Population Concepts and Population Growth
Define the term birth rate.
The number of live births per 1,000 people in a population per year.
Give two reasons why a country's population may increase.
More babies are born than people die.
More people move into the country than leave it.
What is a natural resource? Give three examples.
A natural resource is something found in nature that people use. Examples include water, soil and forests.
Define overfishing.
Overfishing occurs when fish are caught faster than they can reproduce and replace their numbers.
According to the pie chart on page 132, which sector uses the largest percentage of water in South Africa?
Agriculture, particularly irrigation
Explain the difference between birth rate and death rate.
Birth rate measures the number of live births, while death rate measures the number of deaths per 1,000 people per year.
Why was world population growth slow for many centuries?
Disease, famine, poor sanitation and limited medical care caused many people to die.
Explain the difference between renewable and non-renewable resources. Give one example of each.
Renewable resources can be naturally replaced, such as sunlight. Non-renewable resources are limited and take millions of years to form, such as coal.
Explain two negative effects of overfishing on marine ecosystems.
Fish populations decrease.
Food chains are disrupted, affecting other marine organisms.
Which sector uses the smallest percentage of water according to the pie chart?
Power generation
Calculate the natural population growth rate if the birth rate is 28 per 1,000 people and the death rate is 12 per 1,000 people.
28 − 12 = 16 per 1,000 people.
Give two reasons why world population growth increased after the Industrial Revolution.
Answer:
Improvements in medicine and healthcare.
Better sanitation and food supplies.
Describe two ways in which people abuse natural resources.
Cutting down too many trees.
Polluting rivers with waste and chemicals.
How can overfishing affect people who depend on fishing?
Fishers may earn less money and lose their jobs when fish become scarce.
Why does agriculture require large amounts of water?
Water is needed to irrigate crops and provide water for livestock.
What is infant mortality rate?
The number of babies who die before reaching 5 year of age per 1,000 live births in a year.
Explain how improved sanitation contributed to population growth.
Improved sanitation reduced the spread of diseases, helping more people survive.
Define conservation.
Conservation is the protection and careful management of natural resources and the environment.
Give two ways to prevent overfishing.
Set limits on the number and size of fish that may be caught.
Establish marine protected areas where fishing is restricted.
Give two reasons why South Africa experiences water shortages.
Low and irregular rainfall in many areas.
High water demand from households, agriculture and industries.
Give one reason why infant mortality rates differ between countries.
Some countries have better healthcare, sanitation and access to clean water than others.
How has canned food helped people?
Canned food can be stored for long periods without spoiling quickly, making food available when fresh food is scarce.
What is ecotourism, and how does it benefit communities and the environment?
Ecotourism is responsible tourism in natural areas. It can create jobs for local people and generate money to protect wildlife and habitats.
Give three ways to reduce water wastage at home or school.
Close taps when they are not being used.
Repair leaking taps and pipes.
Use buckets instead of running hoses when washing cars.
Give two ways to protect catchment areas and maintain healthy rivers.
Prevent litter, sewage and chemicals from entering rivers.
Protect vegetation around rivers to reduce soil erosion and filter runoff.