Posts Tagged ‘allele’

Chromosomes, genes, alleles and mutations

Tuesday, April 5th, 2011

sickle cell anemia by udt007us on flickr

We are about to embark on the last topic of the year!  It’s a great topic – and an important one – all to do with GENETICS.  Here is the syllabus guide: Topic 4 – Syllabus outline

In this first section we need to know what eukaryotic chromosomes are made of, and be able to define the terms gene, allele, genome and gene mutation.  We’ll learn about the disease sickle-cell anemia – how it is caused by substitution of a single base in the gene for making haemoglobin.  This will be a good review of transcription and translation [remember them?] as well.  Here is Mr Taylor’s presentation covering these points.

Click here for an excellent blog post that will help you understand how all this connects together.


Monday, October 11th, 2010

Genetics by Here's Kate on flickr

The system of inheritance is actually very logical.  We will learn what alleles are and how they combine to form an individual’s characteristics.  We will look at simple monohybrid crosses, involving things like eye colour, tongue-rolling and earlobes.  Then we will expand into multiple alleles and co-dominance (blood groups).  Next we’ll understand why equal numbers of boys and girls are born in the world and look at examples of sex-linked inheritance.  We will be simplifying the concepts – in reality many human characteristics are controlled by several genes on different chromosomes – so the real picture is more complex.  And we’ll finish up with a discussion of how much of our variation is down to our genes, and how much is due to environment.

There will be some new vocabulary to learn (Genetics terms), then lots and lots of problems to solve.  Try these ones for starters:  Genetics Questions and Simple Genetics problems

Here are some questions on co-dominance, multiple alleles and sex-linkage. Genetics Problems

This document contains a list of great websites with plenty more genetics practice. Online genetics problems