The following sub-topics are covered in this section. 

(a) Level of organisation 

(b) Cell structure 

(c) Biological molecules 

(d) Movement of substances into and out of cells 

(e) Nutrition 

(f) Respiration 

(g) Gas exchange 

(h) Transport 

(i) Excretion 

(j) Co-ordination and response

Students should:

Flowering plants 

2.70 understand the origin of carbon dioxide and oxygen as waste products of metabolism and their loss from the stomata of a leaf

Humans 

2.71 know the excretory products of the lungs, kidneys and skin (organs of excretion) 

2.72B understand how the kidney carries out its roles of excretion and osmoregulation 

2.73B describe the structure of the urinary system, including the kidneys, ureters, bladder and urethra 

2.74B describe the structure of a nephron, including the Bowman’s capsule and glomerulus, convoluted tubules, loop of Henle and collecting duct 

2.75B describe ultrafiltration in the Bowman’s capsule and the composition of the glomerular filtrate 

2.76B understand how water is reabsorbed into the blood from the collecting duct 

2.77B understand why selective reabsorption of glucose occurs at the proximal convoluted tubule 

2.78B describe the role of ADH in regulating the water content of the blood 

2.79B understand that urine contains water, urea and ions