- 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.
Answer:
D. organ systems
Explanation:
Organs and tissues that perform the same function are called organ systems
<span>In the sentence "Biologists recognize the following levels of cell organization: _____, the choice that correctly completes the sentence is b. cellular, tissue, organ, system, and organism. A cell is the basic unit of living organisms. The group of similar cells that work together to perform a specific job is a tissue. The group of multiple tissues joined together in the functional structure is an organ. Functionally related organs form organ systems, which all together form one organism.</span>
Answer: That translates to "Which is the potential for action" in English. I hope that is what you were looking for as I have nothing else to base your question off of, as you only put a line of Spanish as your question.
