6. List the effects that secondhand smoke has on nonsmokers. 7. List five problems that infants can have if they are born to mothers who smoke.

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) \( 128 \mathrm{cmu} / \mathrm{cm}^{2} \)

8 Which of the following is a type of universal media? (A) MacConkey Agar. (B) Baird-Parker Agar. (C) \( \quad \) Mannitol Salt Agar. (D) Trypticase Soy Agar. 9

(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.

(B) (i) Explain THREE precaution steps during decontamination of biohazard wastes in bag using an autoclave. (ii) Describe TWO materials that will remain undamaged after autoclaving.