Ecological Relationships & Food Web ET

Two examples of ecological relationships are described below:

• Example 1: Bees gather nectar and pollen from flowering plants, providing food for the bees. As bees move from flower to flower, some pollen is transferred, helping plants reproduce.

• Example 2: Orchids grow on tree branches high in the canopy to access sunlight. They use water and nutrients from rain runoff but do not harm or benefit the tree.

What is the main difference between the ecological relationships in Example 1 and Example 2?

• Example 1 is mutualism, where both species benefit; Example 2 is parasitism, where one species is harmed.

• Example 1 is commensalism, where one benefits and the other is unaffected; Example 2 is mutualism.

• Example 1 is mutualism, where both species benefit; Example 2 is commensalism, where one benefits and the other is unaffected.

• Example 1 is parasitism, where one is harmed; Example 2 is mutualism, where both benefit.

Tags

B.13.A

Lichens are organisms made up of a fungus and an alga living together. The fungus provides a protective structure and absorbs moisture, while the alga performs photosynthesis to produce food that both organisms use.

Which answer choice correctly identifies the ecological relationship between the fungus and the alga?

• The relationship is parasitism because the fungus absorbs the alga’s food.

• The relationship is commensalism because only the alga benefits.

• The relationship is mutualism because both the fungus and the alga benefit.

• The relationship is competition because both try to get the same resources.

Tags

B.13.A

Cleaner shrimp are small crustaceans that eat parasites and dead skin off larger marine animals, such as sea cucumbers. The sea cucumber benefits from reduced irritation and infection, while the shrimp get an easy source of food.

Which answer best describes this relationship?

• Predation, because the shrimp feed on the sea cucumber

• Commensalism, because only the shrimp benefit

• Parasitism, because the shrimp harm the sea cucumber

• Mutualism, because both the shrimp and sea cucumber benefit

Tags

B.13.A

Spanish moss often hangs from oak tree branches in humid environments. It uses the tree only for physical support and absorbs nutrients from the air and rain. The oak tree is not harmed or helped.

Which term best describes the relationship between the Spanish moss and the oak tree?

• Commensalism

• Mutualism

• Parasitism

• Competition

Tags

B.13.A

Identify and explain ONE effect that the removal of krill would have on the food web.

Review the food web carefully. Then enter your answer and your explanation in the box provided.

Tags

B.13.B

A developer clears a large section of rainforest to build housing and roads. Over time, scientists observe a sharp decrease in the number of bird and insect species in the area.

What is the most likely explanation for this loss of biodiversity?

• Clearing the land increased available habitat for native species

• The ecosystem became more stable due to human activity

• Destruction of habitat led to loss of food and shelter for many species

• Fewer species led to more energy being available for the remaining organisms

Tags

B.13.B