science 3.6 variation

8/7/2019 sciEnce 3.6 variation

1/14

I MISS SCIENCE!!!


2/14

Previous lesson

What is genetic research?

What are the contribution of geneticresearch?


3/14

Eliciting students ideas

Look at your friends next to you, does their

skin colour height, weight, same with each

other?

Check also their

Blood group Ear lobes

Tongue rolling

Left heanded


4/14

Today we are going to learn

about

3.6Analysing variation among living things


5/14

Learning outcome

At the end of the lesson, a student is able to

1. State what is variation is

2. Lists variation in humans3. Classify variation into continuous and

discontinuous variation

4. Compare and contrast continuous anddiscontinuous variation

5. Explain the importance of variation


6/14

What is variation?

Variation is differences between individuals

the same species.


7/14

Lists the variation in human

Height

Weight

Hair colour Skin colour

Eye colour

Intellgent


8/14

How many types of variation in

human?Variation in human

Discontinuous variation:Variation which shows a

clear-cut difference

Example:

Ability to roll the tongue,presence or absence of ear lobes,

right handed or left handed,straight or curly hair and blood

group

Continuous variationVariation that does not

showobvious differences

Example:

Weight,Height, skincolour, hair colour and

intelligent


9/14

What are the factors which

cause variation?

Genetic factors- genes inheritedfrom the parents .

Example : blood group, eye colour


10/14

Environmental factor

This type of variation can change.

Example :

Weight of o person affected by the type andquantity of food he eats

The skin of a people gets darker by exposureto sunlight

Ability to speak certain language.


11/14

Similarities and differences between continuous

and discontinuous variation

Continuous variation

Traits that have clear-cut differences withoutany range in between

Similarity : types of variation which shows differences within a species

Discontinuous variation

Nature ofdifferences

Can be inheritedno

A small degree of

variation over acontinuous range

Yes

Differences


12/14

Example

Environmentsfactors

Can the changeshappen from time

to time?

Not affected byenvironment

No

Tongue rolling,blood group

Affected by

environmental

Yes

Height, Weight

Differences


13/14

What are the importance of

variation? Enable each individual to be different from

others.

Allows the formation of an individual withdifferent characteristic which is moreresistant to changes in the surroundings.

Allows cross-breeding among organisms toform new breeds.


14/14

Conclusion

Variation is differences between individuals

the same species.

Continuous variation:Variation that does notshow obvious differences

Discontinuous variation: When the

differences among individuals fall intodistinct categories

science 3.6 variation

Documents