During  a  field  trip,  an  instructor  touched  a  moth  resting  on  a  tree  trunk.  The  moth  raised  its  forewings  to  reveal large eyespots on its hind wings. The instructor asked why the moth lifted its wings. One student answered that sensory  receptors  had  fired  and  triggered  a  neuronal  reflex  culminating  in  the  contraction  of  certain  muscles.  A second student responded that the behaviour might frighten predators. Which statement best describes these explanations?

#Question id: 12215

#Unit 7. System Physiology – Animal

#Question id: 10521

#Unit 6. System Physiology – Plant

Which is an example of a plant-derived DAMP found in tomato that is produced in response to wounding associated with herbivore activity?

#Question id: 5526

#Unit 5. Developmental Biology

The allantois

#Question id: 11491

#Unit 2. Cellular Organization

#Question id: 12084

#Unit 10. Ecological Principles

In bottom sediments of lakes and streams, organic matter is broken down by heterotrophic microorganisms and ammonia is released. Under aerobic conditions, specialized bacteria convert ammonia to nitrate (nitrification). This nitrate, together with nitrate from other sources, diffuses into the deeper sediments, where it may undergo anaerobic conversion to nitrogen gas (denitrification). These sediments typically contain oligochaete worms that live with their heads buried and their tails waving back and forth in the overlying water. Plastic columns were packed with freshly collected  stream  sediments  and  then  covered  with  layers  of  nitrate enriched  water.  A  similar  set  of  columns  was packed with sediment that had been sterilized and then covered with either nitrate-enriched water or distilled water. Oligochaete  worms  were  collected  and  acclimated  to  20°(C)Following  acclimation,  worms  were  rinsed  in  distilled water and then added to three sediment columns. The columns were incubated in the dark at 20°C and monitored every three days for changes in the concentration of nitrate in the overlying water. Nitrate concentrations in each of the experimental treatments were plotted against time, as shown in the graph below.

The best explanation for the increase in nitrate concentration in one treatment is that