1. Here are a few questions to test your knowledge and understanding of the variation!

2. Give one example of how the environment affects phenotype in animals Write answer here: (three lines max!)

3. Mutations in genes can create new characteristics True False

4. Fill in the Blanks! E.coli is a bacteria which normally digest [glucose0 as a source of energy due to its abundance in the environment. However, they do possess the ability to digest ______________ (another sugar which is a source of carbohydrate which E.coli can digest to use as a source of energy). BUT ______________ needs to be present in order for this to occur. Therefore in its presence, the ____________________ is switched on. HOW? The ______________ is absorbed into the E.coli which binds to a repressor protein which is bound to the operator gene of the ____________________. The binding to the repressor protein causes it to change shape and ______________________ from the gene. This allows DNA polymerase to read the ____________________ and produce the following enzyme ______________________________ which converts ______________ into ______________.

5. Why is variation important? Write answer here: (two lines!!)

6. State 3 ways in which meiosis creates new chromosome combinations 1) 2) 3)

7. ANSWERS Give one example of how the environment affects phenotype in animals >>examples: Plants! They grow better when there is more sunshine or there are more nutrients in the soil such as nitrates, phosphate and potassium. Artic Fox’s! They change their fur colour according to what season it is for the most advantagous camouflage to avoid being targeted by predators. In winter, their fur is white to blend in with the snowy surroundings compared to summer where their fur is brown to blend in with the wooded environment. If the fox still expressed brown fur in winter they would be very easy to pick out amongst a white snowy environment! Mutations in genes can create new characteristics >>True

8. ANSWERS CONT.. Fill in the Blanks E.coli is a bacteria which normally digest glucose as a source of energy due to its abundance in the environment. However, they do possess the ability to digest lactose (another sugar which is a source of carbohydrate which E.coli can digest to use as a source of energy). BUT lactose needs to be present in order for this to occur. Therefore in the presence of lactose, the lac operon is switched on. HOW? The lactose is absorbed into the E.coli which binds to a repressor protein which is bound to the operator gene of the lac operon. The binding to the repressor protein causes it to change shape and dissociates from the gene. This allows DNA polymerase to read the lac operon and produce the following enzyme B-galactosidase which converts lactose into glucose. Why is variation important? >> Individuals within a species are different because some will possess more advantagous alleles which may increase the organism chances of survival i.e. they are better adapted to their environment than others. This process is managed and maintained through natural selection! State 3 ways in which meiosis can create new chromosome combinations >>1)independent assortment of chromosomes 2) crossing over 3) mutations