Mb-guous Mcq-s

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King Cobra
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Mb-guous Mcq-s

Post by 2810712 » Wed Apr 06, 2005 4:40 am

See this MCQ-
1].Mr.X was given two liters of water to drink. Then some chemical was injected in his blood.
 Then the volume of urine excreted was much lesser than the output without the injection.
The injection probably contained-
a] Salts
b] ADH
c] Oxytocin
d] Urine reducing hormone

Now, I guess that salts cannot increase BP to that extent inorder to increase the urine volume immensely, so ADH is the ans. but i wanted to confirm or see your opinions.

2]1. In the urine of ureotelic organisms , the % of _ _ _ is the highest.
 Choose the appropriate word to complete the sentence.
a] urea
b] ammonia
c] guanine
d] none of these

See IMO ans is none of these but WATER, what do u think???

3] 3. Which is true-
a] excretion = osmoregulation only
b] excretion = removal of metabolic wastes only
c] excretion = maintaining pH of body fluids only
d] none of these

Ans is surely d] , but I got some qs in my mind due to this MCQ,
Are there any substances which directly get excreted after their absorption by the intestine in blood- probably some ammounts of drugs directly get ecxreted or even some amounts of B/C vitamins, isn't it ? ?? So, they are NOT metabolic wastes , if you don't call digestion as a metabolism. But, can we call digestion in the tract as a metabolic process [ 100% catabolism and 0% anabolism ] , i think no as it is extracellular. :roll: But when some microbes secrete some enzymes to digest their foods outside their body, do we call it a metabolism ? ? ? no, so digestion is NOT a metabolic process. Am I RIGHT ? ?? please help.

Sorry, the post is extending too long -here is an MCQ which may have MULATIPLE ANS's
2]. The secretion of some hormone is stimulated by light. So, its secretion may differ in-
a] total blinds and normal people
b] people blind with one eye and normal people
c] people with less visible ability [but having two eyes ] and normal people
d] people living mostly in dark and normal people
e] people living under light in the night also, and normal people
f] people having one normal and one eye with less visible ability & normal people
- I think all are correct, what's ur ans.???



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Inland Taipan
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Post by MrMistery » Wed Apr 06, 2005 8:22 pm

1. The main effect of ADH on the organism is that it increases the amount of water reabsorbed in the nefron=> more concentrated urine. ADH is deffinetly the answer here
2. From what substance they excrete organisms can be aminotelic, ureotelic and uricotelic. They specify ureotelic organisms, which means the main way which they exrece nitrogen is through urea. The corect answer is water, but i'm guesing that the answer they are looking for is urea. I'm not sure though
3. I would go with the "none of these answer". Just think that urine contains mineral ions, which do not come from metabolism.
4. I think melatonin is the perfect example here. SO
a) true, since the brain gets it's info of how much light there is outside from the retina.
b)false, the human has a binocular vision, so it really doesn't matter if you see with one eye or both
c)false. The retina contains 2 kinds of cells: cones and rods. In the detection of light, mostly rods do the job. When it comes to shape and color, the cones get to work. A person with less visibility ability means that the image is not formed in the foveea centralis, where there are only cones, but somewhere else. But the detection of light is influenced by this in an extremely small percent. So it really doesn't matter...
d) and e) true, obviously
f) flase, same explanation as in c)
I am pretty sure about this, but i wouldn't bet my life on it :D
Hope to be of some help
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter

King Cobra
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Joined: Thu Jan 20, 2005 12:19 pm

Post by 2810712 » Thu Apr 07, 2005 6:30 am

Thanks Andrew, you were really helpful.
About 3.
b)false, the human has a binocular vision, so it really doesn't matter if you see with one eye or both [/color ]
But , nereve activation would probably differ as nerve impulses undergo summation at junctions, Optic nerves probably don't form any junction [ i really don't know, i'm guessing] still the amount of activation would probably differ , as 1 activator nerve and 2 activators are there respectively.
I will get the ans. this sunday [ test discussion day ]from my teacher and then tell you his opinion.

thanks for help, hope that many other bioguys also participate here.


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