Important Questions for Class 10 Science Chapter 6 – Life Processes

Below are some important questions for class 10 science chapter 6 – Life Processes that students must study thoroughly.Have you ever taken a moment and wondered how life exists? The existence of life on Earth is primarily based on certain functions and processes, termed Life Processes. These are certain basic critical processes that are essential for keeping an organism healthy and for the proper functioning of the body’s organ systems. These essential life processes include nutrition, transport, metabolism, respiration, reproduction, and excretion and contribute to organisms’ maintenance. They are fundamental for plants, animals, and humans to survive. There are some additional requirements in humans, the most complex form of life, such as digestion, excretion, growth, and differentiation and all of these processes are linked.

Some important questions topics for class 10 science chapter 6 – Life Processes are:

• Nutrition
• Metabolism
• Respiration
• Reproduction
• Excretion
• Transportation

Below are some of the important questions for class 10 science chapter 6 – Life Processes from an examination point of view.

Class 10 Science Important Questions Chapter 6 – Life Processes

Q1. (a) Why is nutrition necessary for the human body?

(b) What causes movement of food inside the alimentary canal?

(c) Why is small intestine in herbivores longer than in carnivores?

(d) What will happen if mucus is not secreted by the gastric glands?

Solution:

(a) Human body continuously require energy for their life activities like respiration, circulation, excretion, etc. Energy is required even we are sleeping because a number of biological processes keep on occurring. All these processes require energy and this energy is obtained from nutrition. Nutrition is also needed for growth and repair of human body.

(b) The wall of alimentary tract contains muscles which can contract and expand alternately. The contraction and expansion movement of the walls of foodpipe is called peristaltic movement. The peristaltic movement moves the partially digested food in all the digestive organs throughout the alimentary canal.

(c) Herbivores eat plants which is rich in cellulose. Cellulose takes longer time for complete digestion by the enzymes present in symbiotic bacteria. Therefore, they have longer small intestine. Carnivores, feed on flesh which is easier to digest and do not contain cellulose also. Therefore, they have shorter intestine for digestion of food eaten by them.

(d) Gastric glands secrete HCl, mucus, rennin and pepsin enzymes. Mucus protects the inner lining of stomach from the action of HCl and enzymes. In the absence of mucus, there would be erosion of inner lining of stomach leading to acidity and ulcers.

Q2. Most of the digestion and absorption of the food takes place in the

(a) small intestine

(b) liver

(c) stomach

(d) large intestine.

Solution:

(a) small intestine

Q3. Name the glands present in the wall of the stomach that release secretions for digestion of food. Write the three components of secretion that are released by these glands.

Solution:

Stomach’s muscular wall contains gastric glands. These glands secrete gastric juices which contain dilute hydrochloric acid, mucus and two protein digesting enzymes rennin and pepsin.

Q4. Diffusion is insufficient to meet the oxygen requirement of multicellular organisms like human. State reason.

Solution:

Due to higher metabolic rate and the volume of human body is so large that oxygen cannot diffuse into all cells of the body quickly as oxygen will have to travel large distances to reach each and every cell. So diffusion is insufficient to meet the oxygen demand of multicellular organisms.

Q5. Why is there a difference in the rate of breathing between aquatic organisms and terrestrial organisms? Explain

Solution:

Terrestrial organisms inspire atmospheric oxygen, while aquatic organisms thrive on the dissolved oxygen present in water. Air contains about 21% of oxygen while water has less than 1% oxygen in dissolved state. Oxygen diffuses through water at a much slower rate as compared to air. A terrestrial organism has the advantage of utilising greater amount of oxygen at a faster rate with lesser effort whereas, aquatic organisms have to put more effort to obtain the same amount of oxygen, therefore breathing in aquatic organisms is much faster than the terrestrial organisms.

Q6. State reasons for the following:

(i) Herbivores need a longer small intestine while carnivores have shorter small intestine.

(ii) The lungs are designed in human beings to maximise the area for exchange of gases.

Solution:

(i) Herbivores need a longer small intestine than that of carnivores because their diet is mostly grass and plants, that contains more fibres and cellulose which are hard to digest. Longer small intestine also hosts many small bacteria that process and break down cellulose into glucose which is a source of energy. Carnivores diet is not rich in cellulose so, they do not need to harbour bacteria for cellulose digestion.

