Free Science Video – What is DNA?

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Some of your students may want to find out more about how DNA works. This video:

explains it in a clear way that they will understand.  

DNA explained The video uses clear graphics to explain DNA. It starts by looking at its molecular structure, then goes on to how minute differences in the DNA leads to variation and finishes by looking at some ways that we can manipulate DNA, such as selective breeding and genetic engineering.

We learn that DNA is the instruction manual for how to build life and see how the base pairs are arranged in the DNA molecule and how the two strands that make up molecule curl round each other to form the double helix. This graphic is very useful to show students more detail about the structure of DNA.

Chromosomes and genes are then introduced and the link with proteins and their roles in organisms. This allows students to understand the link between the order of bases in the DNA and the characteristics of an organism.

Even though this is not mentioned specifically at KS3, your students may well ask the question “how does DNA code for our characteristics?” and this video answers it for them in a simple way.

Some questions you could ask your students after they have watched the video are:

What is the difference between a gene and a chromosome? A gene is a small section of DNA that codes for a single protein. A chromosome is a package of DNA. Humans have 23 pairs of chromosomes.

How different is your DNA from the person sitting next to you? Why does this mean you look different? 0.1%. This means that the genes in this percentage code for proteins that give humans genetic variation (of course, environmental variation also exists and also explains why people vary).

We have genes in common with all living organisms on Earth, even bacteria. How is this evidence for evolution? Because it proves that all life evolved from one common ancestor.

What are some uses of genetic engineering? Plants that can resist drought or disease and bacteria that can mass-produce hormones such as insulin.

Your students can find out more about what types of characteristics are inherited by completing the  ‘Homework Activity: Famous Family Inheritance’ activity at home.

 

What is Smart Science?

Written for the new 2014 Science Curriculum, Smart Science provides a flexible scheme of work that can be used to deliver either a 2 or 3 year Key Stage 3. If you’d like to see more, then check out these free Smart Science resources.

Exploring DNA this term with your students? Here are some more free resources: