NCERT Solutions for Class 8 Science Chapter 8 Cell Structure and Functions
Here you will find NCERT Solutions for Class 8 Science Chapter 8 Cell Structure and Functions which will make entire memorizing process effortless and entertaining. These are very much essential in steering students towards their goal. Given Class 8 Science NCERT Solutions are available in understandable language and encourage students to learn new topics. It will help in developing a wider body of knowledge when you’re brainstorming a solution.
These NCERT Solutions for Class 8 Science help you in improving the marks in the examinations and have edge over your classmates. Chapter 8 Cell Structure and Functions Class 8 Science NCERT Questions and Answers will serve as beneficial tool that can be used to recall various questions any time. It is very challenging to score good marks in tests that is why we have prepared NCERT Solutions.
NCERT Solutions for Class 8 Science Chapter 8 Cell Structure and Functions
Through these Class 8 Science NCERT Solutions, students should not waste time and adopt a strategy that helps them operate and learn at maximum efficiency. It will make you aware of the all the topics and ensure consistency in the preparation level. You will develop the ability to identify what improvements and changes need to be made. These Science NCERT Solutions are curated by the experts in a comprehensive which can be helpful in clearing your doubts instantly.
| Study Material for Class 8 Science Chapter 8 Cell Structure and Functions |
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Page No: 100
Exercise
1. Indicate whether the following statements are True (T) or False (F).
(a) Unicellular organisms have one-celled body. (T / F)
► True
(b) Muscle cells are branched. (T / F)
► False
(c) The basic living unit of an organism is an organ. (T / F)
► False
(d) Amoeba has irregular shape. (T / F)
► True
2. Make a sketch of the human nerve cell. What function do nerve cells perform?
Answer
3. Write short notes on the following.
(a) Cytoplasm: It is a fluid that fills the cell and occurs between the plasma membrane and the nucleus. Cell organelles such as mitochondria, ribosomes, Golgi bodies, etc. are suspended in the cytoplasm. The cytoplasm helps in the exchange of materials between cell organelles.
(a) Cytoplasm: It is a fluid that fills the cell and occurs between the plasma membrane and the nucleus. Cell organelles such as mitochondria, ribosomes, Golgi bodies, etc. are suspended in the cytoplasm. The cytoplasm helps in the exchange of materials between cell organelles.
(b) Nucleus of a cell: Nucleus is the master of the cell. It commands all the functioning of the cell. It is generally located in the center of the cell and is spherical in shape. A membrane called nuclear membrane separates it from cytoplasm. It contains the genetic material DNA and RNA in it. This porous membrane allows the transfer of material in the nucleus and cytoplasm. Nucleus contains a dense body called Nucleolus which actually contains Chromosomes, the genetic material.
4. Which part of the cell contains organelles?
Answer
Cytoplasm is the part of the cell that contains various organelles such as mitochondria, ribosomes, Golgi bodies, etc.
5. Make sketches of animal and plant cells. State three differences between them.
Answer
Animal cell
|
Plant cell
|
| They are generally small in size. | They are usually larger than animal cells. |
| Cell wall is absent. | Cell wall is present. |
| Vacuoles are small in size. | Vacuoles are larger in size. |
| No other animal cell possesses plastids except for the protozoan Euglena. | Plastids are present. |
6. State the difference between eukaryotes and prokaryotes.
Answer
7. Where are chromosomes found in a cell? State their function.
Answer
Chromosomes are found in the nucleus of a cell. Their function is to carry characteristic features of parent cells to the daughter cell means, from parent to offspring.
8. 'Cells are the basic structural units of living organisms'. Explain.
Answer
In Biology, the basic unit of which all living things are composed is known as ‘cell’. The ‘cell’ is the smallest structural unit of living matter that is capable of functioning independently. A single cell can be a complete organism in itself, as in bacteria and protozoans. A unicellular organism also captures and digests food, respires, excretes, grows, and reproduces. Similar functions in multi-cellular organisms are carried out by groups of specialized cells which are organized into tissues and organs such as, the higher plants and animals. Hence, ‘cell’ is known as the basic structural and functional unit of life.
