Biology Notes

Unit 1
Introduction to Biology
Detailed Notes
1. Biology
Biology is the scientific study of life and living organisms. It deals with the structure,
organization, functions, growth, reproduction, heredity, evolution, and interactions of living
organisms with their environment.

The word Biology is derived from two Greek words:

 Bios = Life
 Logos = Study or knowledge

So, Biology literally means the study of life.

Biology helps us understand organisms ranging from tiny microorganisms to large plants,
animals, and humans.




2. Major Branches of Biology
Biology is divided into many branches because living organisms and their activities are very
complex.

2.1 Botany

Botany is the branch of biology that deals with the study of plants.

It includes:

 Plant structure
 Plant growth
 Plant reproduction
 Plant classification
 Plant diseases
 Plant physiology

, Example: Studying how a plant absorbs water from the soil.



2.2 Zoology

Zoology is the branch of biology concerned with the study of animals.

It includes:

 Animal structure
 Animal behavior
 Animal classification
 Animal reproduction
 Animal evolution
 Animal physiology

Example: Studying the behavior of birds.



2.3 Microbiology

Microbiology is the study of microscopic organisms.

These include:

 Bacteria
 Some fungi
 Protozoa
 Microscopic algae
 Other microscopic biological agents

Example: Studying bacteria that cause diseases.



2.4 Cell Biology

Cell Biology is the study of the cell, its structure, components, and functions.

It studies structures such as:

 Cell membrane
 Cytoplasm
 Nucleus