VariationLearning Intentions:

• Variation within a population makes it possible for a population to evolve over time in response to changing environmental conditions.

• State that an adaptation is an inherited characteristic that makes an organism well suited to survival in its environment.

• State that variation can occur within a population caused by meiosis, sexual reproduction and mutation.

• Give examples of variation within a population.• State that variation leads to evolution over time in

response to changing environmental conditions.

Starter…

On a show me board list all the differences between animals naturally found in Scotland and animals found near the equator.

Variation

Learning Intentions:

• State that variation can occur within a population caused by meiosis, sexual reproduction and mutation.

• State that variation leads to evolution over time in response to changing environmental conditions.

Success Criteria:

• Describe the differences in populations• Investigate variation in humans and plants

VariationVariation is the differences found throughout a species.

It is caused by mutations, meiosis and sexual reproduction.

Mutations cause differences in individuals.

If these mutations are advantageous or neutral to the organism, it will survive and reproduce, passing its genes (and the difference) onto the next generation.

Variation leads to evolution over time in response to changing environmental conditions.

Variation in Humans1. Carry out a survey of tongue rolling, eye colour and foot length

in your class.

2. Discuss what kind of table you could use to record your results.

3. Draw 3 suitable tables to record your result.

4. Collect data from your class.

5. Select one characteristic and draw a suitable graph.

6. Identify the characteristic as continuous or discrete variation.

7. Describe what your results and graph show.

8. Describe how your survey could be improved.

NumeracyUnit 2 recap

Variation in plants1. Complete a survey on plant height, petal colour and leaf number or

shape.

2. Discuss what kind of table you could use to record your results.

3. Draw 3 suitable tables to record your result.

4. Collect data from your class.

5. Select one area and draw a suitable graph.

6. Identify the characteristic as continuous or discrete variation.

7. Describe what your results and graph show.

8. Describe how your survey could be improved.

NumeracyUnit 2 recap

Continuous Variation

• A characteristic that gradually changes over a range of values.

• E.g, height, weight, foot length.

Unit 2 recap

Discrete Variation

• A characteristic with only a limited number of possible values.

• E.g. blood group, ear lobes (attached or unattached) or tongue rolling ability.

Unit 2 recap

Variation

Learning Intentions:

• State that variation can occur within a population caused by meiosis, sexual reproduction and mutation.

• State that variation leads to evolution over time in response to changing environmental conditions.

Success Criteria:

• Describe the differences in populations• Investigate variation in humans and plants

Starter:

On a show me board write your ideas about these questions:

1.Why do sheep survive here in Scotland?

2.Why would you not find the same sheep living in South Africa?

VariationLearning Intentions:

• Variation within a population makes it possible for a population to evolve over time in response to changing environmental conditions.

• State that variation leads to evolution over time in response to changing environmental conditions.

Success Criteria:

• Explain what an adaptations is and why it helps organisms survive in the habitat in which they live

There are three major types of environment. What are they?

land freshwater marine

How do organisms survive in such different environments?

Different types of environment

What does the word

adaptationadaptation mean to you?

Adaptations

• An adaptation is an inherited characteristic that makes an organism well suited to survival in its environment or niche – role within the environment.

• If an organism can survive long enough to reproduce they are able to pass their DNA (with these characteristics) onto the next generation.

Look at how quickly the chameleon in this clip can adapt!http://www.chameleonshops.com/super-chameleon/

What adaptations have occurred in each of these pictures?

• An adaptation can be structural or behavioural. Both can aid the organism’s survival.

Structural Adaptation

A desert is a habitat where the conditions are extremely dry and the soil lacks water.

A normal land plant e.g. an oak tree would be unable to survive in the desert.

A desert plant such as the cactus is able to survive in the desert because it possesses certain adaptations:

Structural adaptations

• Stem is fleshy and stores water in succulent tissues.

• Water loss from the stem is kept to a minimum by thick, waxy cuticle which coats

its outer surfaces.

• Leaves are reduced to spines to reduce water loss and protect the plant from herbivores.

Structural adaptations

Roots:

• Some cacti have very long roots for reaching supplies of subterranean water.

• Others possess extensive systems of superficial roots which grow parallel to the

soil surface. These enable the plant to absorbmaximum quantities of water when it rains.

Cactus and adaptation clips

• http://www.bbc.co.uk/learningzone/clips/adaptation-of-plants-and-animals/5304.html

• http://www.bbc.co.uk/learningzone/clips/how-cacti-survive-without-water/66.html

Adaptations of a Desert Adaptations of a Desert PlantPlant

Your task… Your task… Using the information you have just learnt produce a summary diagram to show the structural adaptations of a desert plant.

How am I adapted to live in the desert?

Plant Adaptations

• Bee pollinated plants have adapted to have petal colours related to bee vision.

Bumblebee vision.

• Bumblebees have two eyes and also detect light with 3 ocelli or “primative eyes”.

Bumblebee vision

• Bumblebees cannot see the colour red but can see UV light that we cannot.

Plant adaptations

• Plants have adapted to have petal colours which bumblebees can see and are attracted to. This means they are pollinated and pass their genes onto the next generation.But, bumblebees do sometimes visit red flowers…

- can you think of a reason why?

• Red flowers visited by bumblebees may have emitted attractive smells or have UV patterns we cannot see.

VariationLearning Intentions:

• Variation within a population makes it possible for a population to evolve over time in response to changing environmental conditions.

• State that variation leads to evolution over time in response to changing environmental conditions.

Success Criteria:

• Explain what an adaptations is and why it helps organisms survive in the habitat in which they live