Population size (populations and sustainability)

Question 1

What happens during phase 1 of the population growth curve?

Answer 1

• Slow growth
• Small numbers of individuals present reproduce
• Population size increases
• Birth rate higher than death rate

Question 2

What happens during phase 2 of the population growth curve?

Answer 2

• Rapid growth
• More breeding individuals so population multiplies exponentially
• Growth not limited by external factors

Question 3

What happens during phase 3 of population growth curve?

Answer 3

• Stable state
• Population growth prevented by external constraints
• Population size fluctuates but remains relatively stable
• Birth rates = Death rates

Question 4

What are some examples of limiting factors?

Answer 4

Abiotic= Light, water and oxygen availability, temperature, pH

Biotic= Competition, predation, disease

Question 5

The maximum population that an environment can support is known as the ………..

Answer 5

Carrying capacity

Question 6

How does migration affect population size?

Answer 6

Immigration- individuals move into an area, increasing population size

Emigration- individuals move out of an area, decreasing population size

Question 7

Tsunamis, earthquakes, fires, volcanic eruptions and storms are all examples of what?

Answer 7

Density independent factors- have an effect upon population regardless of its size.