The addition of excess phosphorous causes lakes to become eutrophic because the nutrients trigger
blooms of photosynthetic cyanobacteria. Why do these blooms cause low oxygen levels in lakes?
a. Cyanobacteria use up more oxygen than they produce.
b. Excess phosphorous binds to dissolved oxygen in the water.
c. Cyanobacteria are net producers of oxygen while alive, but when they die aerobic bacteria
use oxygen while decomposing them.
d. Cyanobacterial blooms only occur in waters naturally low in oxygen.
e. Cyanobacteria are aerobic heterotrophs, consuming oxygen and producing carbon dioxide.
C
You might also like to view...
Which of the following is pyogenic (pus forming)?
A. Streptococcus fecaelis B. Streptococcus mutans C. Streptococcus pyogenes D. Lactococcus lactis
Nonpolar hormones can pass through the intestinal cell membrane without being digested, and therefore can be taken orally. Which of the following hormones are available as pills?
A. insulin and growth hormone B. thyroid hormone and steroid hormones C. calcitonin and insulin D. insulin and steroid hormones E. calcitonin and thyroid hormone
An organism's genotype is its genetic makeup. An organism's physical traits are its phenotype
a. true b. false
Based on information in the figure above, why do individuals with kidney disease sometimes become anemic?
A) The diseased kidneys destroy circulating red blood cells. B) The diseased kidneys do not secrete adequate erythropoietin. C) Excessive red blood cells are lost in the urine due to leaky filtration in the diseased kidneys. D) Kidney disease spreads to the bones and interferes with red blood cell production.