Gene Jury

Single Gene Cross

Living thing!Wee baldy sheep

Cell

NucleusChromosom

es

DNA

size gene (wee)

Genes

DNA

size gene

Genes from mumsize gene

Genes from dad

Every animal has two sets of genes, One from its mum and one from its dad

What will the sheep look like?

Size gene: big = dominant

A B

Lambing seasonYou and your partner are going to be two sheep parents,

making a lamb together. Each parent has genes and needs a card pack.

All animals have two versions of each gene, one from their mum and one from their dad. We will look at size genes today.

Each remove the two size gene cards from the pack and place them coloured side up on the table. Leave the other cards in the pack. Your

gamete

Partner’sgamete

Make a lamb by combining the gamete with your partner’sTurn over the cards to see which gene characteristics

(allelles) your lamb will carryRecord your lamb’s gene characteristics on your sheet

LAMB

Each choose one size gene card – this makes a gamete.

Now take your own cards back. Repeat the lambing process to make a

second lamb.

What did your lambs look like?

Lets work out the ratio of different lambs.

In your pairs: one of you vote for lamb 1the other vote for lamb 2.

A B