A veterinary scientist compares blood plasma entering the glomerulus with filtrate collected from Bowman's capsule in a healthy rabbit. Water, glucose, urea and mineral ions are found in both samples, but large plasma proteins are found only in the blood plasma.
Which explanation best accounts for the distribution of the large plasma proteins?
the large protein molecules are too large to cross the filtration barrier at the glomerulus
the glomerulus actively transports the large proteins from the filtrate back into the blood
the large proteins are changed into urea as the blood passes through the glomerulus
the large proteins enter Bowman's capsule and are reabsorbed before the filtrate is collected
94 exam-style questions on Edexcel GCSE Biology 7.4 Blood glucose and the urinary system, covering 7.4.1 Insulin and blood glucose control, 7.4.2 Glucagon and blood glucose regulation, 7.4.3 Type 1 and type 2 diabetes, 7.4.4 Structure of the urinary system, 7.4.5 Structure and function of the nephron, 7.4.6 ADH and water regulation, 7.4.7 Treatments for kidney failure, and 7.4.8 Production of urea in the liver. Each one has a worked solution and a mark scheme showing where the marks go.