Class 9 Science Tissue Extra Question Answer
1. What is a tissue?
A tissue is a group of cells that are similar in structure and function, working together to perform a specific activity.
2. What is the main difference between unicellular and multicellular organisms regarding tissues?
Unicellular organisms perform all functions within a single cell, while multicellular organisms have specialized groups of cells forming tissues for efficient functioning.
3. What are the two main types of plant tissues?
Plant tissues are classified into meristematic tissue, which divides throughout the plant’s life, and permanent tissue, which does not divide and is specialized for different functions.
4. What is meristematic tissue?
Meristematic tissue consists of actively dividing cells, located in specific areas of the plant, contributing to growth.
5. What are permanent tissues?
Permanent tissues develop from meristematic tissues after losing their ability to divide and can be classified into simple and complex tissues.
6. Provide examples of simple permanent tissues.
Simple permanent tissues include parenchyma, collenchyma, and sclerenchyma, which consist of similar types of cells.
7. What is sclerenchyma tissue?
Sclerenchyma is a type of plant tissue that provides strength and stiffness; its cells are dead and have thickened walls rich in lignin.
8. What are complex tissues in plants?
Complex tissues, such as xylem and phloem, are made up of more than one type of cell working together to perform common functions like transport.
9. What role does xylem play in plants?
Xylem transports water and minerals from the roots to other parts of the plant and provides structural support.
10. Describe the function of phloem.
Phloem transports nutrients, primarily food produced by photosynthesis, from leaves to other parts of the plant.
11. How do animal tissues differ from plant tissues?
Animal tissues are more diverse and include epithelial, connective, muscular, and nervous tissues, reflecting their mobile and complex structure compared to plants.
12. What is the primary role of epithelial tissue?
Epithelial tissue protects surfaces, forms barriers, and is involved in absorption, secretion, and sensation.
13. What is muscular tissue responsible for?
Muscular tissue consists of cells that can contract and relax, allowing movement of the body and its parts.
14. What are the three types of muscular tissue?
The three types of muscular tissue are skeletal (voluntary), smooth (involuntary), and cardiac (heart muscle).
15. What distinguishes cardiac muscle cells from others?
Cardiac muscle cells are striated, involuntary, and interconnected, allowing them to contract rhythmically.
16. Explain the function of nerve tissue.
Nerve tissue, composed of neurons, is responsible for transmitting signals throughout the body, facilitating communication and coordination.
17. What is the fluid matrix in blood?
Blood has a fluid matrix called plasma, which suspends red blood cells, white blood cells, and platelets, and carries nutrients and waste products.
18. What are tendons and ligaments?
Tendons connect muscles to bones, providing strength, while ligaments connect bones to other bones, allowing flexibility.
19. What is areolar connective tissue, and where is it found?
Areolar connective tissue is loose connective tissue found between skin and muscles, around blood vessels and nerves, and in bone marrow, supporting internal organs.
20. Where is adipose tissue located, and what is its function?
Adipose tissue, or fat tissue, is located beneath the skin and around internal organs, serving to store energy and provide insulation.
21. What is the purpose of guard cells?
Guard cells regulate the opening and closing of stomata, facilitating gas exchange and transpiration in plants.
22. What role does cartilage play in the body?
Cartilage provides cushioning and flexibility at joints, smooths bone surfaces, and is found in structures like the nose and ears.
23. How do animal tissues adapt to their lifestyle compared to plant tissues?
Animal tissues are designed for movement and varied functions due to active locomotion, while plant tissues are structured to maintain stability and support growth.
24. Why is blood considered a connective tissue?
Blood is classified as a connective tissue because it connects different body systems through transport and distribution of nutrients and waste products.
25. What is the significance of the thickened walls in sclerenchyma cells?
The thickened walls of sclerenchyma cells provide structural support and rigidity, essential for the plant’s growth and stability.
