biol+4+SACs

On this page you will find links to the various Unit 4 SACs. I will also try and give some general feedback and advice based on your SAC performances.

biol 4 DNA manipulation SAC Monday 4th August

General feedback It may be a while ago but at least you will be able to look back and say "I know so much more now" or you will be reminded to cover areas that may be still troubling you. Overall, some good responses with accurate use of terminolgy and explanation of concepts. Many of you interpreted the last two questions on huntington's alleles correctly and gave excellent responses. Well done on this because they both required you to think more deeply about the ifnormation given. Responses are still too vague sometimes. You must be specific, use data and the relevant terminology. Most of all make absolutely sure you answer the question that is actually being asked.

biol 4 inheritance SAC Thursday 21st August

General feedback Again this SAC was done very well. The only area that caused some difficulty were the pedigrees. You must be able to anaylse them thoroughly and back any statement up with **SPECIFIC EVIDENCE** from the pedigree.
 * AND finally if I see another phenotypic ratio without any reference to the phenotypes...I will...**

biol 4 evolution SAC Thursday 18th September

General feedback These weren't too bad but there are a couple areas of concern. If a question says "use information/data" then you must use it in your answer, more importantly don't rely on "outside" knowledge to support your answer, it must be from the question itself. This particularly relates to many of your answers to do with the first two phylogenetic trees. Analagous and homologous is easy to confuse and although you might know the difference being able to explain it clearly with an example is another thing. Some of you did not choose accurate examples. In my view the clear cut examples were Homologous: limbs of seal are homologous to limbs of dolphin and orca but have been modified to move on land, particularly rear ones. Analagous: body covering in seal and penguin is designed for insulation and have evolved independentyl due to similar selection pressure of cold environment.

You must also read questions carefuly and ensure that your answers are addressing them specifically. Some of you described differences between between the two phlyogentic tree but did not make it clear as to what are **two** **conclusions** that would be different.

biol 4 genetic issues SAC Thursday 16th October