Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring. Through heredity, variations between individuals can accumulate and cause species to evolve by natural selection. Genes are the basic unit of heredity. This means that genes determine what traits are passed down from a mother and father to their child. Eye colour, height, and hair colour are some examples of the traits that are controlled by genes.


Recessive traits
In any one family, some children might inherit a recessive gene, or all of them, or none of them; even if both of their parents are carriers the chances are still only one in four. Depending on the genetic match of the parents, the lists below show the likely characteristics that will be inherited by their children.

Dominant Traits                  Recessive traits

Brown eyes                               Green, grey, hazel or blue eyes

Dark hair                                  Blonde or red hair

Normal vision                         Colour blindness

Full lips                                     Thin lips

Freckles                                    No freckles

The Weasley Factor

Though medical geneticists are generally uninterested in what children look like, they have worked out one gene code for appearance: the MC1R gene produces red hair and pale skin that's likely to burn because it doesn't have photo-protective melanin. Due to the rarity of this gene, some experts predict that natural red-heads will be no more red heads as early as 2060. Natural blondes could also be on the wane in the UK where only two per cent of the population are naturally blonde.

The language of the genes
Scientists at the Centre for Human Genetics in Oxford have identified the first gene known to be involved in the development of speech and language. It is believed this will lead to improved diagnosis of language disorders and other conditions, like autism. It had always been assumed there was a genetic basis to speech and language as it's acquired almost instinctively by children. The Oxford team got their breakthrough by studying three generations of a family affected by a rare language condition. Now they're working on tracking down the gene which predisposes children to dyslexia.

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How big will they grow?
Everyone wants to know how tall their son or daughter will be, though most parents are more concerned about boys' height. There are many ways of predicting height - one way uses a complicated formula involving the combined heights of the parents. This prediction has a 68 per cent chance of being within two inches of their adult height. To try this method, visit Pediatrics.About and write 'height prediction' in the search box. Another way is to simply double the height your child was aged two.

What makes you YOU: Books about Genes and Identity for Children

gens book for kids

Me The One and Only Me: A Book About Genes by Ariana Killoran

Join Poppy on her journey into the fascinating world of her genetics. Learn how Poppy’s genes created her red hair and blue eyes — and trace these traits through her family tree.

DNA book

The DNA Book: Discover what makes you YOU by DK

This book gives children an in-depth look at DNA and its role in all living things--from why we have different-coloured eyes to why we age.

makes me a me

What Makes Me a Me? By Ben Faulks and David Tazzyman

A funny and thought-provoking look at what makes us us, from Ben Faulks (known as Mr Bloom from CBeebies) and David Tazzyman (bestselling illustrator of You Can't Take an Elephant on the Bus). Guaranteed to feed the imagination, this celebration of being who we are is perfect for inquisitive (and inventive!) little minds.


Grow: Secrets of Our DNA by Nicola Davies and Illustrated by Emily Sutton

A fabulously illustrated introduction to the concept and mysteries of DNA for young readers. All living things grow – every plant and every animal, and of course human beings this book explains how things grow with scientific concepts told in an engaging and highly digestible way for kids.

genes for kids

You Share Genes with Me by Ariana Killoran

Our DNA connects us all, big and small! You Share Genes with Me offers the very youngest readers a playful introduction to genetics. Through simple rhyme and whimsical illustrations, children and older readers alike will discover what they share in common with a monkey, a fish, a fruit fly, even each other.


Genetics for Smart Kids: A Little Scientist's Guide to Cells, DNA, Genes, and More! by Carlo Pazos

Future Geniuses are a collection of books that through simple text and fun illustrations explain science to young children.Written by author and scientist Carlos Pazos, this books makes the subject of genetics approachable and easy to understand for even the smallest scientists with Little Doctor Valentina the dog.