Very Short Questions -Class 10 -Science- Biology-Chapter 5 – Life Processes

Class 10 -Science-Very Short Questions – Biology-Chapter 5 – Life Processes

Q1. How do plants exchange gases?

Ans : Plants exchange gases through stomata. Large intercellular spaces ensure that each cell is in contact with air. Carbon dioxide and oxygen are exchanged here.

Q2. How are fats digested in our bodies? Where does this process take place?

Ans : Fats are first emulsified with the help of bile salts followed by their breakdown in fatty acids and glycerol due to the action of lipase. All these events take place in first part of small intestine-duodenum. Saprophytic

Q3Write one function each of the following components of the transport system in human beings blood vessels blood platelets Lymph Heart   

Ans : a. Blood vessels: transport of blood.

b. Blood platelets: clotting of blood preventing its loss/leakage.

c. Lymph: carries digested fats/protects from infection/exchange of materials between tissues and blood/drains excessive fluid back to blood.

d. Heart: pumps blood to all parts.

Q4 What is the role of saliva in digestion of food?

Ans : Saliva lubricates and softens the food so that it can be easily chewed and swallowed. It contains enzyme amylase which breaks down starch to maltose..

Q5. Why rate of breathing in aquatic animals has to be faster than that in terrestrial animals?

 Ans : Amount of O2 dissolved in water is less than O2 present in air therefore rate of breathing in aquatic animals has to be faster than that in terrestrial animals. Terrestrial organism need not spend so much energy to obtain oxygen.

Q6. What are the raw materials for photosynthesis. How are they obtained by a plant?

Ans : CO2 and water are needed for the photosynthesis. CO2 enters the leaf through stoma present on its surface. These pores open in day time in most of plants though in desert plants they open at night to reduce the loss of water. Water is absorbed by roots from the soil along with other materials like nitrogen, phosphorus, iron and magnesium.

Q7. How do autotrophs obtain CO2 and N2 to make their food?

Ans :  CO2 from environment/atmosphere through diffusion/ stomata. Nitrogen from soil/environment in inorganic (nitrates) or organic form.

Q8. What is the difference between Xylem and Phloem?

Ans : There are two conducting tissues in transport system of plants, first is xylem and second is phloem.

Q9.What is respiration? What is its importance for an organism.

Ans :The breakdown of food in cells to release energy. All kind of food is broken down through oxidation reduction reaction and its chemical energy is converted into a universal source of chemical energy – ATP, Adenosine Tri Phosphate.

Q10. What is residual volume in our lungs? What is its importance? 

Ans : Residual volume is the amount of air which is always left inside the lungs in spite of forceful exhalation. It helps in continuous gas exchange during exhalation or inhalation.

Q11.  Show direction of flow of lymph with the help of flow diagram.

Ans : Lymph ” tissue ” sinus ” lymph vessel ” vein ” heart.

Q12. Name the respiratory pigment in human beings? What is its role? 

Ans : Respiratory pigment, haemoglobin is present in red blood cells. Haemoglobin has affinity for O2 thus helping in its transport.

Q13. What are enzyme? Do they play some role in our digestive system too?

Ans :  They are chemically proteinaceous biocatalyst, which increase or decrease the rate of a biochemical reaction. The enzyme present in our digestive system help to breakdown of complex molecules of food into simpler ones.

Q14. What is the role of large intestine?

Ans : Water re-absorption occurs through villi, undigested food is stored in rectum and thrown out through anus. Exit is regulated by anal sphincter.

Q15. Discuss how the roles of vena cava and pulmonary veins different from each other?

 Ans : Pulmonary vein carries oxygenated blood from lungs to left auricle of heart in humans. Vena Cava collects deoxygenated blood from all parts of the body and transport it to right auricle of the heart in human.

Q16. Why is it advisable to breathe through nose?

Ans : There are fine hair and mucus gland in the inner lining of nose which filter the incoming air of germs and dust. Moreover the air attains the optimum temperature before reaching the lungs.

Q17 Define transpiration. How does transpiration help in upward movement of water from roots to leaves? .

Ans : Transpiration is the process of removal of water vapours from the aerial parts of a plant, mainly through stomata in the leaves. Evaporation of water molecules from the cells of a leaf creates a suction force which pulls water from the xylem cells. This transpiration helps in upward movement of water from roots to leaves.

Q18.  Describe the structure of the human heart briefly.

Ans : Human heart is four chambered. The two upper chambers are called atria and they receive blood from large veins while the two lower chambers are called ventricles. Between left atrium and left ventricle as well as between right atrium and right ventricle are valve which allow blood to flow only from atrium to ventricle.

Q19.List two ways in which plants can get rid of the wastes.

Ans : They can throw gases and excess water through stomata through diffusion. They can store wastes like gums and resins in old xylem tissue (wood).

Q20. What is the role of acid and mucus in stomach?

 Ans : It kills germs in food and provides acidic medium for the action of pepsin enzyme to digest the proteins in stomach. Mucus protects the wall of stomach from the action of acid and pepsin.

Q21. Which digestive secretion does not contain any enzyme but is important? Discuss.

Ans : Bile juice from liver. It contains bile salts which are necessary for emulsification of fats. It means breaking down large fat drops to very fine droplets so that lipase can act upon them easily.