Characteristics of Living Organisms

Living organisms are fascinating because they all share certain characteristics that set them apart from non-living things. Let’s explore these characteristics in a simple and friendly way. Imagine living organisms as tiny factories—each one busy performing essential tasks to stay alive. Here are the key characteristics:

 

Characteristics

1. Movement

Living things can move in some way. For example:

• Humans walk, run, and dance.

• Plants bend toward sunlight (this is called tropism).

2. Respiration

All living things need energy, and they get it through respiration. Respiration is like recharging a battery. For most organisms, this happens when they break down food and combine it with oxygen to release energy.

Formula for aerobic respiration: $$\text{Glucose} + \text{Oxygen} \rightarrow \text{Carbon Dioxide} + \text{Water} + \text{Energy (ATP)}$$

3. Sensitivity (Response to Stimuli)

Living organisms can sense changes in their environment and respond to them. For instance:

• You pull your hand away from something hot.

• A dog wags its tail when it’s happy.

Sensitivity is like having built-in sensors that help you react to what’s happening around you.

4. Growth

All living things grow. This could mean:

• A baby growing into an adult.

• A seed sprouting into a tree.

Growth is like adding building blocks to get bigger or stronger.

5. Reproduction

Living things can make more of their kind. This might be:

• Animals giving birth to young ones.

• Plants producing seeds.

Reproduction ensures that life continues from generation to generation.

6. Excretion

All living things produce waste that they need to get rid of. For example:

• Humans excrete sweat, urine, and carbon dioxide.

• Plants release oxygen as a byproduct of photosynthesis.

Excretion is like taking out the trash—it keeps the organism clean and functional.

7. Nutrition

Living organisms need nutrients to survive. For example:

• Humans eat food.

• Plants absorb water and minerals from the soil and make their own food through photosynthesis.

Nutrition is like fueling a car; without it, the engine won’t run!

Memory Aid: MRS GREN

An easy way to remember the seven characteristics of living organisms is the acronym MRS GREN:

• Movement

• Respiration

• Sensitivity

• Growth

• Reproduction

• Excretion

• Nutrition