Biology 9700/52 May June 2019 | Cambridge AS Level Past Papers With Mark Scheme

1. Evaluation of reaction time across age groups using different methods; identification of Method 2 (computer click timer) as most suitable due to its precision and ease of use for diverse age ranges.

2. Analysis of trends in reaction time based on age and gender, including percentage change calculations and graphical interpretations with standard deviation as error bars.

3. Statistical test selection for comparing reaction times between genders, null hypothesis formulation, and justification based on data variability.

4. Estimation of sperm count using haemocytometer grid and diluted semen sample, with calculations for original semen concentration by accounting for dilution factor.

5. Identification of variables standardized in sperm analysis studies, including abstinence from smoking, alcohol, and medications for consistency in results.

6. Hormonal analysis in infertility research, demonstrating varying concentrations of FSH and LH among fertile and infertile groups, and implications of these hormone levels on sperm motility and count.