Genetics Lesson 2 - Genes, genomes and alleles

Lesson 2 - Genes

by Jessica Tipping

​Genes

• ​DNA is inherited from parents

• DNA carries coded information in Genes.

• Genes are sections of DNA that codes for a polypeptide.

• 1 gene = 1 unit of genetic information

• Genes can be switched on/off

• DNA in all organisms is the same, the difference is the DNA sequence.

​Alleles

Allele: A different version of a gene.

• Alleles comes from a small difference in the DNA sequence.

Example; The single gene for eye colour has many alleles. One allele gives brown eyes, another blue eyes.

A normal organism has two alleles for each gene, one from each parent.

​Genomes

A genome is an organism's complete set of DNA, including all of its genes. Each genome contains all of the information needed to build and maintain that organism.

​Genomics

​Genome: All the genetic instructions in your DNA.

​Genomics

• The rate at which genomes can be sequenced has been doubling every four months or so. 

• With the advent of new analytical tools, biologists’  ability to generate genomic data will help reveal more about how genes work and how species are related. 

Multiple Choice

A segment of DNA that codes for a trait

• gene

• centromere

• chromosome

• chromatid

Open Ended

Where are genes found?

Open Ended

What do genes code for?

Multiple Choice

Genes are all switched on from birth.

• True

• False

Multiple Choice

A version or variation of a gene

• trait

• gene

• allele

• DNA

Multiple Choice

What is a genome?

• The complete genetic material present in a cell or organism

• A garden ornament 

• The sum of all cell material.