Most teleost fish excrete ammonia. Explain why the Magadi tilapia, a fish living in highly basic water, excretes urea
What will be an ideal response?
Answer: In most fish, NH3 diffusion across the gills is accelerated when external protons ionize NH3 to NH4+. However, at a high pH (low proton concentration), this reaction is very slow, and therefore diffusion of NH3 across the gills is also very slow. These fish have an active ornithine-urea cycle in the liver, and the muscles also play an important role in urea synthesis. For these fish, excretion of urea is far more efficient.
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The erectile tissue that surrounds the urethra is the
A) corpus spongiosum. B) corpus cavernosum. C) penile urethra. D) membranous urethra. E) glans penis.
When penicillin is used to treat foot rot disease in milk cows, the milk from that cow should be discarded for at least five days after the last treatment is performed
Indicate whether the statement is true or false
Which of the following combining forms means liver?
A. peps/o B. gloss/o C. sigmoid/o D. hepat/o
When bones are joined by hyaline cartilage, such as between the epiphysis and diaphysis during growth, the joint is classified as a ________.
Fill in the blank(s) with the appropriate word(s).