Introduction:

In this chapter, we will explore the fascinating world of living things. Living things are everywhere around us, and they exhibit unique characteristics that set them apart from non-living things. Let’s delve into the key characteristics that define living organisms.

Characteristics of Living Things:

1. Cellular Structure:
Living things are composed of cells, the basic structural and functional units of life.
Some living organisms, like bacteria, are unicellular (made up of a single cell), while others, like plants and animals, are multicellular (made up of many cells).

2. Organization:
Living things have a high degree of organization in their structure, with cells organized into tissues, tissues into organs, and organs into organ systems.
This organized structure allows living organisms to carry out complex functions.

3. Growth:
Living things grow by increasing in size or by developing new structures.
Growth is often accompanied by an increase in the number of cells through cell division.

4. Reproduction:
Living things reproduce to ensure the continuation of their species.
Reproduction can be sexual, involving two parents, or asexual, involving a single parent.

5. Response to Stimuli:
Living organisms respond to stimuli from their environment.
Stimuli can be internal or external, and responses may include movement, changes in growth, or alterations in metabolic activities.

6. Metabolism:
Living things engage in metabolic activities, which include processes like digestion, respiration, and excretion.
Metabolism involves the conversion of food into energy for the organism’s survival.

7. Homeostasis:
Living organisms maintain internal stability through a process called homeostasis.
Homeostasis ensures that the internal conditions of an organism remain within a specific range for optimal functioning.

8. Adaptation:
Living things possess the ability to adapt to their environment over time.
Adaptations may be structural, behavioral, or physiological, allowing organisms to survive and thrive in various habitats.