3 SCIENCE Chpt 4 Reproducion and inheritance 2

What is variation?

Differences in characteristics in organisms from the same group.

What are the two types of variation?

Genetic (inherited) and non-inherited (acquired) variations.

Inherited characteristics (Examples)

Hair colour, blood type, and the ability to roll your tongue.

Acquired characteristics (Examples)

The ability to read, the ability to ride a bike, and your accent.

Dominant trait

A trait that shows even if only one parent passes the gene for it.

Recessive trait

A trait that only shows itself if both parents pass the gene for it.

Genotype

The combination of genes a person inherits, represented by letters (e.g., Bb).

Phenotype

The way genes show themselves physically, represented by words (e.g., Brown eyes).

Genetic crosses letter representation

Dominant traits use a capital letter (e.g., B) and recessive traits use a lower case letter (e.g., b).

What does a 'Bb' genotype indicate?

You will have brown eyes and be a carrier of blue eyes.

What does a 'bb' genotype indicate?

You will have blue eyes.

what does a 'BB' genotype indicate?

you will have brown eyes