9. Explain why chloroplasts are found only in plant cells?
Answer
Chloroplasts are found only in plant cells because they are required for photosynthesis.
10. Complete the crossword with the help of clues given below.
Answer
Prokaryotes
|
Eukaryotes
|
| Most prokaryotes are unicellular. | Most eukaryotes are multicellular. |
| The nucleus is poorly defined due to the absence of a nuclear membrane. | The nucleus is well defined and is surrounded by a nuclear membrane. |
| Nucleolus is absent | Nucleolus is present. |
| Cell organelles such as plastids, mitochondria, golgi bodies, etc. are absent. | Cell organelles such as plastids, mitochondria, golgi bodies, etc. are present. |
| Bacteria and blue-green algae are prokaryotic cells. | Fungi, plant, and animal cells are eukaryotic cells. |
7. Where are chromosomes found in a cell? State their function.
Answer
Chromosomes are found in the nucleus of a cell. Their function is to carry characteristic features of parent cells to the daughter cell means, from parent to offspring.
8. 'Cells are the basic structural units of living organisms'. Explain.
Answer
In Biology, the basic unit of which all living things are composed is known as ‘cell’. The ‘cell’ is the smallest structural unit of living matter that is capable of functioning independently. A single cell can be a complete organism in itself, as in bacteria and protozoans. A unicellular organism also captures and digests food, respires, excretes, grows, and reproduces. Similar functions in multi-cellular organisms are carried out by groups of specialized cells which are organized into tissues and organs such as, the higher plants and animals. Hence, ‘cell’ is known as the basic structural and functional unit of life.
9. Explain why chloroplasts are found only in plant cells?
Answer
Chloroplasts are found only in plant cells because they are required for photosynthesis.
10. Complete the crossword with the help of clues given below.
Across
1. This is necessary for photosynthesis.
3. Term for component present in the cytoplasm.
1. This is necessary for photosynthesis.
3. Term for component present in the cytoplasm.
6. The living substance in the cell.
8. Units of inheritance present on the chromosomes.
Down
1. Green plastids.
2. Formed by collection of tissues.
4. It separates the contents of the cell from the surrounding medium.
5. Empty structure in the cytoplasm.
7. A group of cells.
8. Units of inheritance present on the chromosomes.
Down
1. Green plastids.
2. Formed by collection of tissues.
4. It separates the contents of the cell from the surrounding medium.
5. Empty structure in the cytoplasm.
7. A group of cells.
Answer
1. CHLOROPHYLL
3. ORGANELLE
6. PROTOPLASM
8. GENES
Down
1. CHLOROPLASTS
2. ORGAN
4. MEMBRANE
5. VACUOLE
7. TISSUE
6. PROTOPLASM
8. GENES
Down
1. CHLOROPLASTS
2. ORGAN
4. MEMBRANE
5. VACUOLE
7. TISSUE
Go Back To NCERT Solutions for Class 8 Science
Chapter 8 Cell Structure and Functions Class 8 Science NCERT Solutions
Chapter 8 Class 8 Science NCERT Solutions will be useful in gaining good marks in the examinations. Through these NCERT Solutions, a student can boost their preparation and assessment of understood concepts. It will make you well versed in variety of topics and you will be able to instantly recollect your ideas and shape your answers.
Class 8 Science Chapter 8 Cell Structure and Functions NCERT Questions and Answers - Topics
• Discovery of the Cell
• The Cell
• Organisms show Variety in Cell Number, Shape and Size
→ Number of Cells
→ Shape of Cells
→ Size of Cells
• Cell Structure and Function
• Parts of the Cell
→ Cell Membrane
→ Cytoplasm
→ Nucleus
• Comparison of Plant and Animal Cells
Class 8 Science Chapter 8 Cell Structure and Functions NCERT Questions and Answers - Notes
• Cell is the basic structural unit of an organ.
• Robert Hooke in 1665, observed a thin slice of cork under a magnifying device. He observed partitioned compartments which he termed as cells.
