All Free Biology MCQs with Answers

• A. Decreased
• B. Increased
• C. Remains same
• D. First increased then decreased

Explanation: "The explanation for this question will be added soon!".

• A. They are opened sacs
• B. They are closed sacs
• C. They are spongy in nature
• D. They are placed in chest cavity

Explanation: "The explanation for this question will be added soon!".

• A. CO2
• B. Temperature
• C. pH of blood
• D. All of the above

Explanation: "The explanation for this question will be added soon!".

• A. Emphysema
• B. Asthma
• C. Lung cancer
• D. Bronchitis

Explanation: "The explanation for this question will be added soon!".

• A. Emphysema
• B. Lung cancer
• C. Tuberculosis
• D. Asthma

Explanation: Emphysema is the breakdown of Alveoli, hence inside of the lungs is damaged in emphysema.

• A. 2
• B. 8
• C. 5
• D. More than 10

Explanation: Recent researches indicate that more than 10 compounds of tar of tobacco smoke are involv in causing cancer.

• A. 1 molecules of oxygen
• B. 2 molecules of oxygen
• C. 3 molecules of oxygen
• D. 4 molecules of oxygen

Explanation: One molecule of oxygen can bind to the iron atom of a heme group, giving each hemoglobin the ability to transport four oxygen molecules.

• A. 1
• B. 2
• C. 3
• D. 4

Explanation: The nasal cavity is divided into three regions: the nasal vestibule, the nasal cavity proper or nasal fossa, and the olfactory region.

• A. 19.6ml/100 ml blood
• B. 25 ml/100 ml blood
• C. 30 ml/100 ml blood
• D. 20 ml/100 ml blood

Explanation: In 100 ml of blood, there is about 15 g of Hb, so that 100 ml of blood has the capacity to bind 20.1 ml of oxygen.

• A. Reduces friction between membranes
• B. Slide easily on one another
• C. Allows membrane to adhere on one another
• D. All of these are correct

Explanation: The pleural cavity aids optimal functioning of the lugs during breathing.

• A. Melanin
• B. Myoglobin
• C. Rhodopsin
• D. Lutein

Explanation: Myoglobin exhibits a higher affinity for oxygen than hemoglobin. Therefore, it is very efficient at extracting oxygen from the blood.

• A. Voice box
• B. Epiglottis
• C. Bronchi
• D. Windpipe

Explanation: The trachea is often called the windpipe. It's a key part of your respiratory system.

• A. 10
• B. 11
• C. 12
• D. 13

Explanation: The ribs are the bony framework of the thoracic cavity. Generally, there are twelve pairs of ribs.

• A. Pharynx
• B. Larynx
• C. Glottis
• D. Nasal cavity

Explanation: The larynx is a cartilaginous segment of the respiratory tract located in the anterior aspect of the neck.

• A. Bronchioles
• B. Larynx
• C. Trachea
• D. Bronchi

Explanation: "The explanation for this question will be added soon!".

• A. 3.5 liters
• B. 2.5 liters
• C. 4 liters
• D. 5 liters

Explanation: Lung capacity or total lung capacity (TLC) is the volume of air in the lungs upon the maximum effort of inspiration.

• A. Inhalation
• B. Exhalation
• C. Both and A and B
• D. Vocal waves

Explanation: Inhalation is a part of breathing where the air is taken into the lungs by creating negative pressure by the contraction of respiratory…

• A. Alveoli
• B. Trachea
• C. Bronchi
• D. None of these

Explanation: The diaphragm is a muscle that helps you inhale and exhale (breathe in and out).

• A. Pharynx
• B. Diaphragm
• C. Bronchi
• D. None of these

Explanation: The diaphragm is a muscle that helps you inhale and exhale (breathe in and out).

• A. Intercostal muscles
• B. Ribs
• C. Both and A and B
• D. Diaphragm

Explanation: The diaphragm is a muscle that helps you inhale and exhale (breathe in and out).