Chapter 13: Osmoregulation Flashcards
What is osmoregulators?
Specialised mechanisms for regulating internal water and solute concentrations despite external environment
What is osmotic concntration?
The measure of solute concentration
What is the structural feature which retains water?
The kidneys
What is the function of the kidneys?
Removal of nitrogenous waste, regulation of water concentration and maintaining ion levels in the blood
What are some behavioural responses for retaining water?
Burrow, as the temperature is lower and higher humidity
What are so physiological mechanisms for retaining water?
Reabsorb water from cloaca, longer loop of Henle (more concentrated urine), marine vertebrates tend to be hypotonic.
What is the method to maintain water balance in humans?
osmoreceptors (in the hypothalamus), receptors are triggered, hypothalamus sends message to pituitary, ADH is released into blood, kidney increases permeability of cells in collecting ducts and the osmotic movement of water occurs
What are the structural features of plants for retaining water?
thick cuticle, reduced stomata, sunken stomata, reduced number of leaves and hair on leaves
How does stomata reduce water loss?
The gas exchange reduces the amount water lost and gained, it is replaced by the water uptake in the roots. Less stomata on the top and more on the bottom also help
How do succulents retain water?
Vacuole retains 90% of water
How do root systems help with water loss?
In dry places, the roots are long and vertical to absorb water deep down
What is a mesophytes?
Plants that live in an environment with adequate water
What is a hydrophyte?
Plants that have adapted to aquatic conditions, they don’t have water retaining features
What is a halophyte?
Plants that have adapted to salty conditions
What is ABA (Abscisic acid)?
A plant hormone that is produced in a stress situation where the stomata closes.
