Réponse:
(c) red blood cell (d) nerve cell
7. The nucleus of the cell was discovered by
(a) Robert Hooke (b) Leeuwenhoek
(c) Robert Brown (d) Purkinje
8. The plant cells are more rigid than the animal cell due to
(a) cell wall (b) vacuoles
(4 plastids (d) both (a) and (b)
9. The opening and closing of stomata is due to
(a) sunlight (b) osmosis
(4 plasmolysis (d) endocytosis
10. The cells with jio membrane bound organelles, and the chromosomes are composed of only nucleic acids are
(a) plant cells (b) animal cells
(c) prokaryotic cells (d) eukaryotic cells
Answer. 1—(c), 2—(d), 3—(4. 4—(c), 5—(b), 6—(c), 7—(4, 8—(d), 9—(b), 10—(c).
NCERT Solutions For Class 9 Science Chapter 5 Very Short Answer Type Questions
Question 1. What are plastids? Name the different types of plastids found in a plant cell.
Answer: Plastids are organelles found only in plants. They are:
(a) Chloroplast-Containing chlorophyll
(b) Chromoplast-Containing carotenoids and xanthophyll (coloured plastids)
(c) Leucoplast-Wllite or colourless plastids
Question 2. What is plasma membrane made up of?
Answer: Plasma membrane is made up of proteins and lipids.
Question 3. What did Robert Hooke observed first in cork cell?
Answer: Robert Hooke observed that cork consists of box like compartments which formed a honeycomb structure.
Question 4. Name the autonomous organelles in the cell.
Answer. Chloroplasts and mitochondria are the autonomous organelles in the cells.
Question.5. What does protoplasm refer to?
Answer: Protoplasm refer to cytoplasm and nucleus.
Question 6. Name two cells which keep changing their shape.
Answer: Amoeba and white blood cells.
Question 7. Name the smallest cell and the longest cell in human body.
Answer: The smallest cell is the red blood cell or sperm cell in male. Longest cell is the nerve cell.
Question 8. Name 3 features seen/present in almost every cell.
Answer: Plasma membrane, nucleus and cytoplasm.
Question 9.What is diffusion?
Answer: When gases like C02, 02, move across the cell membrane, this process is called diffusion.
Question 10.What is osmosis? This takes place from high water concentration to low water concentration.
Answer: The movement of water molecules through a selectively permeable membrane is called osmosis. This takes place from high water concentration to low water concentration.
Question 11. What is the full form of DNA?
Answer: DNA —> Deoxyribo Nucleic Acid.