Q1. A population of 200 healthy fishermen was followed for development of Schistosomiasis. After being followed for 4 years 20 developed Schistosomiasis. 30 fishermen were followed for 6 years and they left for other jobs. The remaining who never developed Schistosomiasis was followed for 8 years.

a. compute the number of person years of observation accrued by the population.

b. determine the Incidence rate of Schistosomiasis amongst fishermen.

Q2. While a tall homozygous plant was crossed with a short homozygous plant, the F1 offspring were all tall. No short plants were present in the F1 generation. Which principle does this situation represent?