(ii) Human lungs have a highly branched network of respiratory tubes. A primary bronchus divides into secondary bronchus, which in turn forms tertiary bronchus. Tertiary bronchus divides repeatedly into bronchioles which finally terminate into alveoli. Alveoli are small, rounded polyhedral pouches which are extremely thin- walled and possess a network of capillaries, for the exchange of gases. Due to vast surface area of alveoli, exchange of gases becomes a fast and effective process. Oxygen diffuses from alveoli into pulmonary blood capillaries and CO2 diffuses out from capillaries into alveoli.

Q7. Write three types of blood vessels. Give one important feature of each.

Solution:

The three types of blood vessels in human body are: (i) arteries, (ii) veins and (iii) capillaries.

(i) Arteries are the blood vessels which carry blood from heart to various parts of the body. The walls of arteries are thick, elastic and muscular that enables them to dilate but not rupture when the heart contracts and forces blood into them.

(ii) Veins are thin walled blood vessels which bring blood from the body back to the heart. They are larger and hold more blood than the arteries. The lumen of veins are provided with valves to prevent the backflow of blood.

(iii) Capillaries are thin walled and extremely narrow blood vessels which occur at the terminals of artery and vein. The wall of capillaries are permeable to water and dissolved substances so that the exchange of materials between the blood and body cells can take place.

Q8. Explain how the translocation of materials in phloem tissue in plants is achieved by utilising energy.

Solution:

The phloem cells transport the soluble food materials to all parts of plant. The transport of food from leaves to different parts of plant is termed as translocation. Components of phloem are sieve tubes, companion cells, phloem parenchyma and phloem fibres. The food is manufactured in the mesophyll cells (or photosynthetic cells) of a leaf. The manufactured food enters into sieve tubes of the phloem and is transported as a dilute aqueous solution either in upward or downward direction. Food is transported to all non-green parts of the plant for their growth and metabolic activities. Besides food molecules, phloem also transports amino acids, hormones synthesised in the shoot tips and root tips and other metabolites.

In this process, glucose is transferred to phloem tissue using energy from ATP. This increases the osmotic pressure of the tissue causing the water to move into it (endosmosis). Soluble material is then transferred from phloem tissue to other tissues which have less pressure than in the phloem. Thus, according to plants requirement, the material is translocated from higher osmotic pressure areas to lower osmotic pressure areas.

Q9. What do the following transport?

(i) Xylem

(ii) Phloem

(iii) Pulmonary vein

(iv) Vena cava

(v) Pulmonary artery

(vi) Aorta 

Solution:

(i) Xylem is a specialised plant conducting tissue that transports water and minerals from roots to all aerial parts of plants which occurs against gravitational force with the help of ascent of sap.

(ii) Phloem transports food that is prepared in the leaves, through photosynthesis, to various parts of plant. This process is called translocation. Phloem also transports amino acids, hormones synthesised in the shoot tips and root tips and other metabolites.

(iii) Pulmonary vein present in human circulatory system brings oxygenated blood from lungs to the left atrium of heart.

(iv) Vena cava transport deoxygenated blood collected by all veins of body except pulmonary vein and pass it to the right atrium of heart.

(v) Pulmonary artery transports deoxygenated blood from right atrium of heart to lungs for oxygenation.

(vi) Aorta transports oxygenated blood from left atrium to systemic arteries which further take the blood to various body parts and organs.

Q10. (a) Mention any two components of blood.

(b) Trace the movement of oxygenated blood in the body.

(c) Write the function of valves present in between atria and ventricles.

(d) Write one structural difference between the composition of artery and veins.

Solution:

(a) Two components of blood are blood plasma and blood corpuscles.

(b) Deoxygenated blood gets oxygenated in the lungs, from there it moves to heart and pumped to different parts of the body. Its path can be traced out as

Lungs → Pulmonary veins → Left atrium of heart → Aorta → Arteries → Body parts

(c) When blood is pumped, valves prevent back flow of blood between ventricles and atria. They open and allow the right amount of blood to flow from one chamber to the other.

(d) Structural difference between veins and arteries is as follows:

Veins:

Veins have thin, less elastic and less muscular walls. They have valves to prevent back flow of blood.

Arteries:

Arteries have thick, elastic and muscular walls with no valves.