telling the boys from the girls

In practical 1 this semester you will be setting up crosses with Drosophila melanogaster, aka the annoying fruit fly! So it is going to be pretty important for you to be able to tell the boys from the girls...

Here are some pictures to help you out:

This first pic is a diagram comparing the male and female fruit fly - the main things to note are

1. The female is bigger than the male
2. The male has a rounded abdomen
3. The female has a more pointed and elongated abdomen 
4. The dark banding on male abdomen increases towards the back, with the end of the abdomen being totally black
5. The female abdomen has much more uniform stripes 

image taken from: http://en.wikipedia.org/wiki/Sex-determination_system

And this second pic is a real life picture of a female (on the left) and male (on the right).

image taken from: http://www.berkeley.edu/news/media/releases/2002/07/03_paras.html

One last thing, if you look reeeally closely, you can see that the males have a row of dark bristles on their front legs - this is called the sex comb:

image taken from: https://www.mtholyoke.edu/courses/cwoodard/biol210/biol210labman.html

image taken from: https://www.caymanchem.com/app/template/Article.vm/article/2178

This picture gives shows really clearly where the sex comb is on a males front leg (A), and what the sex comb actually looks like close up. 

If you keep these differences in mind, it will help you when you are setting up your crosses in week 1 of the experiment and analysing the results of the crosses in your next class....