National 5 Biology

Here are some useful materials to help you enjoy learning Biology at National 5 Level.

The first section has more General links for the whole course and following that I have listed links to the specific Units in the National 5 Biology Course

General Course Information :

Some Revision Links
  • Revision - Oronsay  Fantastic Revision Resources/Quizzes for National 5 Biology from a teacher I guess who lives on Mull at Oronsay Guest House!
  • eChalk Learning Materials  Some of these interactive learning materials are very good - and some nice photographs of cells. You can preview the materials or pay to join the site for a year:

Unit 1 - Cell Biology

Key Area 1.1   Cell Structure


The Scale of Cells
Use the scale to zoom in and see the size of some human cells, an E.Coli bacteria and some viruses in comparison with eg a coffee bean or a grain of rice

A bit about Microscopes and working out sizes of cells / magnification etc.

Single Celled creatures

Paramecium diagram ___________________________________________

Key Area 1.2   Transport across Membranes

Video of Plasmolysis in an Onion Cell when its placed in a 15% salt solution
Can you explain why the onion cells are plasmolysing?
also see:

Experiment on Osmosis in Potatoes
Shows how to do the experiment. And there are some results at the end that you could use if you can't do the experiment yourself. Though you could try this experiment at home fairly easily.


Diffusion / Osmosis / Active Transport

Animation on Page 3 of this explanation about Kidneys:

Key Area 1.3  DNA and production of Proteins

All the chromosomes in a nucleus - 
Thanks to Dietzel65 for the photograph from wikimedia commons -
(extra explanation - too complicated for National 5 but might be of interest - Karyotype from a female human lymphocyte (46, XX). Chromosomes were hybridized with a probe for Alu sequences (green) and the rest was counterstained with TOPRO-3 (red stain). The green Alu sequence markers show chromosomes and chromosome bands rich in genes.)

Key Area 1.4 Proteins

Proteins and Enzymes
An Enzyme Experiment with Pineapples to Try at Home !

The effect of enzymes pineapples and why they are used in cooking
Using the enzyme in Pineapples in a Hospital for treatment
Catalase enzyme in Liver experiment - nice demo -

Key Area 1.5  Genetic Engineering

Information about Golden Rice - a genetically modified crop plant:

Key Area 1.6  Respiration

- use my Powerpoint here ....

Unit 2 - Multicellular Organisms

Key Area 2.1  Producing New Cells

Mitosis in Onion Root Tip Cells Mitotic Stages in Apical Meristem of Allium Root Tip (37385550196)
Thanks for great image from Berkshire Community College Bioscience Image Library / CC0 - click on it for more information

Zoomable photos of mitosis
Have a look at photographs of mitosis and you can even zoom in yourself on the root tip of an onion to see if you can spot the different stages of mitotic cell division :

Remember Mitosis - happens in your TOEsis - and all normal cells of your body.

Plant Cells in a Leaf Diagram
from :

Stem cells
Stem cells can be used for therapy -
eg growing new skin for this boy:

The first few pages here are relevant to National 5 Biology about stem cells but read on if you are interested:

in a plant

Meristem in a Broad Bean seedling experiment:

Key Area 2.2  Control and Communication

The "moro reflex" is a reflex action that you will find in a baby - why do you think babies do this?

Key Area 2.3  Reproduction

Parks of a Flower
Mature flower diagram

Diagram from LadyofHats, Public domain, via Wikimedia Commons

Key Area 2.4  Variation and Inheritance

My Monohybrid Cross Quiz

Nice video on here from BBC Bitesize:


Key Area 2.5 - Transport Systems - Plants

Plants - Xylem / Phloem - sugar / water etc

Key Area 2.6 - Transport Systems - Animals

The heart - animation

Key Area 2.7 - Absorption of Materials


Breathing Animation
This video shows how you can make a model of the lungs with the diaphgragm:

Gas exchange in Breathing - which gases are in inhaled and exhaled air?
You could make a pie chart ...

Unit 3 Life on Earth

Food Chains

Help Deadly 60's Steve find the food chain's deadliest predator :

Ecosystems - Habitat - Indicator Species
Lichens can be an indicator species with the finer lichens indicating pure air - here is a nice guide to the different types of liches
How to use Lichen as an indicator species:

An interesting short two minute video about photosynthesis :

To see bubbles given off when light lands on Elodea pondweed plant - this is a nice short video to show this happening -

Starch in Leaf Test Experiment
Excellent video of this experiment:

Very good re the T on a leaf and starch test - certainly from half way through:
Limiting Factors in Photosynthesis

The three limiting factors which we study are temperature, availability of carbon dioxide and light intensity. The Bitesize website has a good explanation of the types of questions involving graphs which you might come across :


The following is not in National 5 content -

How the Ear Works
An animated video about how the ear works - don't worry too much about the words used for the small bones in the ear hear as there are various names for them, but watch the animation :