ROUTERA

Life Processes

Class 10th Science Chapter Assertion and Reason

Life Processes

  • Options:
    a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
    b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
    c) Assertion (A) is true, but Reason (R) is false.
    d) Assertion (A) is false, but Reason (R) is true.

 

Question 1

Assertion (A): The process of respiration occurs in all living organisms.
Reason (R): Respiration is necessary for obtaining energy to perform life processes.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: All living organisms require energy to carry out life processes, and respiration provides the energy needed by breaking down glucose.

Question 2

Assertion (A): In photosynthesis, plants convert light energy into chemical energy.
Reason (R): Chlorophyll is the pigment responsible for absorbing light energy during photosynthesis.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Chlorophyll absorbs sunlight, enabling plants to convert light energy into chemical energy stored in glucose during photosynthesis.

Question 3

Assertion (A): The heart pumps blood throughout the body.
Reason (R): Blood carries nutrients and oxygen to the cells and removes waste products.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The heart's pumping action is essential for circulation, delivering oxygen and nutrients while collecting waste products for excretion.

Question 4

Assertion (A): Aerobic respiration is more efficient than anaerobic respiration.
Reason (R): Aerobic respiration occurs in the presence of oxygen and produces more ATP.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Aerobic respiration yields more ATP (energy) per molecule of glucose than anaerobic respiration because it fully oxidizes glucose.

Question 5

Assertion (A): Digestion starts in the mouth.
Reason (R): Saliva contains enzymes that begin the breakdown of carbohydrates.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Saliva contains the enzyme amylase, which initiates the digestion of carbohydrates as soon as food enters the mouth.

Question 6

Assertion (A): The stomata are responsible for gas exchange in plants.
Reason (R): Stomata allow carbon dioxide to enter and oxygen to exit during photosynthesis.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Stomata are tiny openings on the leaf surface that facilitate the exchange of gases necessary for photosynthesis and respiration.

Question 7

Assertion (A): The process of transpiration is important for plants.
Reason (R): Transpiration helps in nutrient absorption and cooling of the plant.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Transpiration creates a negative pressure that helps draw water and nutrients from the roots while cooling the plant through evaporative cooling.

Question 8

Assertion (A): Lungs are the primary organs for respiration in humans.
Reason (R): Lungs facilitate gas exchange between the air and blood.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The lungs are responsible for taking in oxygen and expelling carbon dioxide, essential for aerobic respiration.

Question 9

Assertion (A): In plants, nitrogen is essential for protein synthesis.
Reason (R): Nitrogen is a key component of amino acids, which make up proteins.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Amino acids contain nitrogen, and proteins are composed of chains of amino acids, making nitrogen essential for protein synthesis.

Question 10

Assertion (A): Blood is considered a connective tissue.
Reason (R): Blood consists of cells suspended in a liquid matrix called plasma.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The structure of blood, with its cellular components and liquid plasma, classifies it as a connective tissue in the body.

Question 11

Assertion (A): Fermentation is a type of anaerobic respiration.
Reason (R): Fermentation occurs in the absence of oxygen and produces lactic acid or alcohol.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Fermentation occurs when oxygen is not available, leading to the conversion of sugars into lactic acid or alcohol, generating energy.

Question 12

Assertion (A): Plants obtain water mainly through their roots.
Reason (R): Roots are adapted to absorb water from the soil efficiently.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Roots have specialized structures, such as root hairs, that increase surface area for water absorption from the soil.

Question 13

Assertion (A): The process of respiration is a biochemical process.
Reason (R): Respiration involves the conversion of glucose into energy through chemical reactions.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Respiration consists of a series of chemical reactions that break down glucose to release energy stored in its bonds.

Question 14

Assertion (A): The heart has four chambers.
Reason (R): The four chambers of the heart help separate oxygenated and deoxygenated blood.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The four chambers (two atria and two ventricles) allow efficient circulation by keeping oxygenated and deoxygenated blood separate.

Question 15

Assertion (A): The digestive system breaks down food into smaller, absorbable units.
Reason (R): Digestive enzymes play a critical role in the breakdown of complex molecules.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Digestive enzymes catalyze the hydrolysis of macromolecules (carbohydrates, proteins, and fats) into smaller molecules that can be absorbed by the body.

Question 16

Assertion (A): Plants do not require oxygen for respiration during the day.
Reason (R): During the day, plants primarily perform photosynthesis, which produces oxygen.

  • Answer: b) Assertion (A) is false, but Reason (R) is true.
  • Explanation: Plants require oxygen for respiration both day and night, even while photosynthesis produces oxygen during the day.

Question 17

Assertion (A): Insects have a unique respiratory system called tracheae.
Reason (R): Tracheae are tubes that transport oxygen directly to the tissues.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The tracheal system allows efficient oxygen delivery directly to tissues without involving blood, facilitating respiration in insects.

Question 18

Assertion (A): The small intestine is the primary site for nutrient absorption.
Reason (R): The small intestine has a large surface area due to villi and microvilli.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The presence of villi and microvilli increases the surface area of the small intestine, enhancing its ability to absorb nutrients effectively.

Question 19

Assertion (A): The process of digestion is completed in the small intestine.
Reason (R): Enzymes from the pancreas and bile from the liver aid in the digestion of food.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The small intestine is where digestive enzymes and bile act on food, breaking it down into absorbable units.

Question 20

Assertion (A): In plants, phloem is responsible for the transport of food.
Reason (R): Phloem transports nutrients from the leaves to other parts of the plant.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Phloem tissue conducts the synthesized food (mainly sugars) produced during photosynthesis from the leaves to other tissues in the plant.