Assertion & Reason Type Practice Questions: Life Processes - Science Class 10

Direction: The following question consist of two statements - Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
Question 1:
Assertion: Muscles of stomach wall possess thick layers of muscles. 
Reason: These muscles help in mixing the food with the enzymes presents in the alimentary canal.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (a)
Both A and R are true and R is the correct explanation of A. The lining of alimentary canal has muscles that contract rhythmically in order to push the food forward. This is known as peristaltic movement.

Peristaltic movement

Question 2:
Assertion : Respiration is a biochemical process opposite to photosynthesis.
Reason : Energy is released during respiration.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (a)
Both A and R are true and R is the correct explanation of A. Respiration is defined as the process of biochemical oxidation of nutrients at cellular level. It occurs in the presence of specific enzymes at optimum temperature in the cells to release energy for various metabolic activities. Both Reason and Assertion are true and Reason is the correct explanation of Assertion.

Question 3:
Assertion : In plants there is no need of specialised respiratory organs.
Reason : Plants do not have great demands of gaseous exchange.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (a)
Plants, unlike animals, have no specialised organs for gaseous exchange. Gaseous exchange in plants occurs by diffusion through stomata and lenticels. There are various reason for the absence of respiratory organs in plants. Each part of plant takes care of its own gas exchange needs. There is little transport of gases from one part to another. Plants do not require much demands for gas exchange. Thus the distance that gases must diffuse is not large.

Question 4:
Assertion : Walls of the intestine has numerous villi.
Reason : These villi increase the surface area of digestion.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (c)
All the digested food is taken up by the walls of intestine, which has numerous villi. These increase the surface area of absorption. Assertion is true, but Reason is false.

Question 5:
Assertion : Blood pressure is arterial blood pressure. 
Reason : It is measured by sphygmomanometer.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (b)
Blood pressure refers to the lateral pressure exerted on the wall of the artery during blood flow. Blood pressure is measured with the help of an instrument called sphygmomanometer. Normal adult human blood pressure is 120 mm systolic pressure and 80 mm diastolic pressure.

Question 6:
Assertion : The main organ of human excretory system is kidney. 
Reason : Kidneys perform the function of removing excess water and nitrogenous wastes from the body.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (a)
Both A and R are true and R is the correct explanation of A. The main organ of human excretory system is kidney. The major function performed by kidneys is to remove excess water and nitrogenous wastes from blood in the form of urine. Thus, both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Question 7:
Assertion : Humans are not truly aerobic.
Reason : They produce lactic acid nanerobically.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (b)
Both A and R are true but R is not the correct explanation of A. Human are aerobically respiring animals, but sometimes anaerobic respiration takes place in certain tissues like skeletal muscles, which do not get immediately as much oxygen as it requires. Therefore, the muscles respire anaerobically and produce lactic acid from glucose.

Question 8:
Assertion : HCl converts pepsinogen into active enzyme pepsin. 
Reason : Pepsin converts protein into proteoses and peptones.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (b)
Both A and R are true but R is not the correct explanation of A. HCl creates an acidic medium, which facilitates the action of the enzyme pepsin. The active enzyme pepsin converts proteins into proteoses and peptones.

Question 9:
Assertion : Haemoglobin is  the respiratory pigment in human beings. 
Reason : It transports oxygen in the human body.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (a)
Both A and R are true and R is the correct explanation of A. Haemoglobin is the respiratory pigment in human beings. It takes up oxygen from the air in the lungs and carries it to tissues. Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Question 10:
Assertion : Blood of insects is colourless. 
Reason : The blood of insect does not play any role in transport of oxygen.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (b)
Animals use blood to transport various elements, such as water and food, throughout the body. In human beings, blood is also used to carry oxygen from the lungs to the tissues. The oxygen is attached to a substance called hemoglobin, which has a characteristic red color. Insects have blood too, but it is not used to carry oxygen. Instead, oxygen is distributed via an elaborate system of tubes and air sacs. Thus, insect blood does not have hemoglobin and is not red. In general, insect blood is either colorless, pale yellow or green.

Question 11:
Assertion : Human body produces highly toxic substances, which if not eliminated may cause the death. 
Reason : Excretory substance removes nitrogenous waste from the body.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (b)
Both A and R are true but R is not the correct explanation of A. The biological process which involves the removal of harmful metabolic wastes from the body is called excretion. If these harmful wastes are not removed from the body, then it may cause the death of the organisms.

Question 12:
Assertion : Liver is known as the smallest gland of the body. 
Reason : It secretes salivary amylase.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (e)
Both Assertion and Reason are false. Liver is known as the largest gland of the body, which secretes bile juice. Salivary galnds secrete salivary amylase. Both Assertion and Reason are false.

Question 13:
Assertion: Valves are present in the arteries. 
Reason: Arteries carry oxygenated blood from heart to different body parts except pulmonary artery.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (d)
A is false but R is true. Valves are absent in arteries, whereas it is present in veins, which prevent back flow of blood.

Question 14:
Assertion : Haemodialysis can save the life of patients with kidney failure. 
Reason : Waste products like urea can be removed from the blood by haemodialysis.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (a)
Both A and R are true and R is the correct explanation of A. In case of kidney failure, haemodialysis is the process of purifying blood (or removing waste products like urea) by an artificial kidney. This can save the life of the patient.

Question 15:
Assertion : Photosynthesis is an anabolic process. 
Reason : The process of photosynthesis occurs in chlorophyll.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (c)
A is true but R is false. Photosynthesis is an anabolic process as it takes CO₂ and H₂O then assembles them into glucose. The process of photosynthesis occurs in chloroplast.

Question 16:
Assertion : Alveoli contain an extensive network of blood vessels. 
Reason : Alveoli is the site where exchange of gases occurs.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (a)
Both A and R are true and R is the correct explanation of A. The alveoli of lungs are richly supplied with blood and are the sites where exchange of gases ^O 2and CO2h occurs between blood and atmosphere.

Question 17:
Assertion : Plants excrete various waste products during their life processes.
Reason : They produce urea just like humans.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (c)
A is true but R is false. Like human beings and other organisms, plants also excrete various waste products during their life processes. The waste products include gums, CO₂, O₂, resins, rubber, etc. Urea is produced in humans liver and excreted in the form of urine through urethra. Plants do not produce urea. Thus, Assertion is true, but Reason is false.

Question 18:
Assertion : Bile is essential for digestion of lipids. 
Reason : Bile juice contains enzymes.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (a)
Bile juice is produced by the liver. It is stored in gall bladder. It is drained into the duodenum. It helps in the digestion of lipids in small intestine. It has bile salts which helps in the degradation of lipids. They degrade lipids into small fat globules which aids in their subsequent digestion by the  action of pancreatic enzymes.

Question 19:
Assertion : In humans, there is a complex respiratory system. 
Reason : Human skin is impermeable to gases.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (b)
Both A and R are true but R is not the correct explanation of A. Humans need more oxygen to maintain their high metabolic rates. Thus, a complex respiratory system has evolved so as to meet this need.

Question 20:
Assertion: In humans, major amount of water is absorbed by the tubular part of nephron. 
Reason: Absorption of water depends on the dissolved waste to be excreted from the body.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Correct Answer is Option (b)
Both A and R are true but R is not the correct explanation of A. Major amount of water is selectively reabsorbed by the tubular part of nephron in humans. It depends on the amount of excess water present in the body and dissolved waste to be excreted from the body.