biol+4+inheritance+SAC

This SAC is based on the drosophila software that you used to carry out various experiments.

Inheritance is a large area and I will expect you to show an understanding of the following:
 * single gene inheritance-dominant/recessive/codominant/incomplete dominance
 * single gene with more than two alleles, eg blood grouping
 * two gene inheritance-linked and non-linked
 * effect of crossing over and formation of recombinants
 * indpendent assortment
 * use of test crosses
 * analysis of pedigrees

You will **not** be allowed to use a calculator (may as well emulate the exam situation). But off course this means that any calculations will have to involve reasonably straight forward numbers. You will be allowed to bring in your experiment handouts and answers to questions (on loose leaf).

Finally, I have altered the assessment for this SAC in that questions have been allocated actual marks. There are 3 sections A, B and C and a total of 7 questions. See below. Any queries relating to the SAC can be posted below.

Q. In the SAC, if we are asked to explain why a particular phenotypic ratio was observed or anything else along those lines, is it sufficient to draw a Punnet square as an explanation? //A. A punnet square on its own is not enough, it must be labelled and you should include a written comment that clearly shows you know what it is showing.VM //

--> __http://www.biology.arizona.edu/mendelian_genetics/problem_sets/dihybrid_cross/01q.html __ --> __http://trc.ucdavis.edu/biosci10v/bis10v/media/ch08/dihybrid_v2.html __ --> __http://www.slideshare.net/rossbiology/1-meiosis-and-dihybrid-cross-presentation __
 * For those who want to further test themselves, or reiterate their understanding of hybrid crosses, i found a few great websites that might help.*

//Yep all these sites are very useful, so thx LB. Hippocampus website is also really useful if you want a good summary of the relevant genetics. Link is below. VM //

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Q. hi voj, would you be able to put up suggested answers to last years sac? //A. No worries but give me some time as I don't have any ready made solutions. VM // [|biol 4 inheritance 2008 SAC sol.doc]

Q.Hi VM. would it be possible (if u have time) to upload answers to the worksheet of Genetic Inheritance? ie the long one with all the pedigrees? (just the last section on linked genes) Otherwise, would u prefer i came in to go through it? // A. I am pretty sure I gave answers (at the back of each handout). Otherwise you need to be more specific about which handout you are referring to. VM //

Q. Vojtech, i am still unsure of why you cant use recessive and dominant to name alleles, and how i should word it instead. What would i say instead of 'the offspring all received a recessive allele from both parent"? if i said 'mutant allele' in referring to r instead of R, for example, would that be correct? // A. How you word your answer really depends on the question. If symbols are given then use them. You can use "mutant" allele but be careful as a mutant allele DOES NOT imply a recessive characteristic. You can use "r" allele or you can also say "the 'r' allele is responsible for the recessive phenotype" or in your answer you can say "the offspring all recieved the allele for the recessive trait from each parent". Just don't refer to alleles as dominant or recessive, as this has been explicilty conveyed to us by the examiners as being unacceptable in year 12 biology. VM //

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