Very Short Answer Questions - 1 Mark

Q. 1. Plasma membrane is made up of which two components?

Ans. Plasma membrane is made up of lipids and proteins.

Q. 2. What is hypotonic solution?

Ans. A solution having solute concentration lower than that of the cell sap is called hypotonic solution.

Q. 3. What is hypertonic solution?

Ans. A solution having solute concentration higher than that of the cell sap is called hypertonic solution.

Q. 4. What is isotonic solution?

Ans. A solution having solute concentration same as that of the cell sap is called isotonic solution.

Q. 5. Cell wall is made up of which component?

Ans. Cell wall is made up of cellulose.

Q. 6. Give an example of unicellular organism.

Ans. Amoeba, Bacteria, Paramecium. (Any one)

Q. 7. Give an example of multicellular organism

Ans. Fungi, plants, animals. (Any one)

Q. 8. What is active transport?

Ans. The movement of molecules across a membrane in cells against a concentration gradient with the help of ATP units is called active transport.

Q.9. What is the intracellular source of digestive enzyme?
Ans. Lysosome

Q. 10. What is endocytosis?

Ans. Endocytosis is the ingestion or engulfment of food and other material by folding of the plasma membrane it as seen in Amoeba.

Q. 11. Where are genes located?

Ans. Genes are located on chromosomes in the nucleus.

Q. 12. Name two structures found in plant cells but not in animal cells.

Ans. Cell wall and chloroplast

Q. 13. Name two structures found in animal cells but not in plant cells.

Ans. Lysosomes and centrioles

Q.14. Which organelle is involved in the formation of lysosomes?

Ans. Golgi apparatus

Q. 15. what is the outermost layer found in animal cells?

Ans. Plasma membrane

Q. 16. What is the outermost layer found in the plant cell?

Ans. Cell wall

Q. 17. Which organelle is the storage sac of solid and liquid materials?

Ans. Vacuoles

Q.18. Which organelle serves as a channel for transport of materials between cytoplasm and nucleus?

Ans. Endoplasmic reticulum

Q. 19. What is microscope?

Ans. Microscope is an optical instrument consisting of a lens or combination of lenses which renders minute objects distinctly visible.

Q. 20. Why is light microscope called a compound microscope?

Ans. Light microscope is called a compound microscope because it consists of two or more lens systems.

Q. 21. Which organelle is associated with ribosome formation?

Ans. Nucleolus

Q. 22. What are chromosomes made up of?

Ans. Chromosomes are made up of DNA and protein.

Q. 23. Define plasmolysis.

Ans. It is the shrinkage of cytoplasm due to loss of water when kept in a hypertonic medium.

Q. 24. What is a nucleoid?

Ans. the undefined nuclear region in the cytoplasm of prokaryotes is known as nucleoid.

Q. 25. Which organelles other than nucleus contain DNA?

Ans. Mitochondria and plasmids contain DNA.

Q. 26. Name the only cell organelle seen in prokaryotic cell.

Ans. Ribosomes

Q.27. Which microorganisms can be made into crystal?

Ans. Viruses

Q. 28. Which organelle detoxify many poisons and drugs in a cell?

Ans. Peroxisome

Q.29. Name a cell organelle which is non-membranous.

Ans. Ribosome.

Q. 30. Define diffusion.

Ans. Movement of molecules from a region of higher concentration to a region of lower concentration is called diffusion.

Q.31. Why is endocytosis found in animals only?

Ans. For endocytosis to occur, the outermost membrane should be flexible like the plasma membrane of animals. But in plant cells, cell wall is the outermost membrane which is very rigid. Hence, endocytosis occurs only in animals and not in plants.

Q.32. Which cell organelle controls most of the activities of the cell?

Ans. Nucleus, also known as the brain of the cell, controls most of the activities of the cell because it contains DNA (Deoxyribonucleic acid) which contains all the information of the cell.