One important function of sodium is to assist in bone formation. maintain fluid balance. synthesize thyroid hormones. detoxify the liver.

Calculate the cfu/cm \( \mathrm{cm}^{2} \) for a tested surface of 4 cm in length and 3 cm in width if the number of colonies on the agar plate is 96 cfu. (A) \( 8 \mathrm{cfu} / \mathrm{cm}^{2} \) (B) \( 12 \mathrm{cmu} / \mathrm{cm}^{2} \). (C) \( 72 \mathrm{cmu} / \mathrm{cm}^{2} \) (D) \( 128 \mathrm{cmu} / \mathrm{cm}^{2} \)

(A) State ONE example of selective media that can be used to isolate [3 marks] EACH of the following microorganisms. (i) Gram positive bacteria. (ii) Staphylococci spp. (iii) Gram negative bacteria.

(C) State TWO ways in which fermentation process helps to improve [2 marks] quality of food products.

23 Which one of the following microorganisms moves using flagellum? (A) Amoeba. (B) Euglena. (C) Paramecium. (D) Plasmodium. Which one of the following is NOT a heterotrophic microorganism? \( \begin{array}{ll}\text { (A) } \quad \text { Diatoms. } \\ \text { (B) } \quad \text { Sarcodines. } \\ \text { (C) } \quad \text { Sporozoans. } \\ \text { (D) }\end{array} \)

What one of the following are the CORRECT operating conditions when autoclaving biohazard wastes? (A) \( 10 \mathrm{psi} 121^{\circ} \mathrm{C} \) for 15 minutes. (B) \( 10 \mathrm{psi}, 121^{\circ} \mathrm{C} \) for 30 minutes. (C) \( 15 \mathrm{psi}, 121^{\circ} \mathrm{C} \) for 15 minutes. (D) \( 15 \mathrm{psi}, 121^{\circ} \mathrm{C} \) for 30 minutes. After conducting microbiology experiment, a laboratory technician is required to dispose the remaining culture broths. Which one of the following is the CORRECT disposal method? (A) Incineration. (B) Discard as normal waste. (C) Collection by licensed waste collectors. (D) Autoclave before discarding into the drain.