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प्रश्न
Explain how sieve tubes manage to be living?
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उत्तर
Sieve tube elements of phloem tissue lack nucleus but still they manage to live. This is because they are connected to the companion cells of phloem tissue via numerous plasmodesmata. Both sieve tube elements and companion cells develop from the same meristematic cell and form a functional unit. Companion cells provide proteins, ATP, and other signalling molecules to the sieve tube member as it contains extra number of mitochondria and ribosomes
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संबंधित प्रश्न
Draw a well labelled diagram of xylem.
Give two functions of collenchyma.
Write a short note on sclerenchyma.
What are the functions of xylem?
Study the diagram given below and then answer the question that follows:
Where is this tissue likely to be found in the plant?
A permanent tissue is of how many types?
The question has four answers. Choose the correct answer:
A component of xylem is
Name the two types of sclerenchyma cells.
Match the followings and choose the correct option from below
| Column I | Column II |
| A. Meristem | i. Photosynthesis, storage |
| B. Parenchyma | ii. Mechanical support |
| C. Collenchyma | iii. Actively dividing cells |
| D. Sclerenchyma | iv. Stomata |
| E. Epidermal tissue | v. Sclereids |
Cells of this tissue are living and show angular wall thickening. They also provide mechanical support. The tissue is ______.
