A) Identify the process that take place in parts labeled A and B

Here are the answers to the questions about the nephron diagram:

a) Identify the process that take place in parts labeled A and B

• Part A (Glomerulus and Bowman's capsule): Ultrafiltration
• Part B (Proximal Convoluted Tubule): Selective reabsorption

b) In the part labeled A the pressure is highly increased. Name two conditions that facilitate this.

1. The afferent arteriole (leading into the glomerulus) has a wider diameter than the efferent arteriole (leading out of the glomerulus), creating resistance to blood flow and building up pressure.
2. The glomerulus is a dense network of capillaries, which also contributes to the high resistance and pressure.

c) What are the adaptations of the part labeled B,
Part B, the Proximal Convoluted Tubule (PCT), is adapted for efficient selective reabsorption:

• It has a brush border (microvilli) on its epithelial cells, which significantly increases the surface area for reabsorption.
• The cells contain numerous mitochondria to provide ATP for active transport of substances like glucose, amino acids, and ions.
• It has a long and convoluted structure, which increases the time available for reabsorption.
• It is surrounded by an extensive peritubular capillary network to quickly absorb reabsorbed substances and maintain a steep concentration gradient.