Ecological Succession and Keystone Species

The video tutorial covers non-negative species interactions, focusing on mutualism and commensalism, where species either mutually benefit or one benefits without harming the other. It then explores ecological succession, detailing how barren areas are colonized by pioneer species, leading to more complex communities. The role of keystone species, such as sea stars, is emphasized for maintaining biodiversity. The tutorial concludes with a summary of chapter 15 and a preview of chapter 16.

What is the term for a relationship where both species involved benefit?

• Commensalism

• Mutualism

• Parasitism

• Predation

In a commensal relationship, what happens to the species that is not benefiting?

• It is neither harmed nor benefits

• It benefits

• It is harmed

• It becomes extinct

Which of the following is an example of a commensal relationship?

• Bee and flower

• Shark and fish

• Lion and zebra

• Crane and water buffalo

What is the first stage of ecological succession in a barren area?

• Mature forest

• Colonizing community

• Secondary succession

• Climax community

Which type of plants are typically the first to colonize a barren area?

• Hardwood trees

• Mosses and lichens

• Shrubs

• Grasses

What is the term for the final stage of ecological succession?

• Intermediate community

• Climax community

• Primary community

• Pioneer community

What role do keystone species play in an ecosystem?

• They are the most numerous species

• They have a large influence on the presence of other species

• They are the largest species

• They are the least important species

What happened to species diversity when sea stars were removed from an intertidal zone?

• It slightly decreased

• It drastically decreased

• It remained the same

• It increased

Why is it important to identify keystone species in an ecosystem?

• They are the most endangered species

• They are the most aggressive species

• They help maintain species diversity

• They are the most beautiful species

Which of the following is an example of a keystone species?

• Elephant

• Sea star

• Lion

• Eagle