Classification and Heredity

At the end of this lesson you should be able to: 1. Discuss the diversity of organisms 2. Define the term species 3. Distinguish between inherited and acquired variation 4. Give examples of inherited and acquired variations

Variation means that there are differences between members of the same species i.e. a population Think of all the variations within your class even though you are all human

A group of organisms capable of interbreeding and producing fertile offspring. Humans Cats Dogs Oak Trees Ash Trees

Liger = male lion + female tiger

Males are sterile but females are fertile – so not a new species Tigon = male tiger + female lion

What is meant by variation? Give the definition for species Why is a liger not a new species?

1. Inherited Variations 2. Acquired Variations

These are variations that you get from genes inherited from your parents They can be passed onto the next generation Hair Colour Eye Colour Face shape Tallness You inherit different traits from each parent

These are not inherited. You are not born with these types of variations. These are learned or picked up through your lifetime. These variations are the influence of your environment They are not passed on to the next generation Examples: Which language do you speak? Which sport do you play?

We all have the same the inherited characteristics. but We all have different versions of the same characteristics called traits. CharacteristicTraits Hair ColourRed, Blond, Black

1. What are the two types of inheritance? 2. Your hair colour is black - is this an example of acquired or inherited variation? 3. You can play the piano - is this an example of acquired or inherited variation?

Can you ………. 1. Discuss the diversity of organisms 2. Define the term species 3. Distinguish between inherited and acquired variation 4. Give examples of inherited and acquired variations

Genetics – the study of heredity

At the end of this lesson you should be able to 1. Define the term heredity 2. Define the term gene 3. Outline the role of a gene 4. Define the term gene expression 5. Know the structure of a chromosome

Heredity is the passing on of features from parents to offspring by means of genes Also called Genetic Inheritance

A gene is length of DNA that codes for a specific protein It is the unit of inheritance It is found on a chromosome It contains instructions to make a particular protein It directly influences the characteristics of an organism

Characteristics are controlled by genes. For example everyone has genes which determines hair colour. But not everyone has the same version of those genes. So there is more than one type of gene for hair colour that you could have.

Not all genes are expressed Genes produces characteristics or traits that are inherited Eg: Gene for Tallness Organism is small – Why? Maybe due to poor nutrition

Characteristics = heredity + environment

Heredity is the passing on of _________ from parents to ______________ by means of ______ A gene is the unit __________________. They are found on a _________________. They contain ________________ to make a particular _______________. Gene expression is the way in which ____________ ________________ in a gene is decoded

Chromosomes contain a number of genes

Chromosomes are made up of 60% protein 40% DNA Genes are arranged along the DNA of the chromosome

Large sections of the chromosome do not contain genes This DNA is called Non Coding DNA It’s function is not yet clear

Thread like structures Contains DNA Contains Protein Contains Genetic Information Occur in pairs Found in the nucleus of all cells

Can you ……………. 1. Define the term heredity 2. Define the term gene 3. Outline the role of a gene 4. Define the term gene expression 5. Know the structure of a chromosome