Understanding Populations and Factors Affecting Population Growth

The video tutorial explains the concept of populations, communities, and ecosystems, focusing on factors that affect population size such as food supply, competition, predation, and disease. It describes the phases of population growth, including the lag, log, stationary, and death phases, using a graph to illustrate these concepts. The tutorial concludes with a summary of the key points discussed.

What does the term 'population' refer to in ecological terms?

• A group of organisms of one species living in the same area at the same time

• The total number of ecosystems in a region

• A group of different species living in the same area

• All the plants in a particular ecosystem

Which of the following factors can cause a population to decrease?

• Abundant food supply

• Introduction of a predator

• Increase in birth rate

• Removal of a competing species

Which of the following is NOT a factor affecting population size?

• Food supply

• Predation

• Weather patterns

• Disease

What is the 'lag phase' in population growth?

• A phase where a new population settles and matures before breeding

• A phase where the population size rapidly increases

• A phase where the population size remains constant

• A phase where the death rate exceeds the birth rate

During which phase does the population growth rate become zero?

• Lag phase

• Log phase

• Stationary phase

• Death phase

What happens during the stationary phase of population growth?

• The birth rate exceeds the death rate

• The death rate exceeds the birth rate

• The birth rate equals the death rate

• The population size decreases rapidly

What typically causes the death phase in population dynamics?

• An increase in food supply

• An increase in birth rate

• A decrease in competition

• A catastrophe such as disease or predator introduction