- 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.
The connective tissues and the epithelial tissue differ in their structure in the way their cells are organized. The cell of the epithelial tissue are organized in a closed-packed pattern, while the cells of connective tissue are organized in spread out pattern. Moreover, the connective tissues has blood vessels, but the epithelial tissue does not.
The epithelial tissues serve the purpose of protection. Protective layering is formed by the epithelial tissues in the body. The connective tissue such as bone provides support to the body. The blood vessel connectivity helps in the transfer of the newly formed blood cells.
The appearance of a person is determined by the tissues and other components. The skeletal determines the basic structure of the person. The epithelial tissues give more specificity to the figure of a person. The fats helps in determining the shape of the eyes and cheeks.
The fat in the cheeks is supposed to help the new born infants to suckle and chew. Moreover, it provides padding to the temporalis muscle while chewing. The fat behind the eyes helps in preventing damage to the eyes which may be caused if they rub with the bones of the skull.
It will be hard to open and close one's mouth if the temporalis muscle of a person is damaged. This will make forming words properly difficult. The damage to orbicularis oculi will make the blinking extremely difficult. The facial expressions will be distorted in such cases. The damage to the orbicularis oris will make the movement of the mouth difficult, which will cause poor articulation.
Lycopodium is a family of fern-allies .
They are mostly a flowerless plants with widely branched, with little and simple,
needle-like like leaves that
cover the branches thickly and stem while Equisetum usually called horsetail, snake
grass because it more like a tail of a horse and its the only living genus in Equisetaceae,
a family of vascular
plants that reproduce by spores rather than
seeds.
Maps are examples of physical models
