1. NCEA 2009 In cats, the polydactylism gene produces a paw with an extra digit (claw). This is a dominant trait (E). Discuss how a kitten with the normal number of digits / claws could be produced by two cats that had only produced kittens with extra digits in previous litters. In your answer you should state the genotypes of the parent cats, and explain why you have selected them. Use a Punnett square to support your answer. (Use E for dominant trait.)

3. How to complete a Test Cross A test cross is when we breed a known individual who is homozygous recessive with an individual with an unknown genotype.

4. Fundamentals for test cross We use a homozygous recessive individual because there genotypes is known. Sufficient offspring must be produced to be certain A pure bred male and female is needed to produce pure breeding litters.

5. QUESTION TWO: RABBIT BREEDING (NCEA 2007) In some breeds of rabbit, a plain coat colour is called solid; a blotchy coat colour is called broken. Broken coat (B) is dominant to solid coat (b). A breeder buys a rabbit with the broken coat trait. Discuss the process that could be used to identify whether this rabbit is homozygous or heterozygous for broken coat.

6. How to answer this question State what you would need to do…. Explain why you need to do this… What possible outcomes would there be… and what you would do Support with punnet squares MAKE SURE YOU INCLUDE THE CORRECT TERMINOLOGY

7. Answer Description recognises possibility of heterozygous and selecting for breeding B_ × with bb (Test Cross) / rabbits with broken coat/ with homozygous recessive Just Test Cross or Back Cross not sufficient. Reason for why test cross used or what possible punnet squares Cannot tell by looking at the dominant trait whether it is homozygous or heterozygous, so a cross with a rabbit that is homozygous for the recessive trait (solid) is carried out. OR Explanation may include diagram. Discussion includes reasons how to tell which rabbits are heterozygous vs homozygous If any offspring have a solid coat colour then the rabbit must be heterozygous. If there are no offspring with solid coat colour we can assume the rabbit must homozygous. May include idea that suficent offspring should be produced to be certain.

8. Extra Explain what the breeder must do to establish a pure breeding colony of Broken coat colour or solid coat colour?

9. QUESTION ONE: CELL DIVISION AND MUTATION (NCEA 2005) Discuss how the processes of meiosis and mutation can contribute to genetic variation.

10. Brainstorm What is a mutation? How does it lead to variation? Where must the mutation occur for it to be inherited? What processes in meiosis lead to variation? How does meiosis and fertilisation lead to recombination of genes?

11. Answer Describe TWO factors that contribute to genetic variation. Eg mutation change in genetic makeup of a cell meiosis - independent assortment - segregation - recombination Explain how TWO factors lead to variation. Must include the idea of inheritance. Eg Mutation – change in the genetic makeup. If this change occurs in the somatic cells, it cannot be passed on, but if in the sex cell, it may be inherited. Meiosis – each parent passes on one member of each pair of homologous chromosomes selected at random. At fertilisation the resulting zygote contains half it’s chromosome complement from each parent. Alleles from each parent are present in new individual and this gives variation. (Recombination) Discussion includes BOTH mutation and an aspect of meiosis linked to variation. The link is made when mutation in gametes allows it to be inherited and also includes the idea of random assortment