Class 9 Science Chapter-2 Cell: The Building Block of Life
MCQ Questions with Answers (Part-3)
1. What is the process of growing plant and animal cells outside the body in a nutrient-rich medium under sterile conditions called?
C) Cell culture
2. In plants, where does meiosis specifically occur to form pollen grains?
D) Anthers
3. According to the fluid-mosaic model of the cell membrane, how are the lipid bilayer molecules arranged?
B) Water attracting heads outwards, water repelling tails inwards
4. The plant cell wall is primarily made of which complex carbohydrate that also acts as roughage in the human diet to help with digestion?
C) Cellulose
5. What is the meaning of the Greek words "eu" and "karyon" in the term "eukaryotic"?
B) True and nucleus
6. Which specific dense, round structure within the nucleus is responsible for the synthesis of ribosomal subunits?
A) Nucleolus
7. While errors in mitosis lead to tumours, errors in which type of cell division can specifically result in genetic disorders, developmental problems, or reduced fertility?
B) Meiosis
8. When preparing a temporary slide of a plant cell, such as a thin peel of an onion or a Rhoeo leaf, which stain is typically used?
C) Safranin
9. In a eukaryotic cell, what is the double-layered covering that features pores to allow the transfer of material between the nucleus and the cytoplasm?
C) Nuclear membrane
10. In the two-step process of meiosis, what happens to the number of chromosomes in each daughter cell during the first division?
D) It is reduced to half.
11. Which type of bacteria are mostly found living in the extremely hot springs of Puga Valley in Ladakh?
C) Thermophiles
12. Approximately how long ago were the environmental conditions on early Earth similar to those found in hot springs today?
C) 3.5 billion years ago
13. Scientists from the Birbal Sahni Institute of Palaeosciences discovered that early organic molecules might have been protected by deposits of:
A) Calcium carbonate
14. Which of the following best defines a "tissue" in a multicellular organism?
B) A group of similar cells performing similar functions
15. When using a light microscope, what three main features have scientists improved over the years to make it a more powerful tool?
B) Resolution, contrast, and magnification
16. What is the term for the net movement of particles from an area of higher concentration to an area of lower concentration, which can occur even without a membrane?
C) Diffusion
17. During an experiment preparing a temporary mount of a human cheek cell, which of the following is typically used to stain the cells?
B) Methylene blue
18. What happens to the inner content of a Rhoeo leaf cell when it is placed in pure water?
C) It remains firm as water enters the cell, but its shape is maintained by the cell wall.
19. In the fluid-mosaic model, why is the cell membrane described as "fluid"?
B) Because the lipid and protein molecules can move sideways, flip, and rotate within the membrane.
20. What is the typical diameter range of a prokaryotic cell?
B) 1 to 10 µm
21. In a eukaryotic cell, the endoplasmic reticulum (ER) forms a continuous network with which other cellular structure?
B) The outer membrane of the nuclear envelope
22. Where do the large and small subunits of ribosomes actually assemble to form a complete, functional ribosome?
B) In the cytoplasm
23. Approximately how long do mature human Red Blood Cells (RBCs) survive in the body before they die and need to be replaced?
C) 120 days
24. What is the term for the unorganised, entangled mass of thread-like DNA structures found in a cell that is not dividing?
D) Chromatin material
25. Which of the following organelles breaks down unwanted proteins, carbohydrates, fats, and damaged cell parts, releasing their products into the cytoplasm for reuse?
B) Lysosomes
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