Question

Benign microbiota species make their home on human body surfaces and prevent the colonization of harmful microbiota species onto humans. This interaction is best considered:

Group of answer choices

A) A mutualism between humans and their benign microbiota

B) A commensalism between humans and their benign microbiota

C) Intraspecific competition between the benign and harmful microbiota

D) Interspecific competition between the benign and harmful microbiota

E) Both A & D

A classic study by MacArthur and Wilson demonstrated that as the size of islands increases, species:

Group of answer choices

A. richness increases.

B. richness decreases.

C. diversity increases.

D. diversity decreases.

E. richness and diversity are not affected by island size.

In a study of Oregon intertidal communities, little brown barnacles (Chthamalus dalii) are first to colonize disturbed areas. Over time, the community comes to be dominated by the acorn barnacle (Balanus glandula). Which mechanism of succession explains the relationship between the two species of barnacles?

Group of answer choices

A. Facilitation

B. Tolerance

C. Inhibition

D. Suppression

Which of the following is NOT a trait of a pioneer species?

Group of answer choices

A. Many seeds

B. Shade tolerant

C. Small seeds

D. Fast growing

A grassland habitat produces 5,000,000 available food calories per day from plants. If each organism in the community requires 1,000 calories per day, how many organisms could survive if feeding at the level of a primary consumer? What about if all fed at the level of a secondary consumer?

Group of answer choices

A. 50; 5

B. 50; 500

C. 500; 50

D. 5,000; 500

E. 5,000; 50

Which of the following represents how good a consumer is at obtaining energy from the available food in its habitat?

Group of answer choices

A) Assimilation efficiency

B) Ingestion efficiency

C) Net growth efficiency

D) Gross growth efficiency

Which of the following accurately depicts the flow of carbon between primary producers, consumers and decomposers?

Group of answer choices

A) primary producers -> consumers -> decomposers

B) consumers -> primary producers -> decomposers

C) decomposers -> primary producers -> consumers

D) decomposers -> consumers -> primary producers

Answer 1

Q. Benign microbiota species make their home on human body surfaces and prevent the colonization of harmful microbiota species onto humans. This interaction is best considered:

Answer- E) Both A & D

As both humans and the benign microbiota benefit from this interaction, it can be said that they are in mutual interaction or mutualism. The benign microbiota is getting its resources to live from humans and in return giving them protection against harmful microbiota. Also, the benign and the harmful microbiota belong to different species of the same ecological area that are competing for limited resources ie., human. This is also an example of interspecific competition.

Commensalism occurs when one species gets benefitted while the other species neither benefits nor gets harmed. This isn't suitable for the question given as here both the species are getting benefitted.

Intraspecific competition occurs between two populations of the same species but here we have two different species of microbiota, one is benign while the other is harmful.

Q. A classic study by MacArthur and Wilson demonstrated that as the size of islands increases, species:

Answer- A. richness increases.

MacArthur and Wilson in their study 'The Theory of Island Biogeography' gave a relationship between the size of habitat and the number of animals present in it known as the species-area curve. According to them, large areas of land contain a lot more animals than smaller areas of land thus showing that the species richness increases with the size of land.

Q. In a study of Oregon intertidal communities, little brown barnacles (Chthamalus dalii) are first to colonize disturbed areas. Over time, the community comes to be dominated by the acorn barnacle (Balanus glandula). Which mechanism of succession explains the relationship between the two species of barnacles?

Answer- C. Inhibition

The little brown barnacle could not survive and became dominated by the acorn barnacles. This shows that acorn barnacles caused harm to the community that had colonized the land before it and were thriving. Thus this interaction is an example of inhibition.  

Q. Which of the following is NOT a trait of a pioneer species?

Answer- B. Shade tolerant

Pioneer species are the species that first colonize an environment and thus they show all the characteristics that would help them to rapidly grow and spread farther in lands while also withstanding harsh conditions. Such characteristics include long roots with nitrogen-fixing bacteria, a large number of seeds, seeds withstanding dormancy for a longer period of time, asexual or air pollinated, etc. They also demand strong sunlight to fulfill the need for rapid growth. Thus shade-tolerant cannot be a trait of pioneer species.