RBSE Class 9 Science Chapter 8 - Major Activities of Living Organism Solutions

RBSE Class 9 Science Chapter 8 – Major Activities of Living Organism Solutions is the perfect resource for students to get a grip of all the concepts of the chapter thoroughly, thus helping them get high scores in the exams. Students use these solutions in order to revise the complete chapter thoroughly. They can practice these solutions and master the subject proficiently. Solving these questions from the RBSE Class 9 Solutions for Chapter 8 Science helps students to cover all the main topics in the chapter. Students are advised to solve these chapter-wise important topics and questions from the RBSE Class 9 Science to prepare most efficiently for the exams. In the meantime, students are encouraged to implement a comprehensive strategic learning process in order to improve their performance. Here, we have listed the important questions from, Chapter 8, Major Activities of Living Organism of RBSE Class 9 Science Textbook. Practising these questions will help the students to master the subject and score high marks. Students will also be able to learn the basics of the subject before moving to higher classes, and it will help them to do well for the academic year.

Rajasthan Board Class 9 Science Chapter 8- BYJU’S Important Questions & Answers

RBSE Class 9 Science Chapter 8 Objective Questions-Important Questions and Solutions

1. In plants water condition takes place through :

(a) Phloem

(b) Xylem

(c) Sieve tubes

(d) Epidermis

Answer: (b) Xylem

2. The water available in soil for plant use is :

(a) Hygroscopic water

(b) Gravitational water

(c) Water obtained from guttation

(d) Capillary water

Answer: (d) Capillary water

3. Exchange through stomata, takes place of :

(a) Water vapour and gases

(b) Oxygen and Hydrogen

(c) Oxygen and Carbohydrates

(d) Nitrogen and Water vapour

Answer: (a) Water vapour and gases

4. Food material is conducted through :

(a) Xylem

(b) Phloem

(c) Stomata

(d) Epidermis

Answer: (b) Phloem

5. Respiratory pigment is :

(a) Red Blood Corpuscles

(b) White Blood Corpuscles

(c) Haemoglobin

(d) None of the above

Answer: (c) Haemoglobin

6. The systolic pressure of a normal body is :

(a) 120 nm

(b) 90 nm

(c) 140 nm

(d) 180 nm

Answer: (a) 120nm

7. Which of the following is not a function of the stomach :

(a) Storage of food

(b) Absorption

(c) Digestion

(d) Complete digestion of fats

Answer: (d) Complete digestion of fats

8. The main example of fragmentation is :

(a) Spirogyra

(b) Bryophyllum

(c) Yeast

(d) Amoeba

Answer: (a) Spirogyra

9. The main method of reproduction in Rhizopus is :

(a) Binary fission

(b) Budding

(c) Sporogenesis

(d) Multiple fission

Answer: (c) Sporogenesis

10. Ovules are located in :

(a) Ovary

(b) Style

(c) Anther

(d) Embryosac

Answer: (a) Ovary

11. In plants, the metabolic process are mainly based on :

(a) Protein

(b) Fats

(c) Carbohydrates

(d) Vitamins

Answer: (c) Carbohydrates

12. Hydathodes are present on :

(a) Roots

(b) Stem

(c) Leaves

(d) Flowers

Answer: (c) Leaves

13. Guttation can be observed when :

(a) Respiration is more

(b) More absorption and less transpiration

(c) Photosynthesis is more

(d) Diffusion is more

Answer: (b) More absorption and less transpiration

14. Ureotelic excretion occurs in :

(a) Amoeba and Frog

(b) Birds and fishes

(c) Fishes and snakes

(d) Man and frog

Answer: (c) Fishes and snakes

RBSE Class 9 Science Chapter 8 Very Short Answer Type Questions-Important Questions and Solutions

15. Excretion in aquatic plants occurs by which method?

Answer: Excretion in aquatic plants occurs through diffusion.

