Page 103 - NCERT Science Class 10 English Medium

Think it over! 5.5.2 Excretion in Plants
Plants use completely different
Organ donation
strategies for excretion than those
Organ donation is a generous act of donating an of animals. Oxygen itself can be
organ to a person who suffers from non-function of thought of as a waste product
organ(s). Donation of an organ may be done by the generated during photosynthesis!
consent of the donor and his/her family. Anyone We have discussed earlier how
regardless of age or gender can become an organ plants deal with oxygen as well as
and tissue donor. Organ transplants can save or CO . They can get rid of excess water
transform the life of a person. Transplantation is 2
by transpiration. For other wastes,
required because recipient’s organ has been plants use the fact that many of
damaged or has failed by disease or injury. In organ their tissues consist of dead cells,
transplantation the organ is surgically removed
and that they can even lose some
from one person (organ donor) and transplanted to parts such as leaves. Many plant
another person (the recipient). Common
transplantations include corneas, kidneys, heart, waste products are stored in
liver, pancreas, lungs, intestines and bone marrow. cellular vacuoles. Waste products
Most organ and tissue donations occur just after may be stored in leaves that fall off.
the donor has died or when the doctor declares a Other waste products are stored as
person brain dead. But some organs such as resins and gums, especially in old
xylem. Plants also excrete some
kidney, part of a liver, lung, etc., and tissues can be
donated while the donor is alive. waste substances into the soil
around them.

Q U E S T I O N S

?
1. Describe the structure and functioning of nephrons.
2. What are the methods used by plants to get rid of excretory products?
3. How is the amount of urine produced regulated?

What you have learnt

n Movement of various types can be taken as an indication of life.
n Maintenance of life requires processes like nutrition, respiration, transport of
materials within the body and excretion of waste products.
n Autotrophic nutrition involves the intake of simple inorganic materials from the
environment and using an external energy source like the Sun to synthesise complex
high-energy organic material.
n Heterotrophic nutrition involves the intake of complex material prepared by other
organisms.
n In human beings, the food eaten is broken down by various steps along the
alimentary canal and the digested food is absorbed in the small intestine to be sent
to all cells in the body.

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