Which of the following statements about the pathogen-specific response is true?
A. There is never a gene-for-gene response.
B. If the R gene product is not triggered, no disease will occur.
C. Avr and R gene pairs have been cloned in species pathogenized by microbes, fungi, and insects.
D. The pathways involved always trigger the hypersensitive response.
E. The pathogen is recognized by its avr gene product.
Answer: E
You might also like to view...
Decomposers
A. break down dead organic matter in the environment by secreting digestive enzymes. B. break down living organic matter by secreting digestive enzymes. C. destroy living cells and then break them down with digestive enzymes. D. live in close association with another species.
You have conducted an Ames test on a given compound. Which of the following would be classified as a positive result on the Ames test?
A) his – strain grows on an his – plate. B) his – strain grows on an his+ plate. C) his+ strain grows on an his – plate. D) his+ strain grows on an his+ plate. E) his+ strain grows on either an his – or an his+ plate.
Dasypeltis scabra is one of the best studied species of egg-eating snakes. Which of its following characteristics would strongly suggest that it has a built-in egg-cracker?
a. pushing the egg against the rim of the bird's nest b. pushing the egg against ventral hypophyses c. pushing the egg out of the mouth d. pushing the egg against a ribbed trachea
Clements proposed the climax-pattern model of succession. Governing factors for this model include
A. soil conditions. B. climate. C. each successive community preparing the way for the next. D. All of the choices are correct.