16. What is the function of the guard cells?

Answer: Cells surrounding the Stomata are known as guard cells. These guard cells can help to regulate the rate of transpiration by opening and closing the stomatal pores. They become turgid and open the stomatal pore on receiving water from the neighbouring cells. Air, carrying carbon-di-oixde, enters the leaf through these open pores. The stomatal cells close off, when these guard cells lose water and become flaccid.

17. What is uricotelic excretion?

Answer: Removal of nitrogenous wastes as uric acid in the form of pellets or paste by uricotelic animals is known as uricotelic excretion. In this process, water loss is minimal and is considered least toxic. Also, since the uric acid is not that easily soluble in water, excrements form pasty white suspensions.

18. Name the two main parts of a plant.

Answer: Root and leaves are two key parts of a plant.

19. Which conducting tissue is responsible for conduction of water from the roots to the leaves?

Answer: Xylem is a complex tissue that has vessels and tracheid for the conduction of water.

20. What is the function of Phloem?

Answer: The phloem is used to transfer the food that has been synthesized during photosynthesis, in dissolved state, to various parts of the plant body. Phloem use particular sieve tubes for this purpose.

21. Define plasmolysis.

Answer: Plasmolysis takes place in plant cells. It is the process of shrinking of the protoplast because of exosmosis

22. What is respiration?

Answer: A biochemical process where the living cells of the organism produce energy by breathing in oxygen and liberating carbon dioxide, resulting from the oxidation of complex organic substances. Cellular respiration is the process of oxidation of nutritive substances.

23. What is Binary fission?

Answer: A complex process of mitotic division or asexual reproduction, in which an organism divides into two similar types. In unicellular organisms, it is seen that similar organisms originate from cell division or fragmentation.

24. What is a Thalamus?

Answer: A flower is composed of two accessory organs, calyx and corolla and of reproductive organs, androecium and gynoecium, which are arranged on a stalk called receptacle (thalamus).

25. Give examples of air-layering technique.

Answer: Pomegranate and Litchi are examples of air-layering technique.

26. What is the need of reproduction in an organism?

Answer: Reproduction is a process that ensures that life is continued on earth and that a particular species is surviving. Various trees and plants, like neem, babool etc, deliver numerous saplings during the rainy season. Also, babies of various birds like sparrow, pigeon, hen etc, come out of the eggs. All these gradually develop into adults and even produce off-spring of their own, once they mature. Thus, a continuity of the various species is maintained in this universe.

RBSE Class 9 Science Chapter 8 Short Answer Type Questions-Important Questions and Solutions

27. Write the difference between the tap root and the adventitious root.

Answer: To learn more about the root system, detailed explanation on the taproot system and adventitious root system check out the difference between tap root and fibrous root.

28. Differentiate between the xylem and phloem tissue.

Answer: Xylem tissues are tubular-shaped structures, with the absence of cross walls, resembling the shape of a star, while Phloem tissues are elongated, tubular-shaped structures that include thin sieve tubes with walls. Both are different vascular tissues involved in the transportation process. Xylem fibres are smaller and the tissue occupies the centre of the vascular bundle. At the same time, Phloem fibres are larger and the tissue is located on the outer side of the vascular bundle. Xylem tissues are uni-directional moving only upwards, while Phloem tissues are bi-directiona, moving both up and down. For detailed description and differences, check out differences between Xylem and Phloem.

29. Define the following terms : Diffusion, Osmosis, Plasmolysis, endosmosis

Answers: Diffusion– The movement of molecules from a region of higher concentration to a region of lower concentration. Further details can be obtained from the page diffusion in plants.

Osmosis is the process of moving solvent particles across a semipermeable membrane from a dilute solution into a concentrated solution to equalize concentration. Learn more from the difference between diffusion and osmosis.

Plasmolysis– If a cell is placed in a solution having concentration more than that of the cell sap, the water from the cell sap will move out into the external solution and the cell will shrink. The cell wall will shrink only to a particular limit; then after the protoplast will separate from the cell wall and will ultimately appear as a shrunken round or oval mass on one side of the cell. This process of shrinking of the protoplast because of exosmosis is known as plasmolysis. Exosmosis is the movement of water out of the cell, by osmosis.

