SEBA Class 9 Science Important Chapter 5 The Fundamental Unit of Life

SEBA Class 9 Science Important Chapter 5 The Fundamental Unit of Life Solutions English Medium As Per SEBA New Syllabus to each chapter is provided in the list so that you can easily browse through different chapters SEBA Class 9 General Science Additional Solutions and select need one. NCERT Important Solutions For Class 9 General Science Download PDF. Important Notes for Class 9 Science.

SEBA Class 9 Science Important Chapter 5 The Fundamental Unit of Life

Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. Assam SEBA Board Class 9 Science Additional Question Answer are part of All Subject Solutions. Here we have given CBSE Class 9 Science Important Notes for All Chapters, You can practice these here.

The Fundamental Unit of Life

Chapter: 5

IMPORTANT QUESTION ANSWER

Answer the Following Question:

1. Who discovered the cell?

Ans: Robert Hooke.

2. What is the basic unit of life?

Ans: Cell.

3. What is the jelly-like substance inside the cell called?

Ans: Cytoplasm.

4. What is the function of mitochondria?

Ans: It produces energy in the form of ATP.

5. What is the function of the Golgi apparatus?

Ans: Packaging and transport of materials.

6. What is the process by which water moves across a cell membrane?

Ans: Osmosis.

7. Explain the structure and function of the plasma membrane.

Ans: The plasma membrane is a thin, flexible layer made of proteins and lipids. It is selectively permeable and regulates the entry and exit of materials through diffusion or osmosis.

8. Why are lysosomes called ‘suicide bags’ of the cell?

Ans: Lysosomes contain digestive enzymes that can break down the cell’s own components if damaged, leading to self-destruction. Hence, they are called ‘suicide bags’.

9. Mention any two differences between prokaryotic and eukaryotic cells.

Ans: (i) Prokaryotic cells lack a nuclear membrane, while eukaryotic cells have a true nucleus.

(ii) Prokaryotic cells have no membrane-bound organelles; eukaryotic cells do.

10. What is the role of the nucleus in a cell?

Ans: The nucleus controls all cellular activities, stores genetic material (DNA), and helps in cell division and protein synthesis.

11. What are plastids? Name their two types.

Ans: Plastids are plant cell organelles. 

Two types are:

(i) Chloroplasts: For photosynthesis.

(ii) Leucoplasts: For storage of starch and proteins.

12: Give two functions of endoplasmic reticulum.

Ans: RER helps in protein synthesis.

SER helps in lipid synthesis and detoxification.

13. What is cell theory?

Ans: Cell theory states that:

(i) All living organisms are made up of cells.

(ii) The cell is the basic unit of life.

(iii) All cells arise from pre-existing cells.

14. Why do plant cells have larger vacuoles than animal cells?

Ans: Plant vacuoles help maintain turgidity, store important substances, and occupy up to 90% of the cell’s volume, which is not needed in animal cells.

15. Why is the plasma membrane called selectively permeable?

Ans: Because it allows only certain substances to pass in and out of the cell while restricting others based on size or charge.