Population Dynamics and Limiting Factors

The video tutorial explores the concept of population growth and the factors that limit it. It discusses how carrying capacity is determined by various biotic and abiotic factors, including birth, death, immigration, and emigration. The lesson distinguishes between density-dependent factors, such as competition and predation, and density-independent factors, like natural disasters. Through examples, it illustrates how these factors affect population dynamics and carrying capacity in different environments.

What are the main factors that determine the carrying capacity of an environment?

• None of the above

• Immigration and emigration only

• Limiting factors, both biotic and abiotic

• Birth and death rates only

Which of the following is a density-dependent limiting factor?

• Hurricanes

• Wildfires

• Competition

• Floods

How does competition affect population growth?

• It increases birth rates

• It has no effect on population growth

• It decreases death rates

• It can lower birth rates and increase death rates

What is a major force behind evolutionary change according to the transcript?

• Parasitism

• Herbivory

• Competition between species

• Natural disasters

What is the effect of stress from overcrowding on populations?

• It increases birth rates

• It decreases death rates

• It has no effect on populations

• It can lower birth rates and increase death rates

Which of the following is NOT a density-independent limiting factor?

• Floods

• Wildfires

• Predation

• Droughts

How do density-independent factors affect populations?

• They affect all populations in similar ways regardless of size

• They only affect large populations

• They only affect small populations

• They have no effect on populations

What happens to a population after a crash due to density-independent factors?

• It always recovers quickly

• It becomes extinct

• It may build up again quickly or stay low for some time

• It never recovers

What was the main method used to control hydrilla in the United States?

• Introduction of sterilized grass carp

• Mechanical removal

• Use of herbicides

• Introduction of natural predators

Why are only sterilized grass carp used to control hydrilla?

• They are native to the United States

• They are cheaper

• They are more effective

• They cannot reproduce