Endosmosis-When a cell is placed in a hypotonic solution, the water moves inside a cell and swells. For the complete answer, check out the difference between endosmosis and exosmosis.

30. According to which theory does the water reach the leaves from the roots? Explain it.

Answer: In the pores in between the soil particles, air and water are present. The water

present is known as the capillary water. The roots of the plants absorb this water primarily by the root hair region of the roots. Mineral salts remain dissolved in the capillary- water of the soil. Hence, it is a dilute solution and the concentration of cell sap is more than the concentration of this solution. Hence, the water from the soil enters the root hair cells by osmosis. The cell sap thus gets diluted as compared to the sap in the nearby cells and water moves to the next cell by osmosis. In this manner a pressure gradient is created from the xylem vessels to the cortical cells and root hairs. The water with the dissolved salts move up regularly from the root hairs to the root xylem because of this gradient. If the osmotic pressure of root hairs is less than the osmotic pressure of the soil solution, according to the principle of osmosis, exosmosis should occur. Under such circumstances too, the root hair can absorb water. Energy is required for such absorption, known as active absorption, provided by the ATP molecules that are present in the cell.

31. Describe the functions of stomata.

Answer: Minute openings or pores generally found in the lower epidermis of leaves are called stomata. Stomata plays a crucial role by allowing the movement of gases such as oxygen, carbon dioxide and water vapour to diffuse between the interior and outer surface of the plant tissues. The main functions of stomata are:

  • Helps in the exchange of gases by opening and closing the pores in the leaves.
  • It helps to expel the excess water out from the leaves in the form of water vapour.
  • According to the weather conditions, it closes or opens its pores to maintain the moisture balance.
  • Allows the uptake of carbon dioxide and to give out oxygen during the process of photosynthesis.
  • Stomata remain open during the day and closed at night. This closure prevents water from escaping through open pores.

32. How many types of circulatory systems are present in animals? Explain giving examples.

Answer: There are two types of circulatory systems present in the animals- Open circulatory system and closed circulatory system. Open circulatory system is primarily found in invertebrates. Here, the blood flows freely through cavities and there are no vessels to conduct the blood. Closed circulatory systems are found in vertebrates and a few invertebrates like earthworms. This system has the presence of vessels that conduct blood throughout the body.

Details are found in the open circulatory system and closed circulatory system page.

33. What are the anabolic and catabolic reactions?

Answer: Metabolism is a set of chemical reactions carried out for maintaining the living state of the cells in an organism. These are divided into two categories:

  • Catabolism – the process of breaking molecules to obtain energy.
  • Anabolism – the process of synthesizing all compounds required by the cells.

Anabolism is a biochemical process in metabolism, in which the simple molecules combine to generate complex molecules. This process is endergonic and not spontaneous. It requires energy to progress the anabolic reaction. The complex molecules obtained are further used to store energy in the form of ATP (Adenosine Tri Phosphate). Alternatively, Catabolism is the breakdown of complex molecules. It is the degeneration of complex substances to their constituent parts (glucose, amino acids and fatty acids) which form substrates for metabolic pathways. Hence, respiration is a catabolic process that breaks large molecules into smaller ones, releasing energy to fuel cellular activities. The major differences between Catabolism and Anabolism are the way the molecules are utilized in the body. Cells use an anabolic process to make polymers, repair, and grow tissues. Anabolism produces molecules the body needs for functionality and it uses up energy in the process. Catabolism, on the other hand, breaks down complex molecules and releases energy that is available for the body to use. Learn more about anabolic and catabolic reactions.

34. Why are special excretory organs not present in plants? Explain.

Answer: Process of eliminating the toxic and metabolic waste products from the body of a living organism is called excretion. Organisms like animals have an advanced and specialized system for excretion. However, plants lack a well-developed excretory system like that found in animals. Since, the excretion in plants is not so complex, they do not have special organs for excretion. Excretion of gaseous waste in plants and excess of water takes place through stomatal pores on leaves. Excretion in plants can be summarized via diffusion, transpiration and storing. Know more about excretion in plants by clicking on the link.

