Genetics

Inheritable and Non-inheritable characteristics

some characteristics are passed on from parents to children – these are called inheritable…

these characteristics may in turn be passed on to the following generation(s)…

Inheritable and Non-inheritable characteristics

other characteristics are independent of parentage – these are called non-inheritable…

these characteristics will not be passed on to the following generation(s)…we hope!

Inheritable characteristics are received from parents…

father mother

Check out some of your own inheritable characteristics…

Arm fold preference “Hitchhiker’s thumb” Pinkie finger alignment Ear lobe attachment

Check out your own…Arm fold preference: fold your

arms - Do you fold right-over-left or left-over-right?

Check out your own“Hitchhiker’s thumb”: extend your

thumb – ? Is it straight or curved?

Check out your own … Pinkie fingers: place them side by side –

? Are they straight or curved away from each other?

Check out own … Ear lobes: look at your ear in a

mirror – ? Is it directly attached or

separated ?

Other inheritable characteristics include:

eye colour freckles

blood type

haemophilia

cystic fibrosis

Some non-inheritable characteristics:

Athletic ability Artistic ability Accent

For each inheritable characteristic, a human has two genes – one passed on by the father’s sperm cell, the other by the mother’s egg cell

one gene for eye colour

one gene for eye colour

two genes for

eye colour

CELL Nucleus

©news.bbc.co.uk

These are Chromosomes the genes are on the chromosomes

© 2005 Chugoku Rosai Hospital

• DNA is what makes a chromosome• A part of the DNA that controls a

characteristic is called a GENES• The gene is the code for any one inherited

character – e.g. eye colour

Genetics

© 2005 Chugoku Rosai Hospital

• the long DNA molecule is so twisted and coiled so that it takes up tiny little space…A Double Helix

• each twisted coil of DNA, containing many genes, makes one chromosome…

• small molecules of protein help keep the chromosome in shape

• DNA stands for deoxyribonucleic acid

• It is twisted into a double helix and contains all the codes to build a body

• the code contains instructions for every structure and function the body will ever need

Four Amino Acids in DNA

• Cytosine • Guanine• Thiamine• Adenine

• the code in DNA is different in every human being…(except for ?????)

• Each individual’s unique code is called their DNA fingerprint

• because of this, DNA is used in

• crime scene investigation

• parental disputes

Solved with DNA.

• the code in DNA is different in every human being…except for ?????

IDENTICAL TWINScan you explain why

Summary

• DNA• Inheritance• Gene• Chromosome

H/W

• P89• Q 5-8