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ZIMSEC O Level Combined Science Notes: Population Dynamics
- Population-all the inhabitants of a particular place/area at one given time
- The study of changes in population is known as demograph
Factors affecting population change
- The birth rate-the number of live births per 1000 people per year.
- Death/Mortality rate-is the number of deaths per 1 000 people per year.
- The death rate is Zimbabwe has been raised by HIV/AIDS
- Infant mortality rate-is the number of deaths of babies less than 1 year old per 1000 babies born per year
- The mortality rate of those 5 years and below gives an indication of the health services of a given country/area
- Growth rate-Birth rate-Death rate
- Migration-the movement of people in or out of an area,
- In most countries migration is not an issue
- In Zimbabwe a lot of people have emigrated due to economic hardships
Population growth
- Doubling time-is the time it takes for the population to double
- \text{Doubling time= } \dfrac{70}{\text{Percentage Growth Rate}}
- Dependency ratio-the comparison of the number of children and old people to the number of productive adults
- Children-those under 15 years of age
- Old people-those over 65 years of age
- \text{Dependency ratio = } \dfrac{\text{Number of elderly people + Number of Children}}{\text{Number of people of working age}}
To access more topics go to the Combined Science Notes page
