Reading a litter

Every rabbit carries two copies of each gene, one from each parent. Some versions hide behind others, so a rabbit can carry a gene without showing it. A litter is how you find out.

Dominant and hidden

Take dilute, the D gene. D (dense) hides d (dilute). A rabbit with D/D or D/d looks the same: full, dark colour. Only d/d shows dilute, turning black to blue, chocolate to lilac and chestnut to opal.

So when the game shows a rabbit's genes, a gene you can't see yet is a ?. Barnaby shows D/?, because he could be D/D or D/d.

A litter gives it away

Each kit gets one copy from each parent, at random. If a kit comes out d/d, it got a d from both parents, so both must carry it, and the "?" on each parent's card becomes a d. Try it: Barnaby and Biscuit both hide something.

It can take a few litters. Two D/d parents have a dilute kit only one time in four, so a small litter can miss it.

The other way round

A parent who shows a hidden version, say d/d, has nothing else to give: every kit gets a d from them. The game fills that in on the kits' cards too.

Plan with what you know

The pairing sheet in the game only uses what you know. Where a gene is still a "?", it guesses from how common each version is, so a hidden gene can still surprise you. The Coat Lab runs the same sums, and has a switch to see the true genes.