2 Excretion Flashcards
When are carbon dioxide and oxygen waste products in a leaf?
During respiration, oxygen is useful and carbon dioxide is a waste product.
During photosynthesis, carbon dioxide is useful and oxygen is a waste product.
The waste products are lost via the stomata of a leaf.
What is excretion?
the removal of waste products
What are the excretory products of the lungs?
Carbon dioxide made from aerobic respiration
What are the excretory products of the kidneys?
Urea made from excess protein
removed as urine
Water made from aerobic respiration removed as urine
Ions (salt)
What are the excretory products of the skin?
Water made from aerobic respiration removed as sweat
PAPER 2 How does the kidney carry out excretion?
Ultrafiltration, Reabsorption and Releasing waste into bladder where it is stored before being released via the urethra
PAPER 2 How does the kidney carry out osmoregulation?
Water is excreted by the kidneys in the urine.
PAPER 2 What is part of the urinary system?
aorta
vena cava
renal artery
renal vein
kidneys
ureter
bladder
sphincter
urethra
PAPER 2 What is part of the nephron?
bowman’s capsule
glomerulus
proximal convoluted tubule
loop of henle
distal convoluted tubule
collecting duct
PAPER 2 What is ultrafiltration?
renal artery flows through glomerulus
glomerulus filters out large molecules like proteins and blood cells so they stay in blood and don’t go in nephron
high pressure built up which squeezes small molecules (water, urea, ions, glucose) out of blood and into bowman’s capsule
this is called filtrate
PAPER 2 Where does ultrafiltration occur?
Bowman’s capsule
PAPER 2 What is the composition of glomerular filtrate?
water
salts/ions
glucose
amino acids
urea
PAPER 2 How is water reabsorbed into the blood from the collecting duct?
Water is reabsorbed into blood via osmosis
Collecting duct is affected by ADH which makes the collecting duct more permeable so more water is reabsorbed into the blood
This is called osmoregulation
PAPER 2 What gland releases ADH?
pituitary gland
PAPER 2 What is osmoregulation controlled by?
negative feedback. If water gets too high or low, mechanism triggered that brings it back to normal