In several studies of plant responses to elevated CO2 concentrations in the atmosphere, scientists often found that the stimulation of growth gradually diminished because
A. more photorespiration occurred.
B. C3 plants were replaced with C4 plants.
C. the soil did not contain sufficient nitrogen and other nutrients to support the enhanced growth.
D. the plants could not store the extra biomass.
E. weedy plants took over the experimental plots.
C. the soil did not contain sufficient nitrogen and other nutrients to support the enhanced growth.
In these studies, plants exposed to elevated carbon dioxide showed an initial increase in photosynthesis and growth but this decreased over time. The limited availability of other nutrients like nitrogen prevented the continual increase in photosynthesis and growth.
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Peptide hormones include
a. estrogens. b. growth hormone. c. melatonin. d. thyroid hormone. e. oxytocin.
What is the outstanding characteristic of the Kingdom Fungi?
A) All members are photosynthetic. B) Members absorb dissolved organic matter. C) Members absorb dissolved inorganic matter. D) All members are microscopic. E) All members are macroscopic.
Which type of plant would you most likely expect to find in a hot, dry desert environment?
a. A C3 plant b. A C4 plant c. A plant that fixes carbon only by the Calvin Benson cycle d. A CAM plant e. A plant that uses photorespiration
Individuals with galactosemia are missing the enzyme galactose -1-phosphate uridyl transferase, resulting in an accumulation of _____ and symptoms including _____
1.galactose / a musty odor 2.galactose-1-phosphate / cataracts and retardation 3.UDP-galactose / urine that darkens upon exposure to air 4.glucose / enlarged thyroid gland 5.galactose-1-phosphate / albinism