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7.1 Osmoregulation — Test 1
Q1. Osmoregulation in Amoeba is carried out by the:✓ Contractile vacuole
Q2. Entamoeba histolytica lacks contractile vacuoles, so if placed in fresh water it will:✓ Swell and burst (it cannot expel excess water)
Q3. In humans and most mammals, the main nitrogenous waste is:✓ Urea
Q4. Insects (and most terrestrial reptiles and birds) are physiologically:✓ Uricotelic
Q5. Aquatic animals such as bony fishes typically excrete nitrogen as:✓ Ammonia (ammonotelic)
Q6. The type of nitrogenous waste an animal excretes depends mainly on:✓ The availability of water in its environment
Q7. Desert rodents can produce highly concentrated urine because they have:✓ A very long loop of Henle
Q8. The cations found in higher concentration in extracellular fluid than inside cells are:✓ Sodium ions
Q9. Adding a 5% NaCl solution to the extracellular fluid by intravenous infusion would cause cells to:✓ Lose water and shrink (the ECF becomes hypertonic)
Q10. In vertebrates, variations in nephron structure are linked mainly to the animal's:✓ Habitat and water availability
Q11. Osmoconformers are animals whose body fluid osmolarity:✓ Matches that of the surrounding medium
7.1 Osmoregulation — Test 2
Q12. Marine bony fishes tend to lose water to their surroundings because seawater is:✓ Hypertonic to their body fluids
Q13. Freshwater fishes face the problem of:✓ Water flooding in and salt loss (the environment is hypotonic)
Q14. Chloride cells in the gills of marine teleost fishes function to:✓ Actively excrete excess salt
Q15. Marine birds and reptiles cope with excess salt by using:✓ Salt glands (e.g. nasal glands)
Q16. The cockroach mainly excretes its nitrogenous waste as:✓ Uric acid
Q17. The interstitial (tissue) fluid is similar to plasma except that it has:✓ A much lower protein concentration
Q18. In which body fluid is the K⁺ concentration higher than the Na⁺ concentration?✓ Endolymph of the inner ear
Q19. Animals that maintain a constant internal osmolarity regardless of the external medium are called:✓ Osmoregulators
Q20. The conversion of toxic ammonia to less toxic urea in mammals occurs via the:✓ Urea cycle in the liver
Q21. Aquatic animals living in fresh water tend to gain water because their body fluids are:✓ Hypertonic to the surrounding water
Q22. Animals that excrete uric acid as their main nitrogenous waste are described as:✓ Uricotelic