評論
打印
6. Honey bee的fungal 新題
Ingestion of food containing spores of the pathogen Ascosphaera apis causes a fatal fungal disease known as chalk brood in honeybee larvae. However, larvae must be chilled to about 30°C (normal brood-comb temperature is 33-36°C) for the disease to develop. Accordingly, chalk brood is most common in spring and in small colonies. A recent study revealed that honeybees responsible for hive-temperature maintenance purposely raised the hives' temperature when colonies were inoculated with A.apis this “fever,” or up-regulation of temperature, occurred before any larvae died, suggesting that the response is preventative and that either honeybee workers detect the infection before symptoms are visible or larvae communicate the ingestion of the pathogen. Temperature returned to normal by the end of the study, suggesting that increased temperature is not optimal when broods are not infected, as well as that the fever does not result merely from normal colony growth (i.e., an increase in the number of workers available for temperature maintenance).
6.1. The primary purpose of the passage is to
(A) discuss the findings and implications of a particular study
(B) illustrate a process that formerly had been misunderstood
(C) outline the methods used to investigate a problem
(D) provide evidence to support a controversial theory
(E) contrast alternative interpretations of certain date
6.2. According to the passage, researchers concluded that fever in honeybee coloniesis preventative because their study showed that such fever
(A) does not occur when hive temperatures are within normal range
(B) protests adult bees from contracting chalk brood infection
(C) occurs prior to the death of any larvae
(D) is more likely to occur in spring than in summer
(E) does not have an effect on uninfected broods
6.3. The passage implies that if hive temperature had not returned to normal by the end of the study in question, a probable conclusion of the researchers would have been that
(A) up-regulation of temperature is a preventative measure against chalkbrood
(B) honeybees are incapable of purposely raising hive temperatures
(C) A. apis cannot be completely eradicated throughup-regulation of temperature along
(D) honeybee larvae have a mechanism to alert adult honeybees to the presenceof A. apis
(E) honeybee larvae may benefit from increased hive temperature even when there is no A. apis present
6.4. According to the passage, which of the following is true of chalk brood infection among honeybee larvae ?
(A) Larvae in small colonies are more likely to pass the infection to adult honeybees than are larvae in large ones.
(B) Infection with chalk brood induces larvae to raise their hive's temperature.
(C) The infection is more likely to affect larvae in winter than in spring.
(D) Larvae fail to develop symptoms of the disease when their brood –comb temperature remains within the normal range.
(E) Infected larvae exhibit visible symptoms of disease for a significant time before death.
