Exploring Scientific Investigation in AP Biology

The video tutorial by Moren Jimenez for AP Biology covers a free response question on ecology, focusing on sand lances as keystone species in coastal ecosystems. It discusses an experiment examining the effects of climate change on sand lance populations, including the setup, control conditions, and null hypothesis. The tutorial also explores the impact of biodiversity on ecosystem resilience and the consequences of sand lance population reduction on ecosystem stability. Common misconceptions and study tips for ecology and experimental design are provided to help students prepare for the AP exam.

What role do sand lances play in coastal ecosystems?

• Decomposers

• Keystone prey species

• Producers of algae

• Predators of smaller fish

At what temperature do sand lance embryos typically develop?

• 15° C

• 5° C

• 7° C

• 10° C

How does increased biodiversity affect ecosystem resilience?

• Only affects aquatic ecosystems

• Increases resilience

• No effect on resilience

• Decreases resilience

What does an increase in biodiversity typically lead to in an ecosystem?

• Higher rates of pollution

• Decreased nutrient cycles

• Reduced energy transfer

• Increased resilience to disruptions

Why did scientists choose 5° C and 400 micro atmospheres as control conditions?

• These are typical development conditions for sand lances

• These are average global conditions

• These are extreme conditions

• Randomly selected for variability

What is a null hypothesis in the context of the sand lance study?

• Only CO2 levels affect sand lance survival

• No effect of temperature and CO2 levels on sand lance survival

• Temperature and CO2 levels significantly affect sand lance survival

• Only temperature affects sand lance survival

What would likely happen if sand lance populations decreased significantly?

• Increase in predator populations

• Decrease in algae levels

• Decrease in predator populations

• No change to the ecosystem

What is the importance of understanding food webs in ecology?

• To predict changes in predator populations

• To design better agricultural systems

• To understand nutrient cycles

• All of the above

Why is it crucial to know the normal functions of an ecosystem?

• To reduce biodiversity

• To create artificial ecosystems

• To predict the effects of disruptions

• To increase CO2 levels

What type of experimental controls are important in scientific studies?

• Only negative controls

• Only positive controls

• No controls are necessary

• Both positive and negative controls