What scientific principal stated the chance of a child's gender?

What is the chance of two parents with blood types ab and o producing an offspring with blood type o a.0% b.25% c.75% d.50%

The is an estimate of the fewest number of organisms a population needs to avoid extinction. this measurement will most if the number of offspring each female in the population produces increases. if the population's this measurement will most likely increase. 1 population density, minimum viable population, carrying capacity 2 decrease, be unaffected, increase 3 death rate increase, dead rate decrease

2. which is the last step in the scientific method?