) 5100 mL

Answer

D) 4100 mL

Question 15

Chemical regulation of respiration is mediated by chemoreceptors located near the medulla and in systemic arteries.

Which substances primarily trigger arterial chemoreceptors located in the aortic arch and carotid artery to send signals to the respiratory rhythm center?

Accepted Answer

D) High $pCO_2$ and high $H^+$ concentration

Answer

A) High $pO_2$ and low $CO_2$

Answer

B) Low $H^+$ concentration and high $pO_2$

Answer

C) High $pO_2$ and low temperature

Question 16

Expiratory Capacity (EC) is the total volume of air a person can expire after a normal inspiration.

If a subject has a Tidal Volume (TV) of 500 mL and an Expiratory Reserve Volume (ERV) of 1100 mL, what is their Expiratory Capacity?

Accepted Answer

A) 1600 mL

Answer

B) 600 mL

Answer

C) 2100 mL

Answer

D) 2700 mL

Question 17

Organism	Primary Respiratory Structure
Earthworm	Moist Cuticle
Insects	Tracheal Tubes
Aquatic Arthropods	Gills
Reptiles	Lungs

According to the partial pressure data of $CO_2$, in which direction will $CO_2$ diffuse at the tissue level?

Accepted Answer

B) From tissues (45 mmHg) into blood capillaries (40 mmHg)

Answer

A) From oxygenated blood (40 mmHg) into tissues (45 mmHg)

Answer

C) From alveoli (40 mmHg) into tissue cells

Answer

D) $CO_2$ will not diffuse as equilibrium exists

Question 18

Every 100 mL of oxygenated blood can deliver a specific volume of $O_2$ to tissues under normal physiological conditions.

What volume of $O_2$ is delivered to tissues per 100 mL of oxygenated blood during standard restful conditions?

Accepted Answer

C) 5 mL

Answer

A) 20 mL

Answer

B) 15 mL

Answer

D) 4 mL

Question 19

Every 100 mL of deoxygenated blood delivers a specific amount of $CO_2$ to the alveoli for elimination.

How much $CO_2$ is delivered to the alveoli by every 100 mL of deoxygenated blood?

Accepted Answer

A) 4 mL

Answer

B) 5 mL

Answer

C) 15 mL

Answer

D) 20 mL

Question 20

A clinician attempts to measure all respiratory volumes directly using a simple routine dry spirometer.

Which of the following lung volumes CANNOT be directly measured using a standard spirometer?

Accepted Answer

D) Residual Volume (RV)

Answer

A) Tidal Volume (TV)

Answer

B) Inspiratory Reserve Volume (IRV)

Answer

C) Expiratory Reserve Volume (ERV)

Grade 11 : Biology - Breathing and Gas Exchange in Animals (Set 4)