Cell Wall - Composition and Function - UNSOLVED PRACTICE SET
Chapter: The Fundamental Unit of Life | Topic: Cell Wall Composition and Function
CELL WALL - COMPOSITION AND FUNCTION - UNSOLVED PRACTICE SET
Topic: Cell Wall Composition and Function
Multiple Choice Questions
Q1. The primary component of the plant cell wall is:
- Peptidoglycan
- Chitin
- Cellulose
- Lipids
Q2. The cell wall of fungi is composed of:
- Cellulose
- Chitin
- Peptidoglycan
- Pectin
Q3. Which of the following organisms does NOT have a cell wall?
- Bacterium
- Fungus
- Animal cell
- Plant cell
Q4. The cell wall of bacteria contains:
- Cellulose and lignin
- Chitin and glucans
- Peptidoglycan (murein)
- Pectin and hemicellulose
Q5. The middle lamella, which cements adjacent plant cells together, is rich in:
- Cellulose
- Lignin
- Calcium pectate
- Suberin
Short Answer Questions
Q6. Describe the composition and structure of the plant cell wall. Mention the three layers.
Q7. Differentiate between the cell wall composition of plants, fungi, and bacteria.
Q8. What is lignin? In which type of plant cells is it deposited, and what is its function?
Q9. Explain why animal cells do not have a cell wall. How do they maintain their shape without it?
Long Answer Questions
Q10. Draw a well-labelled diagram showing the structure of a plant cell wall. Label the middle lamella, primary cell wall, secondary cell wall, plasmodesmata, and mention the composition of each layer.
Q11. Explain the various functions of the cell wall in plant cells. How does the cell wall contribute to the overall growth and development of the plant?
APPLICATION / ANALYSIS
Q12. A farmer notices that his wheat crop is lodging (falling over) during heavy rains. A fellow farmer suggests using silicon-based fertilizers to strengthen the plants.
(a) How does silicon deposition in cell walls help plants resist lodging?
(b) Why are grasses (like wheat) more prone to lodging than trees?
(c) If you were to examine the cell walls of wheat stems under a microscope before and after silicon treatment, what differences would you expect to see?
Q13. Penicillin is an antibiotic that works by inhibiting the synthesis of peptidoglycan in bacterial cell walls.
(a) Why does penicillin kill bacteria but not harm human cells? Explain with reference to cell wall composition.
(b) Some bacteria have developed resistance to penicillin by producing enzymes called beta-lactamases. Predict how these enzymes might help the bacteria survive.