Important NEET Biology: The Living World Study Materials & Notes Free PDF Download with NCERT Class 11 Chapter-wise MCQ Test & Quiz Series

The Living World Study Notes & Free Download Materials (NCERT Class 11 - Chapter: 1) - For NEET Biology Exam Preparation

Feb 21, 2023, 2024 by StudyTwice

In this article, we have complied with very important informations & Study materials on the "The Living World Topic" for the current NTA NEET UG 2024 Examination. Get complete syllabus based topic-wise seperate Practice Test Series, Daily MCQ Quizzes, & Study material notes for all NEET Biology Preparation which help to clear this year NEET exam 2024.

Life is a unique, complex organization of molecules, expressing through chemical reactions which lead to growth, development, responsiveness, adaptation and reproduction.

Life is a characteristic quality that differentiates inanimate (non-living) objects from the animate (living) forms.

PROPERTIES OF LIVING ORGANISMS

1. Growth

1. It is the increase in mass and number of cells.
2. In plants, growth by cell division occurs continuously throughout their life span.
3. In animals, growth is only up to a certain age. However, cell division occurs in certain tissues to replace lost cells.
4. Non-living objects grow by accumulation of material on the surface. In living organisms, growth is from inside.

2. Reproduction

1. It is the production of progeny similar to those of parents.
2. Organisms reproduce asexually and sexually.
3. Growth is the increase in cell number or mass. Hence in unicellular organisms, growth and reproduction are same.
4. Many organisms do not reproduce (e.g. mules, worker bees, infertile human couples, etc). Hence, reproduction is not a perfect defining characteristic of living organisms.

3. Metabolism

1. It is the sum total of all biochemical reactions taking place inside a living system.
2. Isolated metabolic reactions in vitro are not living things but are living reactions.

4. Cellular organization

1. All living organisms are made up of cells. They may be unicellular (single celled organism) or multicellular (multi celled organism).

5. Consciousness

1. It is this ability of organisms to sense their environment and respond to the environmental stimuli (like light, water, temperature, other organisms, chemicals, pollutants, etc.).
2. Therefore, all organisms are 'aware' of their surround- ings.
3. Human is the only organism having self-consciousness.

Levels of Organization

The living world can be organized into different levels. For example, many individual organisms can be organized into the following levels:

1. Cell: Cell is the basic unit of all living things.
2. Tissue: Tissues are group of cells of the same kind.
3. Organ: Organs are structure composed of one or more types of tissues.
4. Organ system: They are group of organs that work together to do a certain job.
5. Organism: Organisms constitutes individual living thing that may be made up of one or more organ systems.

There are also levels of organization above the individual organism. These levels are:

1. Population: Organisms of the same species that live in the same area make up a population. For example, all of the goldfish living in the same area make up a goldfish population.
2. Community: All of the populations that live in the same area make up a community. The community that includes the goldfish population lso includes the populations of other fish, coral, and other organisms.
3. Ecosystem: An ecosystem consists of all the living things in a given area, together with the non-living environment. The non-living environment includes water, sunlight, and other physical factors.
4. Biome: A group of similar ecosystems with the same general type of physical environment is called a biome.
5. Biosphere: The biosphere is the part of earth where all life exists, including all the land, water, and air where living things can be found. The biosphere consists of many different biomes.