TRANSPORTATION & EXCRETION
TRANSPORTATION & EXCRETION
Plants & animals both required food for; air & water for the maintenance & breeding of a cell. Each has to be supplied to the cell of the body in a right quantity .
The transport of material in plants is carried out by the vascular tissue.
A)Vascular Tissue :
There are 2 types of vascular tissues found in plants
- Xylem : Xylem transport water & nutrient upwards from the roots to the leave. Evaporation of water from the leaves during transpiration produces a pulling
force causing water to move up - Phloem : It carry the food prepared by the leaves during photosynthesis downward to all parts of the plants.
B) Transportation of water, minerals & food :
- The roots have root hairs which increase the surface area of the root for absorption of water & minerals dissolved in water. The root hair come in contact
with water present between soil particles.
C) Traspiration pulls :
- The water move from the root hair to the xylem in the root. The absorbed water then moves up the stem through the xylem by the force developed in the
leaves by the transpiration, called transpiration pull.
D) Ascent of sap :
- The fluid containing water & dissolved nutrient is called sap. The movement of sap through the xylem is called ascent of sap
E) Translocation :
- The food is transported from the leaves to other parts of the plant, called translocation.
EXCRETION IN PLANT
- Plants have no special organs for excretion. The excess amount of CO2 & water removed out through stomata also from the outer surface of stem, leave, fruit etc.
- Some waste products are colleced in vacuoles in the leaves & bark of trees & excrete them by shedding the leaves & barks
- Some waste products which are harmless, stored inside the plant body. Rubber raphides are examples of such products.
TRANSPIRATION
The process of loss of water in the form of vapours through the aerial parts of the plant is called transpiration.
TRANSPORTATION IN ANIMALS
In higher animals, digested food, gases & waste material are carried by blood. Blood flows through a network of tubes, which are called blood vessles & form a system known as circulatory system.
CIRCULATORY SYSTEM
It consist of heart, blood vessels & the blood.