Genetics www.juniorscience.ie

1B5 Genetics inheritable and non-inheritable characteristics, chromosomes and genes www.juniorscience.ie

1B5 Genetics OB35 understand that humans have inheritable and non-inheritable characteristics, and that inheritable characteristics are controlled by genes OB36 recall that genes are located on chromosomes and that in a human there are 23 pairs of chromosomes, which are located in the nucleus OB37 recall that chromosomes are made of DNA and protein www.juniorscience.ie

OB35 understand that humans have inheritable and non-inheritable characteristics some characteristics are passed on from parents to children – these are called inheritable… other characteristics are independent of parentage – these are called non-inheritable… these characteristics may in turn be passed on to the following generation(s)… these characteristics will not be passed on to the following generation(s)… www.juniorscience.ie

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 your own … Ear lobe: 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: Height Shoe size OB35 understand that humans have inheritable and non-inheritable characteristics Some non-inheritable characteristics: Height Shoe size 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

chromosomes in the nucleus OB36 recall that genes are located on chromosomes which are located in the nucleus chromosomes in the nucleus www.juniorscience.ie

OB36 recall that genes are located on chromosomes which are located in the nucleus image from http://regentsprep.org/Regents/biology/units/heredity/dna.cfm www.juniorscience.ie

OB36 recall that in a human there are 23 pairs of chromosomes, which are located in the nucleus ©news.bbc.co.uk www.juniorscience.ie

OB37 recall that chromosomes are made of DNA and protein DNA stands for deoxyribonucleic acid it is a molecule built in a particular code the code contains instructions for every structure and function the body will ever need the DNA code for each separate structure or function is called a gene this makes it a very very long molecule…so how does it fit into a very tiny nucleus? www.juniorscience.ie

OB37 recall that chromosomes are made of DNA and protein © 2005 Chugoku Rosai Hospital the long DNA molecule is so twisted and coiled so that it takes up tiny little space… each twisted coil of DNA, containing many genes, makes one chromosome… small molecules of protein help keep the chromosome in shape www.juniorscience.ie

OB37 recall that chromosomes are made of DNA and protein 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

OB37 recall that chromosomes are made of DNA and protein the code in DNA is different in every human being…except for ????? IDENTICAL TWINS can you explain why www.juniorscience.ie

OB37 recall that chromosomes are made of DNA and protein How small is DNA? If you are connected to the internet, click on the image below to get an idea www.juniorscience.ie

Genetics OB35 understand that humans have inheritable and non-inheritable characteristics, and that inheritable characteristics are controlled by genes OB36 recall that genes are located on chromosomes and that in a human there are 23 pairs of chromosomes, which are located in the nucleus OB37 recall that chromosomes are made of DNA and protein www.juniorscience.ie