Important Questions of Class 10 Biology Chapter 1 – Life Process

Prepare Class 10 Biology chapter 1 on the topic Life process, with us. In this blog, we provide you with the most important questions for practice. For quick revision refer to these questions. It is framed in such a way that it will save you time and give you a conceptual clarity.

Life Process Questions:

  1. Why is nutrition necessary for organism?

Ans.    Nutrition is required for:

(i)         Acquiring energy for various metabolic processes of the body.

(ii)        Growth of new cells.

(iii)       Repair of worn out cells.

(iv)       Developing resistance against diseases.

  1. Write the basic steps involved in the process of photosynthesis.

      Ans. 1. Absorption of solar energy by chlorophyll.

  1. Splitting of water molecule to form hydrogen and oxygen.
  2. Reduction of CO2 to carbohydrates.
  1. Explain the process of digestion in stomach and small intestine.

Ans. Digestion in stomach:- Gastric glands present in stomach secrete gastric juice which contains HCl, pepsin, etc. makes the food soft, activates the pepsin & kills the micro organism if present in the food. Pepsin acts on proteins & break it into peptones.

Digestion in small intestine:-In intestine, acidic food coming from stomach is converted into alkaline with the help of bile secreted by liver and pancreatic juice. In alkaline medium digestive enzymes of pancreas & small intestine act on food & complete the digestion by converting protein into amino acids, carbohydrates into glucose & fats into fatty acids & glycerol.

  1. What is the role of bile juice?

Ans.    Bile juice is alkaline in nature and possesses bile salts and pigments. This helps to neutralize the acidic food coming from stomach so that the pancreatic enzymes may act on it. Bile salts also help in the emulsification of fats by which larger fat globules are converted into smaller ones.

  1. Explain the breakdown of glucose by various pathways.

Ans.

Important Questions of Class 10 Biology Chapter 1 - Life Process 1

  1. Explain the mechanism of breathing.

Ans.    It includes two steps:

(a)        Inhalation:

  1. Diaphragm lowers down/ contracts.
  2. External inter-costal muscle contracts.
  3. Enlargement of thoracic/ chest cavity.
  4. Reduction of air pressure inside lungs.
  5. Air rushes in.

(b)       Exhalation

  1. Diaphragm relaxes.
  2. Thoracic cavity comes back to original size.
  3. External inter-costal muscle relaxes.
  4. Air pressure increases inside lungs.
  5. Air rushes out.
  1. What is difference in transportation done by xylem and phloem?

Ans.    (i)         Transport in xylem could be explained by normal physical forces, whereas the translocation in phloem is achieved by utilizing energy.

            (ii)        The movement of water (and dissolved salts) in xylem is always upwards (from soil to leaves, unidirectional) whereas the movement of food in phloem (or translocation) can be in both upward and downward direction (bidirectional).

  1. Write down the difference between Artery & Vein.
Ans. Artery Vein
Thick & elastic. Thin & non – elastic.
Lumen is narrow. Lumen is wide.
Carries blood away from heart. Carries blood towards heart.
Carries oxygenated blood except pulmonary artery. Carries deoxygenated blood except pulmonary vein.
Mostly located in deeper part of body. Mostly located superficially.
Valves are absent. Valves are present.
Blood flows with high speed & jerk. Blood flows with low speed & smoothly.
  1. What is the normal systolic and diastolic pressure in humans? Name the instrument used for its measurement.

Ans.    Systolic pressure : 120 mm of Hg.

Diastolic pressure : 80 mm of Hg.

Sphygmomanometer is the instrument used for measuring blood pressure.

  1. Why the blood circulation in human heart is called double circulation?

Ans.    The blood passes through the heart twice before reaching the body parts. It involves:

            (a)        Systemic Circulation: Oxygenated blood flows from heart to body parts and deoxygenated blood back to heart.

            (b)       Pulmonary Circulation: Deoxygenated blood flows from heart to lungs and oxygenated blood back to heart.

  1. What is osmoregulation? Explain how kidney plays an important role in osmoregulation.

Ans.    Osmoregulation means to maintain ion concentration and water content in the body.

Kidney can do this function as kidney can produce hypotonic urine (less concentrated in comparison to body fluids) or hypertonic urine (more concentrated in comparison to body fluids) by reabsorption or removal of excess water.

            Re-absorption of water depends on water content and concentration of waste in blood.

  1. Explain physiology of urine formation.

or

Write the main steps of urine formation.

Ans.    Urine is formed in 3 stages-

  1. Ultrafiltration
  2. Selective reabsorption and
  3. Tubular secretion
  4. Ultrafiltration: In this process the blood containing wastes (brought by renal artery) enters glomerulus. Substances like glucose, amino acids, salts, water, urea, etc., get filtered into Bowman’s capsule and then enters the tubule of nephron.
  5. Selective reabsorption: – When the filtrate containing useful substances as well as the waste substances passes through the tubule then glucose, Amino acids, salts, water, etc., are reabsorbed in the blood. Only waste like urea, salts, excess water remain in the tubule.
  6. Tubular secretion: It is the process by which small amount of harmful substances remaining in the blood comes out from the peritubular blood capillaries and enter into the tubular part. Reabsorption of water depends on water content and concentration of excretory waste in the blood.
  1. Write the common features of all respiratory organs.

Ans.  They all have some similar common features:

  1. A large surface area to get enough oxygen.
  2. Thin walls for easy diffusion and exchange of respiratory gases.
  3. Richly supplied with blood for the transport of gases.
  1. Explain why terrestrial plants die when they remain water-logged for a long period?

Ans.    If terrestrial plants remain water logged for a long period, then air amongst soil particles is expelled by water. Thus, O2 is not available to the roots for aerobic respiration. Roots thus respire anaerobically producing alcohol. This may kill the plant.

  1. What is role of mucus?

Ans.    Mucus protects the inner lining of the stomach from the action of the acid under normal conditions. Mucus also lubricates the entire digestive tract.

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