# Population Dynamics

## Population Dynamics

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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

By |2018-04-28T08:14:54+00:00September 7th, 2016|Notes, O Level Science Notes, Ordinary Level Notes|Comments Off on Population Dynamics

### About the Author: Garikai Dzoma

He holds an Honours in Accountancy degree from the University of Zimbabwe. He is passionate about technology and its practical application in today's world.