Identify the causative agent of cholera and answer the following questions about cell biology and microscopy.

1. The causative agent of cholera is Vibrio cholerae.

2. a) The organelle is a Mitochondrion.

b) Part labelled B is the Outer membrane.

c) Part labelled A (cristae) provides a large surface area for the attachment of respiratory enzymes and for ATP synthesis during cellular respiration.

3. a) The function of the condenser is to focus light rays onto the specimen.

b) The function of the diaphragm is to regulate the amount of light passing through the specimen.

4. a) Three ways a red blood cell is adapted to its function:
   • It has a biconcave shape which increases its surface area to volume ratio for efficient oxygen diffusion.
   • It contains haemoglobin, a red pigment that binds reversibly with oxygen.
   • It lacks a nucleus and other organelles, providing more space for haemoglobin, thus increasing its oxygen-carrying capacity.

b) Carbon (IV) oxide is transported primarily as bicarbonate ions in the plasma.

5. i) The function of a centriole is to form spindle fibres during cell division in animal cells.

ii) The function of the nucleolus is to synthesize ribosomal RNA (rRNA) and assemble ribosomes.