What are key symptoms of attention deficit/hyperactivity disorder (ADHD)? Persistent patterns of inattention, hyperactivity, and impulsivity that interfere with functioning or development. Consistent feelings of sadness and withdrawal from social interaction. Gradual development of repetitive patterns of behavior and interests. Intense episodes of euphoria followed by periods of deep depression.

(A) (i) Describe TWO disadvantages of using Replicate Organism Detection And Counting (RODAC) plate during a surface swab. (ii) Explain TWO purposes of conducting a hand swab test. 12 m

(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.

Glycerol a) Name the: (i) Process \( X \) (ii) Enzyme \( Y \) (iii) Molecule Z

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.