Question 4
What are the various types of cells present in xylem? Write their functions.
The various types of cells present in xylem are
- Xylem vessels — A xylem vessel is not one cell but a series of cells joined from end to end to form a long tube. Its function is transportation of water.
- Tracheids — Tracheids are usually long and narrow cells that taper at the ends. Both tracheids and vessels do not have living protoplasm at maturity. They are involved in the transportation of water from the roots to the upper parts of the plant.
- Fibres — Fibres provide strength to the tissue. They also lack living protoplasm at maturity.
- Xylem parenchyma — Xylem parenchyma is the only living component of xylem. It helps in the conduction of water and also stores food.
Chapter 4: Tissue — ICSE Class VII Biology Notes
Complete ICSE Class VII Biology notes on Tissue covering meristematic and permanent plant tissues (parenchyma, collenchyma, sclerenchyma, xylem, phloem) and four animal tissue types with examples and diagrams.
Key Concepts and Topics
Topics covered: Meristematic tissue, Permanent tissue, Animal tissues, Xylem, Phloem
Weightage: Approximately 8 marks in the exam
Important Points to Remember
- Tissue: group of similar cells performing specific function
- Meristematic tissue: actively dividing cells at growth points
- Simple permanent: parenchyma (storage), collenchyma (flexibility), sclerenchyma (strength)
- Complex permanent: xylem (water up) and phloem (food both ways)
- Four animal tissues: epithelial, connective, muscular, nervous
- Three muscle types: skeletal, smooth, cardiac
- Blood is a connective tissue with liquid matrix
Frequently Asked Questions
Q: What is a tissue?
A: A tissue is a group of similar cells that perform a specific function together.
Q: What is the difference between xylem and phloem?
A: Xylem transports water upward and is made of dead cells. Phloem transports food in both directions and is made of living cells.
Q: Why is blood called a connective tissue?
A: Because it connects all body parts by transporting nutrients, oxygen, and waste, even though its matrix (plasma) is liquid.
Exam Preparation Tips
- Focus on understanding concepts rather than rote memorization
- Practice drawing and labelling diagrams regularly
- Use comparison tables for topics that require differentiation
- Solve previous year questions and practice papers
- Review the chapter notes provided by Bright Tutorials for comprehensive coverage
For complete chapter notes, practice questions, and test papers, contact Bright Tutorials at 9403781999.