For the first part:
births add to the population
deaths subtract from the population
migration can be a subtraction or addition to a particular population
How do birth,death,family and migration rates affect the population?
What factors can affect these rates
3 answers
factors affecting these rates could be natural disasters which could in turn affect the ammount of food and thus affect the death rate/migration rate/ and birt rate
In some cultures, especially in poor and rural areas, having many children is the norm. Lack of birth control methods, needing to ensure there are enough children to look after parents in their old age, and religious beliefs contribute to large families.