Summary
Summary CHAPTER-01 THE LIVING WORLD CBSE Quick Revision Notes (Class-11 Biology)
- Course
- Institution
CHAPTER-01 THE LIVING WORLD CBSE Quick Revision Notes (Class-11 Biology)
[Show more]
Content preview
CBSE Quick Revision Notes (Class-11 Biology)CHAPTER-01 THE LIVING WORLD
Life is a unique, complex organization of molecules that expresses itself through
chemical reactions which lead to growth, development, responsiveness, adaptation and
reproduction.
The objects exhibiting growth, development, reproduction, respiration, responsiveness
and other characteristics of life are designated as living beings.
Unique features of living organism:-
(a) Growth- Living organisms grow in mass and number. A multicellular organism
increases its mass by cell division. In plants growth continuous throughout life in
their meristemtic area but in animals, growth occurs to a certain age. Unicellular
organisms also grow by cell division. Living organisms show internal growth due to
addition of materials and formation of cells inside the body. Non living organism like
mountains, boulders, crystals also grow but due to addition of similar materials to
their outer surface.
(b) Reproduction- It is the formation of new individuals of the similar kind. Reproduction
is not essential for survival of the individuals. It is required for perpetuation of the
population. In sexual reproduction two parents are involved to produce more or less
similar kinds of individuals. In asexual reproduction single parent is involved and
individual is copy of the parent. Asexual reproduction may occurs by fission,
fermentation, regeneration, vegetative propagation etc. In unicellular organism,
growth and reproduction are synonyms. Many organisms like mules, sterile worker
bees, infertile human couples. Therefore, reproduction is not an all-inclusive
characteristic of living organism. However, no nonliving object has the power to
reproduce or replicate.
(c) Metabolism- The sum total of all types of chemical reactions occurring in an
individual due to specific interactions amongst different types of molecules in the
interior of cells is called metabolism. All activities of an organism including growth,
movements, development, reproduction etc. are due to metabolism. There are two
types of metabolism- Catabolism and Anabolism. Anabolism includes all the building
up reactions to increase the mass of the organism like photosynthesis. In catabolism
breakdown reactions are involved, such as respiration, digestion etc. no nonliving
object show metabolism.
(d) Consciousness- It is the awareness of the surroundings and responding to external
stimuli. External stimuli may be physical, chemical or biological. Plants also responds
to stimuli like light, water, gravitation, pollution etc. All living organisms prokaryotic
to eukaryotic responds to different kinds of stimuli. Human being is only organism
who is aware of himself. Consciousness therefore, becomes the defining property of
living organisms.
(e) Life span- every living organism has a definite life span of birth, growth, maturity,
senesce and death.
Portal for CBSE Notes, Test Papers, Sample Papers, Tips and Tricks
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller lennyjast. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67474 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now