- Xylem contains tracheids, vessels, xylem parenchyma and xylem fibre.
- Tracheids: They are elongated, tubular dead cells with tapering end walls.
- Vessels: These are also known as trachea. They are elongated, tubular dead cells. They are joined to each other by end to end forming a continuous pipe. The cells are thick and lignified.
- Xylem parenchyma: They are also called wood parenchyma. This is the only living tissue of xylem.
- Xylem fibre: They are dead cells with thick walled fibre.
- Phloem consists of sieve tubes, companion cells, phloem parenchyma and phloem fibres.
- Sieve tubes: These are elongated, tubular living cells arranged in a row, with their perforated end walls forming a sieve. They are non-nucleated. Their protoplasm are inter-connected through sieve plates. They possess vacuoles.
- Companion cell: They are elongated, lens-shaped cells containing dense cytoplasm and prominent nuclei. These cells maintain connection with sieve cells through pits.
- Phloem parenchyma: They are living thin walled parenchyma cells.
- Phloem fibre: They are also known as bast fibre. They are elongated fibre like sclerenchymatous dead cells with thick walls containing pits and interlocked ends. Phloem fibre are the only dead cells in phloem.
Hope you could get an idea from here.
Doubt clarification - use comment section.
Prokaryotic cellss are unicellular and therefore have no organelles and no true nucleus whereas eukaryotic cells have organelles and a nucleus. Therefore the first one is eukaryotic and then second is prokaryotic
Answer:
Enzymes help speed up chemical reactions in the human body. They bind to molecules and alter them in specific ways. They are essential for respiration, digesting food, muscle and nerve function, among thousands of other roles.
Answer:
Four satellites are needed to find your location. GPS's get the signal from satellites and that can calculate the distance you are from those satellites and location. the satellites emit high frequency low power signals that your GPS can pick up.
Explanation:
B.produce antibodies when triggered by antigens
