The Fundamental Unit Of Life

Q1. Where are proteins synthesized inside the cell? 

Ans. Proteins are synthesized in the ribosomes.

Q2. Name any cell organelle which is non-membranous.

Ans. Ribosomes are the non-membranous cell organelles.

Q3. What is the primary function of leucoplasts?

Ans. The primary function of leucoplasts is storage.

Q4. Name some single celled organisms.

Ans. Amoeba, Chlamydomonas, Paramoecium and bacteria

Q5. Where do the lipids and proteins constituting the cell membrane get synthesised? 

Ans. Lipids and proteins are synthesised in ER [Endoplasmic Reticulum].

Q6. Can you name the two organelles we have studied that contain their own genetic material?

Ans. Mitochondria, Chloroplasts (plastids)

Q7. Chromosomes are made up of

(a) DNA

(b) protein

(c) DNA and protein

(d) RNA.

Ans. (c) DNA and protein

Q8. Kitchen of the cell is

(a) mitochondria

(b) endoplasmic reticulum

(c) chloroplast

(d) Golgi apparatus.

Ans. (c) chloroplast

Q9. Silver nitrate solution is used to study

(a) endoplasmic reticulum

(b) Golgi apparatus

(c) nucleus

(d) mitochondria.

Ans. (b) Golgi apparatus

Q10. 1 µm is

(a) 10^-6m

(b) 10^-9m

(c) 10^-10m

(d) 10^-3m

Ans. (a) 10^-6m

Q11. Name the two organelles in a plant cell that contain their own genetic material and ribosomes.

Ans. Mitochondria and plastids also have their own DNA and ribosomes.

Q12. Which of the following are covered by a single membrane?

(a) Mitochondria

(b) Vacuole

(c) Lysosome

(d) Plastid

Ans. Both (b) and (c)) 

Both vacuole and lysosome are single membrane bound cell organelles. 

Q13. Bacteria do not have chloroplast, but some bacteria are photoautotrophic in nature and perform photosynthesis. Which part of bacterial cell performs this?

Ans. Photoautotrophic bacteria possess photosynthesis pigments inside small vesicles which may be attached to the plasma membrane.

Q14. If the organisation of a cell is destroyed due to some physical or chemical influence, what will happen?

Ans. If the organisation of a cell is destroyed, lysosomes may burst and the enzymes digest their own cell.

Q15. Lysosome arises from

(a) endoplasmic reticulum ,

(b) Golgi apparatus

(c) nucleus

(d) mitochondria.

Ans. (b) Golgi apparatus

The Golgi apparatus is involved in the formation of lysosomes.

Q16. What is osmosis? 

Ans. Water also obeys the law of diffusion. The movement of water molecules through a selectively permeable membrane is called osmosis.

Q17. Organelle other than nucleus, containing DNA is

(a) endoplasmic reticulum

(b) Golgi apparatus

(c) mitochondria

(d) lysosome.

Ans. (c) mitochondria

Explanation:

Mitochondria and plastids have their own DNA and ribosomes.

Q18. Which kind of plastid is more common in

(a) roots of the plant

(b) leaves of the plant

(c) flowers and fruits. 

Ans. (a) roots – Leucoplasts

(b) leaves – Chloroplasts

(c) flowers and fruits - Chromoplasts

Q19. A cell will swell up if

(a) the concentration of water molecules in the cell is higher than the concentration of water molecules in surrounding medium

(b) the concentration of water molecules in surrounding medium is higher than water molecules concentration in the cell

(c) the concentration of water molecules is same in the cell and in the surrounding medium

(d) concentration of water molecules does not matter

Ans. (b) the concentration of water molecules in surrounding medium is higher than water molecules concentration in the cell

Q20. Why are lysosomes known as suicide bags?

Ans. When the cell gets damaged, lysosomes may burst and the enzymes digest their own cell. Therefore, lysosomes are also known as the ‘suicide bags’ of a cell. 

Q21. Cell arises from pre-existing cell was stated by

(a) Haeckel

(b) Virchow

(c) Hooke

(d) Schleiden.

Ans. (b) Virchow

Explanation:

The cell theory was further expanded by Virchow (1855) by suggesting that all cells arise from pre-existing cells.

Q22. Living cells were discovered by

(a) Robert Hooke

(b) Purkinje

(c) Leeuwenhoek

(d) Robert Brown.

Ans. (c) Leeuwenhoek

Explanation:

Leeuwenhoek (1674), with the improved microscope, discovered the free living cells in pond water for the first time.

Q23. Which of these is not related to endoplasmic reticulum?

(a) It behaves as transport channel for proteins between nucleus and cytoplasm.

(b) It transports materials between various regions in cytoplasm.

(c) It can be the site of energy generation.

(d) It can be the site for some biochemical activities of the cell.

Ans. (c) It can be the site of energy generation.

Explanation:

The endoplasmic reticulum (ER) functions both as a passageway for intracellular transport and as a manufacturing surface.

Q24. Write the name of different plant parts in which chromoplast, chloroplast and leucoplast are present.

Ans. Chromoplast – Flowers and Fruits

Chloroplast – Green leaves and green parts

Leucoplast – Root and underground stem