Genetics

• Biologie
• Basisschool
• Groep 7

Genetics

Can you roll your tongue?

Yes

no

Do you have dimples?

Yes

no

Are you righthanded?

Yes

No

Do you cross your left thumb over your right when you clasp your hand together?

Yes

No

Today I will learn ...

... the meaning of hereditary.

... how traits can be passed down throught generations.

... the meaning of genotype and phenotype.
... the difference between dominant and recessive.
... how to read a family pedigree.

What is the meaning of hereditary?

Hereditary

The passing of traits from parents  to their offspring.

Eye colour is an example of a hereditary trait.

1. yes
2. no

Jamie, 8

Jamie is a 8 year old boy. He was born with thick curly hair, but both of his parents have straight hair. He has 3 other siblings and they also have straight hair. How is this possible?

If Jamie gets another sibling. What is the chance for it also having curly hair?

1. 10%
2. 20%
3. 25%
4. 50%

Dominant and recessive genes

Dominant Genes: These are stronger and tend to show up in the phenotype, even if there’s only one copy. For example, if brown eyes are dominant, you only need one brown-eye allele to have brown eyes.

Recessive Genes: These are weaker and usually only show up if you have two copies of the allele. For example, blue eyes are recessive, so you’d need two blue-eye alleles to have blue eyes.

Allele is a version of a gene.

Genotype:

This is the set of genes that an organism has inside it, like a code or recipe that determines certain traits.

It's the code of the gene inside.

Phenotype:

This is what we see on the outside, like eye color, height, or hair color. It’s how the genotype shows up in real life.

What we see from the outside.

Genotype is the gene that we see on the outside.

1. yes
2. no

Which gene will show if you have two copies of the allele?

1. Dominant
2. Recessive

A family pedigree

A family pedigree

•  circles and squares
• Marriage lines
• Offsrping lines
• Affected and unaffected
• Generations

Why is a family pedigree useful to us?

05:39

What will the trait letters be of 4, 7 and 9?
Write like this:
4=... 7=... 9=...

Today I learnt ...

... the meaning of hereditary.

... how traits can be passed down throught generations.

... the meaning of genotype and phenotype.
... the difference between dominant and recessive.

... how to read a family pedigree.

ASSIGNMENT

Do you have special traits in you family? Make a family pedigree of that trait. Try to make it as big as possible.