Which of the following tissue are made up of dead cells?
A. Meristematic
B. Xylem vessels
C. Cambium
D. Mesophyll
Correct Answer:B
Explanation
The correct option is B. Xylem vessels.
Detailed Explanation:
Understanding Plant Tissues:
Plant tissues are broadly classified into two categories: meristematic and permanent tissues.
Meristematic tissues are composed of living cells that are actively dividing and are responsible for growth. Examples include the apical meristem and lateral meristem (cambium).
Permanent tissues are differentiated cells that have specific functions and can be further divided into simple and complex tissues.
Xylem Vessels:
Xylem is a type of complex permanent tissue responsible for the transport of water and minerals from the roots to the rest of the plant.
Xylem vessels are specifically made up of dead cells. These cells lose their cytoplasm and become hollow, forming long tubes that facilitate the upward movement of water through a process called transpiration.
The walls of xylem vessels are thickened with lignin, which provides structural support and prevents collapse under the negative pressure created during water transport.
Why Other Options Are Incorrect:
A. Meristematic: This option is incorrect because meristematic tissues consist of living cells that are actively dividing. They are responsible for the growth of the plant and are not made up of dead cells.
C. Cambium: Cambium is a type of meristematic tissue that is also made up of living cells. It is responsible for secondary growth in plants, producing new xylem and phloem cells. Therefore, it does not consist of dead cells.
D. Mesophyll: Mesophyll is a type of permanent tissue found in the leaves, primarily responsible for photosynthesis. It consists of living cells, including parenchyma cells that contain chloroplasts. Thus, it is not made up of dead cells.
Summary of Key Points:
Xylem vessels are made up of dead cells that transport water and minerals in plants.
Meristematic tissues (like cambium) consist of living cells and are involved in growth.
Mesophyll is a living tissue involved in photosynthesis, not composed of dead cells.
Understanding the functions and characteristics of different plant tissues is crucial for identifying their composition.
Revision Summary:
Xylem vessels are composed of dead cells for water transport.
Meristematic tissues (like cambium) are living and responsible for growth.
Mesophyll is a living tissue involved in photosynthesis.
Recognizing the differences between living and dead cell tissues is essential in plant biology.