10. Which of the following is not an effect of mari- juana use? \( \begin{array}{ll}\text { a. poor concentration } & \text { c. drowsiness } \\ \text { b. giddiness } & \text { d. increased alertness }\end{array} \)

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.

Em 1950, a população de girafas numa região do Quénia era de 4600 indivíduos. Sabe-se que a taxa de decrescimento da população é \( 3,5 \% \) por década. Admitindo que a taxa de decrescimento se mantém constante a longo prazo, responda às questões que se seguem.

Embroynic in character on the cell retain the ability to divide. These tissues present in mature plant are called meristematic Thoes plant tissues which

(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