The toxic shock syndrome toxin is produced by some Salmonella species when there is not sufficient iron present. When iron is present, it prevents transcription of the TSS-toxin gene. Iron therefore serves as __________.

TLS Online TPP Program

#Question id: 9254

#Unit 9. Diversity of Life Forms

Organisms evolve over generations to become adapted to the environmental conditions to which they are exposed. The diversity of organisms that

occurs in any particular area thus may be largely determined by the abiotic factors limiting survivorship and reproduction of organisms in a region. Which of the following limit the range of Saguaro cactus in North America?

I) pollinators

II) sunlight

III) precipitation

IV) temperature

TLS Online TPP Program

#Question id: 9255

#Unit 9. Diversity of Life Forms

Studying species transplants is a way that ecologists ________.

TLS Online TPP Program

#Question id: 9256

#Unit 9. Diversity of Life Forms

Which of the following areas of study focuses on the exchange of energy, organisms, and materials between ecosystems?

TLS Online TPP Program

#Question id: 9257

#Unit 9. Diversity of Life Forms

Which lake zone would be absent in a very shallow lake?

TLS Online TPP Program

#Question id: 9258

#Unit 9. Diversity of Life Forms

Which of the following is characteristic of most terrestrial biomes?

TLS Online TPP Program

#Question id: 9259

#Unit 9. Diversity of Life Forms

The oceans affect the biosphere in all of the following ways except