Advertisements
Advertisements
प्रश्न
Explain how sieve tubes manage to be living?
Advertisements
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
APPEARS IN
संबंधित प्रश्न
Identify the type of tissue in the bark of tree.
Complete the following chart:
What are the functions of xylem?
What is simple tissue? Classify and explain its different types with suitable diagram.
Write 'True or False' for the following statement:
A tracheid is longer than a vessel.
The question has four answers. Choose the correct answer:
Phloem parenchyma, sclerenchyma, sieve tubes, and companion cells are found in
Which of the following is a permanent tissue?
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 ______.
In which of the following pairs of parts of a flowering plant is epidermis absent?
