Class 9 Chapter 5/NCERT Problem Question Bank/Solved Exemplar Question/ Study Material
Class 9 Chapter 5/NCERT Problem Question Bank/Solved Exemplar Question/ Study Material
Here we are going to cover NCERT Chapter 5, i.e., The Structure and Fundamental Unit of Life: Cell’s NCERT solved problem question bank, Solved exemplar questions, and also be providing study material of this chapter. We will also provide extra help questions and many helpful notes that can help students for their better success.
Questions Based o NCERT Question Bank (Exemplar Problem in Science)
Q.1 Why are lysosomes known as suicide bags of a cell?
Ans.1) Lysosomes contain digestive enzymes for almost all types of organic materials. If their covering membrane breaks as it happens to the injury of the cell, the digestive enzymes spread over the cell contents and digest the same. As lysosomes are organelles that on bursting can kill cells possessing them, they are called suicide bags of the cell.
Q.2. Do you agree that A cell is a building unit of an organism?
Ans.2) Yes, the cell is a building unit of every living organism as every living being is made up of one or more cells. For example, in unicellular or cellular organisms, the single cell performs all the functions of life. In multicellular or organisms, all the cells have a similar basic structure and perform a basic life activity. However, they become specialized to form components of different structures that perform different functions. Cells are first organized into tissues, each with a specific function, e.g., heart, kidney, lung, stomach, eyes. Organs are grouped into organ systems, each with a major function e.g., circulatory system, excretory system, respiratory system, digestive system, skeletal system. A living organism has a number of organ systems. Thus, in all such organizational complexity, the cell remains the basic building unit of the organism.
Q.3. Why does the skin of your fingers shrink when you wash clothes for a long time?
Ans.3) Clothes are washed with soap or detergent solution. This solution is hypertonic as compared to the osmotic concentration of our skin cells. The washing solution, therefore, results in exosmosis in the skin cells that come in contact with it for some time. Due to this reason, the skin over the fingers shrinks while washing clothes for a long time.
Q.4 Why is endocytosis found in animals only?
Ans.4) Endocytosis is swallowing up of food and other substances (bacteria, viruses) from the external medium by the plasma membrane, This is possible only when the plasma membrane is in direct contact with the external medium. It occurs only in animal cells. In-plant cells, a cell wall is present over the plasma membrane. Therefore, their plasma membrane cannot perform endocytosis.
Q.5. A person takes the concentrated solution of salt. After some time he starts vomiting. What is the phenomenon responsible for such a situation? Explain.
Ans.5) Concentrated salt solution is a hypertonic solution so causes irritation and excessive dehydration in the wall of the alimentary canal due to exosmosis. There is uncomfortable stretching which causes reverse movements and hence vomiting.
Q.6. Name any cell organelle which is non-membranous.
Ans.6) Ribosome.
Q.7 We eat food composed of all the nutrients such as carbohydrates, proteins, fats, vitamins, minerals, and water. After digestion, they are absorbed in the form of glucose, amino acids, fatty acids, glycerol, etc. What mechanisms are involved in the absorption of digested food and water?
Ans.7) Digested food is taken in the intestinal cells by the following process:
- Glucose, amino acids, and some ions- Active transport.
- Fatty acids, glycerol-Diffusion (passive transport).
- Water- osmosis.
Q.8 If you are provided with some vegetables to cook, you generally add salt into food during the cooking process. After adding salt, vegetables release water. What mechanism is responsible for this?
Ans.8) On adding salt, vegetables release water due to exosmosis. Exosmosis occurs whenever the external medium is hypertonic as compared to the osmotic contraction inside the living cell.
Q.9 If cells of onion peel and RBC are separately kept in hypertonic solution what among the following will take place? Explain the reason for your answer. (a) Both the cells will swell. (b) RBC will burst easily while cells of onion peel will resist the bursting to some extent. (c) ‘A’ and ‘B’ both are correct (d) RBC and Onion cells will behave similarly.
Ans.9) (b) RBC will burst as there is no mechanism to resist the entry of water into them. Onion peel cells do not burst. Endosmosis is caused by some internal swelling in such onion peel cells but the cell wall puts a mechanical barrier to promote entry of water. Therefore, these cells do not burst.
Q.10 Bacteria do not have chloroplast but some bacteria are photoautotrophic in nature and perform photosynthesis. Which part of the bacteria cell performs this?
Ans.10) photoautotrophic bacteria possess photosynthetic pigment inside small vesicles which may be attached to the plasma membrane.
Q.11 Match the following
A |
B |
| (a) Smooth E.R
(b) Lysosome (c) Nucleoid (d) Food vacuoles (e) Chromatin material and nucleolus
|
(i) Amoeba
(ii) Nucleus (iii) Bacteria (iv) Detoxification (v) Suicidal bag
|
Ans.11) a-iv, b-v, c-iii, d-i, e-ii.
Q.12 Write names of different plants parts in which chloroplast, chromoplast, and leucoplast are present.
- Chromoplast: Flower (Petals) and fruits.
- Chloroplast: Green leaves and green pars.
- Leucoplast: Root and underground stem.
Q.13 Name the organelles which show analogy written asunder
- transporting channels of the cell…………
- Power hose f the cell……….
- Packaging and dispatching unit of the cell……….
- Digestive bag of the cell……..
- Storage sac of cell…….
- Kitchen of the cell……..
- Control room of the cell……..
Ans.13) (1.) E.R
(2.) Mitochondria
(3.) Golgi apparatus
(4.) Lysosome
(5.) Vacuole
(6.) Chroloplast
(7.) Nucleus
Q.14 How is the onion cell is different from the onion peel cell?
Ans.14)
Bacteria Cell |
Onion peel cell |
| 1. Size is generally small.
2. Nucleus is absent. 3. It contains a single chromosome. 4. Nucleolus is absent. 5. Membrane-bound cell organelles are absent. 6. Cell division takes place by fission or building. |
1. Size is generally large.
2. Nucleus is generally present. 3. It contains more than one chromosome. 4. Nucleolus is present. 5. Membrane-bound cell organelles are present. 6. Cell division occurs by mitotic or meiotic cell division. |
Q.15 how substances such as Co2 and water move in and out of the cell?
Ans.15) Co2 and water move in and out of the cell by diffusion and osmosis respectively.
For more helpful study material and notes click on the links below:
NCERT Solutions for the structural and Fundamental Unit of Life-Cell Class 9th
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