What kind of software do you use to do your math assignment?

3.2 Explain how mutations can increase variation in a species (3)

2.4.2 State the probability that the couple’s first child will have Treacher Collins syndrome (1)

2.2 Pedigree analysis can be used to find out if characteristics are controlled by dominant or recessive alleles. The diagram below shows a family pedigree for albinism       2.2.1 Explain, using the information in the pedigree, whether albinism is controlled by a recessive allele or a dominant allele.   (3)

    Question 4

1.3 A student reads that DNA codons are non-overlapping. Suggest what is meant by the term non-overlapping. You should refer to the sequence of bases in your answer.   (2)

2.3 Sickle cell anaemia is a genetic condition that results in the formation of abnormal red blood cells. Sickle cell anaemia is controlled by a gene with two alleles. The allele (N) produces normal red blood cells, and the allele (n) produces abnormal red blood cells. Two parents who are both heterozygous plan to have children. Use a genetic diagram to show the parent genotypes, the gametes produced, and all the possible genotypes and phenotypes of their offspring. Insert a table to draw the punnet diagram, or use the space bar to separate your gametes and genotypes. (3)   Parent genotypes Gametes Offspring genotypes    

4.2 The statements below describe the different stages that led to Staphylococcus aureus (SA) becoming resistant to methicillin. Put them in the correct order by writing the numbers 1 to 4 in the boxes, where 1 represents the first stage. (2)   Stage Order The gene for methicillin resistance became more common in the population over time Individual bacteria with the mutated genes were more likely to survive and reproduce in a host being treated with methicillin. Random mutations in the DNA of  Staphylococcus aureus (SA) led to it being less affected by methicillin. The gene for methicillin resistance was passed on to lots of offspring, who also survived and reproduced.    

2.4 Treacher Collins syndrome is characterised by deformed or missing bones in the face. It is thought to be transmitted by the dominant allele T. Sever forms of the syndrome can result in life-threatening breathing difficulties.     A Man with mild symptoms of Treacher Collins syndrome is heterozygous for the gene. His wife does not have the syndrome. Before deciding whether to have children, the couple wishes to know what the probability is of their child inheriting the condition.     Complete the Punnet square to show the genotypes and the gametes of the couple, and the possible genotypes and the phenotypes of their children. Use T and t to represent the alleles. (3)      

4.1 Name the process that leads to the spread of antibiotic resistance in bacteria (1)