35. What is budding?

Answer: In some organisms, there are some cells that have the capacity to reproduce a bud on the animal body, such as an outgrowth that develops into an individual. The new organism that is formed separate from the parent organism, only when mature. This method is known as budding. Example : Hydra. In fungi, vegetative reproduction takes place by budding.

36. Explain reflex action with example.

Answer: Reflex actions are involuntary or sudden responses that are not controlled by our will power. They are controlled by the spinal cord. Like, when a thorn is pricked in the leg, reflex action occurs very quickly thus protecting the organism from the harmful sensations instantly. The spinal cord controls the reflex action so the brain gets enough opportunity for other important body functions. Detailed information about reflex action is found in the webpage linked.

RBSE Class 9 Science Chapter 8 Essay Type Questions-Important Questions and Solutions

37. What is guttation? Explain with the help of examples.

Answer: When you stand beneath a peepal tree, early in the morning, minute water droplets may fall on you. This is the water released by the leaves of this tree. Similar is the case with tomato, grass and so on, where water oozes out at the margins or the apex of leaves, in the form of droplets. The exudation of water droplets, from leaves, is known as guttation. These plants have special pores, known as the hydathodes, at the end of veins of the leaves for guttation. Each minute pore opens in a small cavity that is lined by thin walled, soft parenchymatous cells. Guttation is maximum in the state of more absorption and less transpiration. The water droplets contain some dissolved waste substances which deposit as a crust around the pores, on getting dry.

38. Explain the internal structure of a leaf?

Answer: To know how the leaves perform photosynthesis, it is necessary to get an idea about the internal structure of a leaf. The parts of a leaf include the upper epidermis, lower epidermis, mesophyll and vascular bundles. In a leaf, the external part with the cuticle layer of wax and skinny part is known as the epidermis. Epidermis protects the internal structure of the leaf. There are living parenchymatous cells located below the upper epidermis of a leaf. Upper epidermis is usually guarded by non-cellular substance, cutin etc., while there are minute pores in the lower epidermis, known as stomata, which are surrounded by two guard cells. Meanwhile, the parenchymatous cells contain a pigment called chlorophyll. Intercellular spaces are present in between these cells that are interconnected with each other to facilitate the exchange of gases, like oxygen and carbon-di-oxide and the transpiration i.e. excretion of the water vapour and conduction of gases to all the cells of the leaves. There is a network of veins in the leaves. The main tissues for conduction are the xylem and phloem that are located in these veins. Meanwhile, the central leaf, or mesophyll are soft-walled, unspecialized cells of the type known as parenchyma. Also, the Xylem and Phloem together form the vascular bundle and are responsible for the transport of water, mineral ions and food throughout the plant.

39. Explain Root Pressure with the help of an experiment.

Answer: Active water absorption causes the water from the soil to reach the xylem of the roots and the cells of the root become turgid, as a result. The water reaching the xylem rises, in the xylem, for some height. This positive pressure in the roots is the root pressure. It is an active pressure that propels water in the xylem of some of the herbaceous plants.

Find the experiment here that explains root pressure. Take a potted healthy plant and cut the stem 7-8 cm above the soil, transversely. Now, connect a glass tube to this cut end with the help of a rubber tube. Fill the glass tube with some water and then mark the water level on it. The experimental set up is made air tight with the help of wax. After some time the water level in the glass tube starts increasing as a result of the root pressure. Root pressure is not enough to take the water up to the leaves of 300 meter tall trees or trees taller than that. Water reaches the leaves of tall trees by the transpiration – cohesion tension theory.

