A student put an elodea plant in a test tube for 24 hours. For 12 hours, the plant received light; for the next 12 hours, the plant was kept in the dark.

The student measured the pH in both conditions. Explain why the water

became acidic at highttime. (You may use the formula for photosynthesis:

6CO, + 6H 0 -- CH, 20. + 602.)

What will happen to a population of predators if there is a sudden, temporary increase in the number of prey? a. the population of predators will be uniform with no change. b. the population of predators will increase first and then decrease slowly. c. the population of predators will increase continuously.

Neelaredoxin is a 15-kda protein that is a gene product common in anaerobic prokaryotes. it has superoxide-scavenging activity, and it is constitutively expressed. in addition, its expression is not further induced during its exposure to o2 or h2o2 (silva, g., et al. 2001. j. bacteriol. 183: 4413–4420). which of the following statements best describes neelaredoxin synthesis? a-neelaredoxin is produced at all times; levels are constant even when exposed to o2 or h2o2.b-neelaredoxin is produced at all times; exposure to o2 or h2o2 increases expression.c-neelaredoxin is produced at all times; exposure to o2 or h2o2 decreases or prevents expression.d-neelaredoxin is only produced when there is exposure to o2 or h2o2.

Which of these substances does not protect against invaders in the nonspecific immune response? a. saliva b. mucus c. tears d. urine