•

29 Dec 2025

•

6 pages

Introduction to Biology: Understanding the Basics

evie

@e777

Biology is all about understanding how life works, from the... Show more

1 / 6

General Biology

Think of biology as the ultimate instruction manual for life itself. Every living thing follows the same basic rules, whether it's a bacterium or a blue whale.

Organisation of Life

Your body is like a perfectly organised factory with different levels of complexity. Cells are the smallest living units - imagine them as tiny workers doing specific jobs.

When similar cells team up, they form tissues (like muscle tissue). Different tissues combine to create organs (like your heart), and organs work together in organ systems (like your circulatory system). Finally, all these systems make up an organism - you!

Key tip: Remember the order from smallest to largest: Cell → Tissue → Organ → Organ System → Organism. This hierarchy appears in loads of exam questions!

Biological Reactions

Two massive chemical reactions keep life ticking along, and they're basically opposites of each other. Respiration happens inside your cells right now, releasing energy from glucose so you can move, think, and stay alive.

Aerobic respiration uses oxygen and creates carbon dioxide and water as waste products. When you're exercising hard and run out of oxygen, anaerobic respiration kicks in, producing lactic acid (that burning feeling in your muscles).

Photosynthesis is what plants do to make their own food using sunlight. It's the reverse of respiration - plants take in carbon dioxide and water to produce glucose and oxygen.

Remember this: Respiration releases energy, photosynthesis stores energy. They're like opposite sides of the same coin!

Classification

Scientists love organising things, and the Linnaean system is how they sort all living things into groups. Think of it like a filing system that gets more specific as you go down.

It starts broad with Kingdom (like animals or plants), then narrows down through Phylum, Class, Order, Family, and Genus until you reach Species - the most specific group.

Here's a memory trick: "King Philip Came Over For Good Soup" helps you remember the order from largest to smallest group.

Exam hack: You're likely to get questions asking you to put these categories in order, so practise this sequence until it's automatic!

Human Digestive System

Your digestive system is basically a 9-metre-long tube that breaks down food and absorbs nutrients. Food travels from your mouth down the oesophagus into your stomach, where acid begins breaking it down.

The liver and pancreas are your chemical factories, producing enzymes and bile to help digest fats and proteins. The gallbladder stores bile until it's needed.

Most nutrient absorption happens in your small intestine, whilst the large intestine removes water and forms waste. The journey ends at the rectum where waste exits your body.

Visual learner? Try tracing the path of a sandwich through your digestive system - it makes the whole process much clearer!

Parts of a Microscope

Microscopes are your window into the invisible world of cells. The eyepiece lens is where you look, whilst objective lenses on the nose piece provide different magnification levels.

The stage holds your specimen in place with clips, and the mirror reflects light up through your sample. Getting a clear image is all about the focus controls.

Use coarse focus first to get roughly the right distance, then switch to fine focus for crystal-clear images. Start with the lowest magnification and work your way up.

Lab success tip: Always start with the lowest power objective lens - it's much easier to find your specimen this way, and you're less likely to damage the slide!

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Biology

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190

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29 Dec 2025

•

6 pages

Introduction to Biology: Understanding the Basics

evie

@e777

Biology is all about understanding how life works, from the tiniest cells in your body to entire ecosystems. This summary covers the fundamental concepts you'll need to master - from how your body is organised to the chemical reactions keeping... Show more

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General Biology

Think of biology as the ultimate instruction manual for life itself. Every living thing follows the same basic rules, whether it's a bacterium or a blue whale.

Sign up to see the contentIt's free!

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Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Organisation of Life

Your body is like a perfectly organised factory with different levels of complexity. Cells are the smallest living units - imagine them as tiny workers doing specific jobs.

Key tip: Remember the order from smallest to largest: Cell → Tissue → Organ → Organ System → Organism. This hierarchy appears in loads of exam questions!

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Biological Reactions

Photosynthesis is what plants do to make their own food using sunlight. It's the reverse of respiration - plants take in carbon dioxide and water to produce glucose and oxygen.

Remember this: Respiration releases energy, photosynthesis stores energy. They're like opposite sides of the same coin!

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Classification

Scientists love organising things, and the Linnaean system is how they sort all living things into groups. Think of it like a filing system that gets more specific as you go down.

It starts broad with Kingdom (like animals or plants), then narrows down through Phylum, Class, Order, Family, and Genus until you reach Species - the most specific group.

Here's a memory trick: "King Philip Came Over For Good Soup" helps you remember the order from largest to smallest group.

Exam hack: You're likely to get questions asking you to put these categories in order, so practise this sequence until it's automatic!

Sign up to see the contentIt's free!

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Improve your grades

Join milions of students

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Human Digestive System

The liver and pancreas are your chemical factories, producing enzymes and bile to help digest fats and proteins. The gallbladder stores bile until it's needed.

Most nutrient absorption happens in your small intestine, whilst the large intestine removes water and forms waste. The journey ends at the rectum where waste exits your body.

Visual learner? Try tracing the path of a sandwich through your digestive system - it makes the whole process much clearer!

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Parts of a Microscope

Microscopes are your window into the invisible world of cells. The eyepiece lens is where you look, whilst objective lenses on the nose piece provide different magnification levels.

The stage holds your specimen in place with clips, and the mirror reflects light up through your sample. Getting a clear image is all about the focus controls.

Use coarse focus first to get roughly the right distance, then switch to fine focus for crystal-clear images. Start with the lowest magnification and work your way up.

Lab success tip: Always start with the lowest power objective lens - it's much easier to find your specimen this way, and you're less likely to damage the slide!