Genetics Ms Atkinson 2012

Genetics is the study of heredity

Inherited characteristics such as eye and hair colour are controlled by genes Non-inherited characteristics, such as playing a guitar or riding a bike, must be learned

Inherited Acquired

Inheritable characteristics are received from parents… OB35 understand that humans have inheritable and non-inheritable characteristics Inheritable characteristics are received from parents… father mother www.juniorscience.ie

Check out some of your own inheritable characteristics… OB35 understand that humans have inheritable and non-inheritable characteristics Check out some of your own inheritable characteristics… Arm fold preference “Hitchhiker’s thumb” Pinkie finger alignment Ear lobe attachment www.juniorscience.ie

OB35 understand that humans have inheritable and non-inheritable characteristics Check out your own… Arm fold preference: fold your arms - ?Do you fold right-over-left or left-over-right? www.juniorscience.ie

? Is it straight or curved? OB35 understand that humans have inheritable and non-inheritable characteristics Check out your own “Hitchhiker’s thumb”: extend your thumb – ? Is it straight or curved? www.juniorscience.ie

? Are they straight or curved away from each other? OB35 understand that humans have inheritable and non-inheritable characteristics Check out your own … Pinkie fingers: place them side by side – ? Are they straight or curved away from each other? www.juniorscience.ie

? Is it directly attached or separated ? OB35 understand that humans have inheritable and non-inheritable characteristics Check out own … Ear lobes: look at your ear in a mirror – ? Is it directly attached or separated ? www.juniorscience.ie

Other inheritable characteristics include: OB35 understand that humans have inheritable and non-inheritable characteristics Other inheritable characteristics include: eye colour freckles blood type haemophilia cystic fibrosis If you are connected to the internet, some of the images will link you to a source of information www.juniorscience.ie

Some non-inheritable characteristics: Athletic ability OB35 understand that humans have inheritable and non-inheritable characteristics Some non-inheritable characteristics: Athletic ability Artistic ability Accent www.juniorscience.ie

two genes for eye colour OB35 understand that inheritable characteristics are controlled by genes 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 two genes for eye colour one gene for eye colour one gene for eye colour www.juniorscience.ie

Genes are found on chromosomes In a human there are 23 pairs of chromosomes (i.e. 46 chromosomes) Chromosomes are located in the nucleus of a cell Chromosomes are made of DNA and protein

23 pairs of chromosomes, which are located in the nucleus ©news.bbc.co.uk www.juniorscience.ie

DNA stands for deoxyribonucleic acid

These chromosomes combine to make a zygote Every zygote is a 1 in 64,000,000,000,000 combination of chromosomes

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 www.juniorscience.ie

the code in DNA is different in every human being…except for ????? can you explain why www.juniorscience.ie

How are twins different?

Genetics and prediction!

Groups of Three One recorder. Two labradors.

YOU ARE NOW A LABRADOR You are given two cards. On the cards are your GENOTYPE. Each card has one ALLELE (type of gene) on it. This particular allele is for COAT COLOUR. If you are a Black Lab : G G or G g If you are a Chocolate Lab: g g

Sometimes a compromise is reached in genetics or sometimes both are expressed!!

This is called co-dominance and incomplete dominance

Incomplete dominance– a intermediate trait is expressed (black and white = grey)

Co - dominance Both traits are expressed!

[2007] Where is DNA located in cells? Name a second substance associated with DNA.

[2008] At certain stages in the life of a cell thread-like structures that contain genes can be seen in the nucleus. What are these thread-like structures called? Genes are located on these thread-like structures. Give a role that genes play in life processes.

[2006] Eye colour, hair texture and many other human characteristics are controlled by genes. Name the structures in the nuclei of our cells where genes are located. Name the substance that genes are made of.