Question

SAQ 4: Tissues

1          Explain the relationship between cells and tissues.

2          What is the definition of a meristem? Do any animals have Meristems?

3          What is the difference between primary and secondary growth in plants?

4          Complete the following chart using your knowledge of complex tissues.

Tissue	Function	Types of Cells	Location
Xylem			Stems, roots
Phloem	Conducts sugars, dissolved in water, throughout the plant
Epidermis	Protection , Gas exchange via stoma
Periderm

5          Name the 3 primary meristems that develop from apical meristems and the structures that they will eventually produce.

6          Name the 2 Lateral meristems and the structures that they will eventually produce.

Answer 1

1) cells are the building blocks of life. A group of similar cells work together, known as tissue. All the cells in a tissue see the same and perform the same job.The relation between specialized cells and tissues is that tissues are made of specialized cells that work together.

2) A meristem is the tissue, which is present in plant. It contains undifferentiated cells. It is found in areas of the plant where growth occurs. Meristematic cells give rise to various organs of the plant and keep the plant growing. A plant has kinds of meristems: the apical meristem and three kinds of lateral—vascular cambium, cork cambium, and intercalarymeristem.

The meristematic cells are frequently compared to the stem cells in animals, which have an analogous behavior and function.

3) Primary growth and secondary growth are the two mechanisms by which woody plants increase its size.

Apical meristematic cell division leads to primary growth results in increase in length of the plants.

lateral meristematic cell division leads to secondary growth results in increase in girth of the plants.

4)

Tissue	Function	Types of Cells	Location
Xylem	Transports water and soluble mineral nutrients from the roots throughout the plant. It is also used to replace water lost during the process of transpiration and photosynthesis.	Tracheids, vessel elements ,parenchyma and fibers.	Stems, roots
Phloem	Conducts sugars, dissolved in water, throughout the plant	Sieve tubes, companion cells, phloem fibres, and phloem parenchyma cells.	Stems, roots
Epidermis	Protection , Gas exchange via stoma	Epidermal cells, guard cells, subsidiary cells, and trichomes.	Leaves, flowers, roots and stems
Periderm	Reduces water loss with the help of evaporation, but allows gaseous exchange through lenticels. It protects functional secondary phloem and inner living tissues from drying out, mechanical injury and temperature extremes. It replaces the epidermis of roots and stems, which is shed.	Parenchyma cells and composed of phellogen, phellem, and phelloderm.	Inside of cork cambium