Sketch, label and describe T.S. of Typical dicot stem.
Answers
Explanation:
The cells in typical dicot stem are closely packed. There are 4 types of tissues. Those are
1. DERMAL TISSUE :
This tissue forms outer coverings. This tissue usually consists of a single layer of tissues showing variations in the types of cells on the basis of their functions and location. This tissues are divided into 3 different types. They are
1. Epidermis : outermost layer
2. Mesodermis : middle layer
3. Endodermis : innermost layer
The walls of the cells of this tissue are comparatively thicker than the cells of meristematic tissue. Small pores are seen in the epidermis of the leaf called stomata.
2. MERISTEMATIC TISSUE :
This tissue bring about overall growth and repair. This tissue is of 3 types.
1. APICAL MERISTEMATIC TISSUE :
The meristematic tissue at the growing tip that bring about growth in length is apical meristematic tissue.
2. LATERAL MERISTEMATIC TISSUE:
TISSUE present around the edges in a lateral manner and giving raise to growth in the girth of stem is lateral meristematic tissue.
3. INTERCALARY MERISTEMATIC TISSUE or CAMBUIM MERISTEM :
areas from which branching takes place or a leaf or a flower stalk grows that type of tissue is INTERCALARY meristematic tissue.
3. Ground tissue :
TISSUE that forms bulk of the plant body, helping in packing other tissues are called ground tissues. This tissue is of 3 types :
1. PARENCHYMA :
The cells are very small with thin cell wall. This type of this tissue is of 3 types :
1. CHLORENCHYMA :
Helps in preparing food
2. AERENCHYMA :
Help aquatic plants to float
3. STORAGE TISSUE :
Helps in storing food, water and even waste to be excreted
2. COLLENCHYMA :
These cells have thick cell wall compared to parenchyma and give mechanical strength
3. SCLERENCHYMA :
these cells have thick cell wall compared to collenchyma. They give tensile strength and flexibility.
4. VASCULAR TISSUE :
This tissue helps in transportation of food, water, etc....... This tissue is of 2 types :
1. XYLEM :
Helps in conduction of water and minerals from roots to all the parts of the plant. Cells in xylem are tracheid cells, tubular vessels, fibres and parenchyma.
2. PHYLUM :
This tissue conducts food from leaves to all parts of the plant. Cells in phylum are long sieve cells, companion cells, fibres and parenchyma
Explanation:
To look at the typical dicot stem we take the example of the young sunflower stems. if a uniform and a thin section of the sunflower is taken and observed under the microscope. the first layer is called epidermis. it is the outermost layer or the skin of the sunflower. it is single layered and consists of tabular parenchyma cells.