NCERT Solutions for Class 8 Science Chapter 8 Cell Structure and Function

Q1. Indicate whether the following statements are True (T) or False (F)

(a) Unicellular organisms have one-celled body. (T/F)

Answer:

(True) uni refers to only one.

Q1. Indicate whether the following statements are True (T) or False (F).

(b) The basic living unit of an organism is an organ. (T/F)

Answer:

( False ) Basic unit of life is a cell.

Q1. Indicate whether the following statements are True (T) or False (F).

(c) Amoeba has irregular shape. (T/F)

Answer:

( True ) Amoeba has irregular shape

CBSE NCERT solutions for class 8 science chapter 8 cell structure and function

Q2. Make a sketch of the human nerve cell. What function do nerve cells perform?

Answer:

Here is the sketch of the human nerve cell:

Function-

The nerve cell receives and transfers messages, thereby helping to control and coordinate the working of
different parts of the body.

Q3. Write short notes on the following.

(a) Cytoplasm

Answer:

Cytoplasm -The jelly-like substance between the nucleus and the cell membrane is called cytoplasm. nucleus. Various other components, organelles, of cells are present in the cytoplasm. These are mitochondria, Golgi bodies, ribosomes, etc.

Q3. Write short notes on the following.

(b) Nucleus of a cell

Answer:

Nucleus of the cell-

It is an important component of the living cell. It is generally spherical and located in the centre of the cell. the nucleus contains thread-like structures called chromosomes. These carry genes and help in inheritance or transfer of characters from the parents to the offspring.

Q4. Which part of the cell contains organelles?

Answer:

The cytoplasm is the part of the cell that contains organelles like are mitochondria, Golgi bodies, ribosomes, etc.

NCERT solutions for class 8 science chapter 8 cell structure and function:

Q5. Make sketches of animal and plant cells. State three differences between them.

Answer:

Differences between them-

Plant cell-

1. The cell wall is present
2. the large size of vacuoles
3. Plastides are present

Animal Cell-

1. The cell wall is absent
2. vacuole size is small as compared to plant cell
3. No plastids, except for protozoan euglena

Q6. State the difference between eukaryotes and prokaryotes.

Answer:

Eukaryotes -

• mostly are multicellular
• the nucleus is well defined and surrounded by the nuclear membrane.
• nucleolus is present
• All organisms other than bacteria and blue-green algae are called eukaryotes.

Prokaryotes -

• These are mostly unicellular
• The nucleus of the bacterial cell is not well organised
• There is no nuclear membrane.
• bacteria and blue-green algae are prokaryotes

Q7. Where are chromosomes found in a cell? State their function.

Answer:

Chromosomes (thread like structure) found inside the nucleus. It plays an important role.

These carry genes and help in inheritance or transfer of characters from the parents to the offspring

CBSE NCERT solutions for class 8 science chapter 8 cell structure and function:

Q8. ‘Cells are the basic structural units of living organisms’. Explain.

Answer:

The cell is the smallest unit of living organisms and is capable of all life functions. These are the building blocks of life. that's why cells are referred to as the 'basic structure and functional unit of life'.

Q9. Explain why chloroplasts are found only in plant cells?

Answer:

In a plant cell, green coloured plastids are called chloroplasts.

They provide green colour to the leaves.chlorophyll in the chloroplasts of leaves, is essential for photosynthesis. Since photosynthesis can perform by only plants so chloroplast is present in plants.

Q10. 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.

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.

Answer:

Across

1. CHLOROPHYLL

3. ORGANELLE

6. PROTOPLASM

8. GENES

Down

1.CHLOROPLASTS

2.ORGAN

4. MEMBRANE

5. VACUOLE