Which factor has caused primary productivity in Amazon forests to decline steadily over the past 30 years?
a. ocean acidification
b. nitrogen fixation
c. soil runoff
d. increasing droughts
e. depletion of oxygen in the atmosphere
ANSWER: d
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A test procedure that applies a specific fluorescent dye-antibody complex to a slide to which the patient specimen has been applied is referred to as a(n):
a. solid-phase enzyme immunoassay. b. direct fluorescent antibody test. c. indirect fluorescent antibody test. d. radioimmunoassay.
Which of the following is NOT true concerning
nectar? It is a. sucrose-rich. b. a dilute fluid. c. the only food for most butterflies. d. rich in vitamins and minerals. e. easy for pollinators to sip.
The hypocotyl connects the radicle with the cotyledons
____________________ Indicate whether the statement is true or false.
Which bird trait is an adaptation that is probably less well developed in flightless birds such as penguins and ostriches?
A) honeycombed bone structure B) amniotic egg C) vertebrae D) presence of feathers