• Cells in the living organisms are complex living structures unlike non-living bricks.
• Human body has trillions of cells which vary in shapes and sizes. Different groups of cells perform a variety of functions.
• Organisms made of more than one cell are called multicellular (multi : many; cellular : cell) organisms.
• The single-celled organisms are called unicellular (uni : one; cellular : cell).
• The shape of cells are irregular. Amoeba has no definite shape, unlike other organisms. It keeps on changing its shape. The projections of varying lengths protruding out of its body which are called pseudopodia.
• The size of cells in living organisms may be as small as a millionth of a metre (micrometre or micron) or may be as large as a few centimetres.
• The smallest cell is 0.1 to 0.5 micrometre in bacteria. The largest cell measuring 170 mm ×130 mm, is the egg of an ostrich.
• A tissue is a group of similar cells performing a specific function.
• The basic components of a cell are cell membrane, cytoplasm and nucleus
→ The cytoplasm and nucleus are enclosed within the cell membrane, also called the plasma membrane. It is porous and allows the movement of substances or materials both inward and outward.
→ The central dense round body in the centre of the cell is called the nucleus. A smaller spherical body in the nucleus. It is called the nucleolus. Nucleus contains thread-like structures called chromosomes. These carry genes and help in inheritance or transfer of characters from the parents to the offspring.
→ The jelly-like substance between the nucleus and the cell membrane is called cytoplasm.
→ An outer thick layer in cells of plants called cell wall. This additional layer surrounding the cell membrane is required by plants for protection.
→ The entire content of a living cell is known as protoplasm. It includes the cytoplasm and the nucleus. Protoplasm is called the living substance of the cell.
• The cells having nuclear material without nuclear membrane are termed prokaryotic cells. Examples are bacteria and blue green algae.
• The cells, like onion cells and cheek cells having well-organised nucleus with a nuclear membrane are designated as eukaryotic cells. Examples are all organisms other than bacteria and blue green algae.
Chapter 8 Cell Structure and Functions Class 8 Science Questions and Answers - MCQ Questions with answers
1. Single celled organisms are called
a) Unicellular
b) Multicellular
c) Both of these
d) None of the above
► a) Unicellular
2. Tissue is a
a) Group of organs
b) Group of cells
c) Group of tissues
d) Group of organisms
► b) Group of cells
3. Living substance of a cell is collectively known as:
a) blood
b) protoplasm
c) nucleoplasm
d) cytoplasm
► b) protoplasm
4. Which of the following gives the cell its shape, maintains its size, protects the internal structures inside and is selectively permeable?
a) Cell wall
b) Nuclear membrane
c) Cell membrane
d) Tonoplast
► c) Cell membrane
5. Which of the following is a saclike structure that store food, wastes and water?
a) Lysosomes
b) Centrosomes
c) Chromosomes
d) Vacuoles
► d) Vacuoles
6. Which of the following group is prokaryotes ?
a) brown algae
b) protozoa
c) both blue-green algae and brown algae
d) blue-green algae
► d) blue-green algae
7. A single cell that can change its shape is:
a) Paramecium
b) HIVs
c) WBCs
d) None of the above
► c) WBCs
8. Which of the following is the jellylike substance inside the plasma membrane in which all the cell organelles are found floating?
a) Tonoplasm
b) Cytoplasm
c) Karyoplasm
d) Cell sap
► b) Cytoplasm
9. Which of the following functions is performed by the carbohydrates of the plasma membrane?
a) Passive transport
b) Active transport
c) Cell adhesion
d) Cellular recognition
► d) Cellular recognition
10. The plastid responsible for fruit colour is:
a) chromoplast
b) amyloplast
c) chloroplast
d) leucoplast
► a) chromoplast
NCERT Textbook will provide you with a lot of interesting topics thus these Class 8 NCERT Solutions will be useful in understanding in depth concepts well. Students can cross check their answers and also whether they learned it properly or not. These NCERT Solutions for Class 8 Science for Chapter 8 are curated by the experts in a comprehensive which can be helpful in clearing your doubts instantly.