Free Digestion MCQs with Answers
680 Digestion MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The human digestive system covers the organs from mouth to anus, the movement of food, and the mechanical and chemical breakdown of carbohydrates, proteins and fats. It also includes the roles of digestive enzymes, bile, absorption through intestinal villi, and the assimilation of nutrients by body cells.
Last updated
Read the Digestion notesFree MDCAT chapter notes with key terms680 questions · page 26 of 34
- A. Oxygen
- B. Bicarbonate
- C. Carbon diaoxide
- D. Carbon monooxide
Explanation: Bicarbonate (HCO3-) is an important molecule involved in the regulation of blood pH.
Correct answer: Bicarbonate- A. 3%
- B. 97%
- C. 70%
- D. 305%
Explanation: 3% of oxygen is transported by plasma while the rest 97% is transported by red blood cells.
Correct answer: 3%- A. Ventilation
- B. Gas transport
- C. Photorespiration
- D. Respiration
Explanation: Ventilation refers to the process of bringing oxygenated air into contact with a gas exchange surface, such as the lungs in humans or the…
Correct answer: Ventilation- A. Mucosa
- B. Cutaneous
- C. Tracheal
- D. Pulmonary
Explanation: The mode of respiration in mammals is pulmonary because they rely on specialized respiratory organs, such as the lungs, to facilitate the…
Correct answer: Pulmonary- 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
Explanation: Nasal cavity→Pharynx→larynx →trachea →bronchi→bronchioles→alveoli This is the correct order. Hence, option B is correct.
Correct answer: Nasal cavity→Pharynx→larynx →trachea →bronchi→bronchioles→alveoli- A. Vital capicity
- B. Total lung Capicity
- C. Tidal Capicity
- D. Functional residual capacity
Explanation: Total lung capacity is the volume in the lungs after a maximum effort of inspiration, and so is the total amount of air the lungs can…
Correct answer: Total lung Capicity- A. Thecodont
- B. Diphyodont
- C. Heterodont
- D. Lophodont
Explanation: Heterodont is the correct term. It refers to animals, including humans, that have different types of teeth with specialized functions.
Correct answer: Heterodont- A. I2, , C2 , P1 ,M3
- B. I3 , C1 , P2 , M2
- C. I2 , C1 , P2 , M3
- D. I2 , C2 ,P3 ,M1
Explanation: The dental formula for adult human beings is 2123/2123. There are 2 incisors, 1 canine, 2 premolars aand 3 molars in one row.
Correct answer: I2 , C1 , P2 , M3- A. Sphincter of Boyden
- B. Sphincter of Oddi
- C. Hepatopancreatic ampulla
- D. Cardiac sphincter
Explanation: The sphincter of Oddi is the muscular valve surrounding the exit of the bile duct and pancreatic duct into the duodenum
Correct answer: Sphincter of Oddi- A. 4
- B. 6
- C. 5
- D. 7
Explanation: The enzymes that are secreted by the pancreas from the list are; Trypsinogen, Amylase, Lipase, Chymotrypsinogen, Procarboxypeptidase, and…
Correct answer: 6- A. Bacterial infection
- B. Viral infection
- C. Infection of intestinal parasites ( e.g., different types of worms)
- D. All of the above
Explanation: Certain bacteria, such as Salmonella, Escherichia coli (E. coli), and Campylobacter, can infect the intestines and lead to inflammation…
Correct answer: All of the above- A. 12cm
- B. 15cm
- C. 18cm
- D. 20cm
Explanation: The human windpipe is 12 cm (precisely 11.8cm) in length.
Correct answer: 12cm- A. Emphysema
- B. Pneumonia
- C. Asthma
- D. Bronchitis
Explanation: Bronchitis is the inflammation of the mucous membrane in the bronchial tubes. It typically causes bronchospasm and coughing.
Correct answer: Bronchitis- A. Histamine
- B. Heparin
- C. Epinephrine
- D. Antibodies
Explanation: Histamine is released by mast cells, which are a type of blood cell involved in allergic reactions.
Correct answer: Histamine515. Which organ of plant has functions of anchoring, storage of food, absorbing water and minerals:
- A. Shoot
- B. Leaves
- C. Flowers
- D. Root
Explanation: Roots anchor the plant in the soil, providing stability and support. Some plants store food in their roots, such as carrots and radishes.
Correct answer: Root- A. Transpiration pull
- B. Capillarity
- C. Molecular adhesion
- D. Photosynthesis
Explanation: In woody plants, the primary mechanism responsible for the ascent of sap is the transpirational pull.
Correct answer: Transpiration pull- A. Capillarity
- B. Roll of atmospheric pressure
- C. Pulsating action of' living cells
- D. Transpiration cohesion theory of Dixon
Explanation: The transpiration cohesion theory states that water molecules in the xylem of a tree are held together by cohesion, or the attraction…
Correct answer: Transpiration cohesion theory of Dixon- A. Venus fly trap
- B. Sundew
- C. Cuscuta
- D. Pitcher plant
Explanation: Cuscuta is a parasitic plant that does not have chlorophyll and cannot produce its own food.
Correct answer: Cuscuta- A. Chlorophyll
- B. Stem
- C. Fruit
- D. Roots
Explanation: Chlorophyll is a green pigment that is found in the leaves of plants. It absorbs sunlight and uses it to convert carbon dioxide and water…
Correct answer: Chlorophyll- A. Wall pressure
- B. Suction pressure
- C. Osmotic pressure
- D. Turgor pressure
Explanation: The pressure exerted by the swelling protoplast on the walls of the cell is called turgor pressure.
Correct answer: Turgor pressure