Osmoregulation And Excretion Flashcards
(25 cards)
Why is water vital for animals?
Water is essential for various biological processes.
What are the major waste products of protein metabolism?
Nitrogenous compounds (ammonia, urea, and uric acid).
What is excretion?
The removal of toxic waste products from the body’s cells and tissues.
What is osmoregulation?
The process by which animals control the balance of water and solutes in their bodies.
What are osmoconformers?
Animals whose body fluids are isotonic with their surroundings.
What are osmoregulators?
Animals that expend energy to control water uptake and loss.
What challenge do marine animals face?
Dehydration in a hyperosmotic environment.
What challenge do freshwater animals face?
Water gain in a hypoosmotic environment.
What challenge do terrestrial animals face?
Dehydration due to water loss through evaporation.
How do marine invertebrates osmoregulate?
They are generally osmoconformers.
How do elasmobranchs (sharks, rays) osmoregulate?
They maintain high urea concentrations in their blood.
How do marine teleosts (bony fish) osmoregulate?
They lose water and gain salt across their gills.
How do freshwater vertebrates osmoregulate?
They excrete large amounts of dilute urine.
What adaptations do terrestrial animals have to reduce water loss?
Anatomical (impermeable skin), physiological (efficient kidneys), and behavioral mechanisms.
What are the types of nitrogenous wastes?
Ammonia, urea, and uric acid.
What are the characteristics of ammonia?
Highly toxic, requires a large amount of water for excretion.
What are the characteristics of urea?
Less toxic than ammonia, requires less water for excretion.
What are the characteristics of uric acid?
Least toxic, requires very little water for excretion.
What determines the type of nitrogenous waste an animal excretes?
Its evolutionary history and environment.
What is the nephron?
The functional unit of the vertebrate kidney.
What are the key processes in urine formation?
Filtration, reabsorption, secretion, and the countercurrent mechanism.
What happens during filtration?
Blood pressure forces water and small molecules from the glomerulus into Bowman’s capsule.
What happens during reabsorption?
Useful substances are reabsorbed from the filtrate back into the blood.
What happens during secretion?
Additional wastes are actively secreted from the blood into the tubule.