40. Give an illustrated account of the respiratory system in humans.

Answer:

RBSE Class 9 Science Chapter 8 Question 40 Solution

41. Explain the method of grafting.

Answer: A plant that has a well developed root system is the stock and the plant stem with better quality characteristics that are established on the root system is called the scion. A healthy branch of the stock and a scion of similar diameter are cut and the scion is tied to the stock bringing the vascular region of both in contact with each other. In a few days, the tissues of the stock and the scion will then combine and develop into a single plant. Meanwhile, different stages of grafting are also given here. They include (a) prepared scion (b) rooted stock (c) Scion inserted in the stock and (d) Graft showing growth.

42. What is double fertilization? Elucidate.

Answer: Double fertilization is the process by which sexual reproduction takes place in a flower. The pollen grains reach the stigma of a flower via pollination and there the pollen grain germinates and forms the pollen tube that enters the stigma and reaches the ovary. In the ovary, it enters the ovule through the micropyle. The two male gametes thus reach the embryo-sac situated in the ovule and one of the male gamete fuses with the egg cell forming the zygote

that develops into an embryo. This is true fertilization. The other male gamete fuses with the two polar nuclei, in the embryo sac. This process is known as triple fusion. Thus, during fertilization in angiosperms, there are two separate fusions within the embryo sac – the fusion of the two gametes (egg and male gamete) and the fusion of the three nuclei (one male gamete and two polar nuclei). This is known as Double fertilization. After fertilization, the ovule develops into the seed and the ovary into a fruit.

43. Write a note on pollination.

Answer: Pollination is the transfer of pollen grains to the stigma of the flower of the same species, following which the female and male gametes fuse. Pollination occurs by insects, air, water or by spontaneous dehiscence. Meanwhile, if a pollen grains from the same flower or from another flower on the same plant pollinate to form a flower, then it is self-pollination. Also, if the pollen grains of a different flowering plant of the same species pollinate the stigma, then it is called cross pollination.

44. Describe the reproductive system of humans with the help of well labelled diagrams.

Answer: The process of fusion of sperm with egg (ovum) to produce zygote is called fertilization, which is an important stage of reproduction in human beings. The fertilized egg is called the zygote. Zygote starts to divide into many cells and develops into an embryo that moves into the uterus and gets attached to its walls. This process is referred to as implantation, and the implanted embryo eventually develops into a fetus. Learn more about reproduction in human beings and the reproductive system of the humans here.

RBSE Class 9 Science Chapter 8 Additional Important Questions and Solutions

45. What is Heterotrophs?

Answer: Heterotrophs are organisms that are not able to synthesise their own food and have to

depend on other living beings for their food.

46. What is Saprobic Nutrition?

Answer: Organisms that obtain their nourishment from the dead and decaying organisms are

known as saprophytes and their mode of nourishment is of saprobic type. Examples given include Microbes, fungi, some protozoa and so on.

47. Write an equation that represents the entire process of photosynthesis.

Answer:

RBSE Class 9 Science Chapter 8 Question 47 Solution

48. Explain the importance of digestion.

Answer: The food obtained by various animals, from the plants is in a non-diffusible state. Digestion helps to convert them into diffusible simple compounds. It is the transformation of food in simple products. Many types of nutritive elements and molecules present in the food stuff are used in the creation of new tissue and repair of the existing tissues. Since the animals cannot synthesize these nutritive elements, these substances that are synthesized by plants, are reduced by digestion and are then absorbed by the animals.

49. Where are male and female reproductive cells formed?

Answer: Male reproductive cells or the. sperms are produced in the testis, while the female reproductive cell, i.e. the egg, is formed in the ovary.

50. What is the circulatory system?

Answer: Circulation is the process of translocating the absorbed nutritive substances, water and waste products from one part of the body to another and the system related to it is the circulatory system.

Understanding the textbooks and revising the entire concepts is the best way for the students to score well. They can also depend on these RBSE Class 9 Science Solutions to self-analyse their performance and study for the exams. Also, other study materials that the students can find to prepare most competently for the exams are the RBSE textbooks and sample papers.

Stay tuned to learn more about RBSE Exam pattern and other information.

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