Variation, genes, environment, interspecific, intraspecific. Biology 2 17/11/2018 Variation LO: What is variation and what are its causes? All Most Some Be able to describe how variations in species occur. Be able to describe the difference between environmental and inherited variation. Be able to define the term ‘variation’. Key words Variation, genes, environment, interspecific, intraspecific.

Can you use standard English to share your opinion with the class? BLP objective Literacy objective Imagining Using your imagination to put yourself in new experiences or explore possibilities. What if? Reasoning Using logic and rational skills to work things out methodically – constructing good arguments. Can you use standard English to share your opinion with the class? Can you write your answers using standard English, scientific keywords and taking care of spellings and punctuation? 17/11/2018

Starter Activity What do you think the word “characteristic” means? Have a look at the person next to you. Can you identify some of their characteristics? Are they the same as yours or different?

Characteristics A characteristic is a feature of an organism. It can be something we can see (like hair colour) or something we can’t see (like blood group). All humans have different combinations of characteristics, meaning we all look different. This difference in our characteristics is called variation.

What characteristics? Students shown two pictures of Mr Men and asked to identify their characteristics. i.e. Mr Sneeze has blue skin, long legs, red nose etc. Assess understanding of the term characteristic.

What if they had a child? Students shown potential parents and asked to hold up their “child”. Ask students how they know that is their child – expect them to say “they have the same hair as their mother” etc. Highlight that these are inherited characteristics.

What if they had a child? Students shown another set of potential parents and asked to hold up their “child”. This time, ask which characteristics they have inherited from each parent. Encourage students to use appropriate terms.

Who are her parents? Students shown a child and asked who their parents are – hold up in pairs. Again discuss how they came to this conclusion.

Who are her parents? Students shown a child and asked who their parents are – hold up in pairs. Again discuss how they came to this conclusion.

What if they had a child? Students shown the parents for whom there is not a child in their set of cards. Ask them to discuss in pairs what they think their child would look like. Take answers as a class – highlight that they come up with many different combinations, all of which are possible. This highlights why we look different from our siblings – we inherit different combinations of characteristics (link back to variation). N.B. With higher ability class this could lead on to a discussion about dominant and recessive characteristics.

Find the different variations of species in the paragraph, and highlight to show what caused the variation On a visit to the zoo, a student saw lots of different types of big cat. In the pride of lions the males had a mane, but the females didn't. There was one lion with big scar on its face. Some of the lions were a little overweight. All the tigers had stripes, whilst the leopards had spots. Some of the leopards were larger than others. Key Inherited – Characteristics caused by genes found in the nucleus of all cells. Can be passed on from parents to offspring. Environmental – Characteristics caused by influences in the surroundings. Cannot be passed on from parents to offspring. Both – Some characteristics can be influences by both genes and the environment. Highlight these in a third colour.

Inherited Characteristics These are features that we get passed down to us from our parents. They are coded for by genes – little bits of DNA in our cells’ nuclei. We get half of our genes from our mother and half from our father because the nuclei of their sex cells fuses together in fertilisation.

Are all of our characteristics inherited?

Environmental Characteristics Some of our features are determined by how we live and the choices we make, for example what we eat and where we live. These are environmental characteristics Some characteristics can be both, for example height and weight.

Types of Variation There are two types of differences here. What do you think they are?

Types of Variation Interspecific variation – Variation between species. Intraspecific variation – Variation within species.

Variation in Humans Use you red, amber and green cards to categories each of the follow variations which can occur in humans.

Genetics, environment, or both? Having a scar from an injury Having a scar where a tattoo has been removed   Having red hair Being tallest in the class Being thinnest in the class Suffering from cystic fibrosis Suffering from scurvy Having lung cancer

Genetics, environment, or both? Having a scar from an injury Having a scar where a tattoo has been removed   Having red hair Being tallest in the class Being thinnest in the class Suffering from cystic fibrosis Suffering from scurvy Having lung cancer

Genetics, environment, or both?  Having red hair Having a scar where a tattoo has been removed   Having red hair Being tallest in the class Being thinnest in the class Suffering from cystic fibrosis Suffering from scurvy Having lung cancer

Genetics, environment, or both?  Having red hair (it depends!) Having a scar where a tattoo has been removed   Having red hair Being tallest in the class Being thinnest in the class Suffering from cystic fibrosis Suffering from scurvy Having lung cancer

Genetics, environment, or both? Being tallest in the class Having a scar where a tattoo has been removed   Having red hair Being thinnest in the class Suffering from cystic fibrosis Suffering from scurvy Having lung cancer

Genetics, environment, or both? Being tallest in the class Having a scar where a tattoo has been removed   Having red hair Being thinnest in the class Suffering from cystic fibrosis Suffering from scurvy Having lung cancer

Genetics, environment, or both? Being thinnest in the class   Suffering from cystic fibrosis Suffering from scurvy Having lung cancer

Genetics, environment, or both? Being thinnest in the class   Suffering from cystic fibrosis Suffering from scurvy Having lung cancer

Genetics, environment, or both? Having green eyes   Suffering from scurvy Having lung cancer

Genetics, environment, or both? Having green eyes   Suffering from scurvy Having lung cancer

Genetics, environment, or both? Having a tattoo   Having lung cancer

Genetics, environment, or both? Having a tattoo   Having lung cancer

Genetics, environment, or both? Having lung cancer   Having lung cancer

Genetics, environment, or both? Having lung cancer   Having lung cancer

Odd One Out Hair Colour Weight Blood Group

Odd One Out Sporting ability Scars Accent

Key Points This lesson I have learnt: Inherited variations are characteristics inherited from parents   Environmental variations are variations caused by the surroundings   Many variations are affected by both inherited and environmental factors.