Un bebé recién nacido tiene cerca de 26000000000 células. Un adulto tiene cerca de 4,94 - \( 10^{13} \) células. ¿Cuántas células más tiene un adulto que un recién nacido? Escribe la respuesta en notación científica.

(B) State TWO ways in which flagellum helps a microorganism survive in an open environment. (2 ma All rights reserved. No part of this publication may be reproduced, stored in a retrieval sys transmitted in any form or by any means, electronic, mechanical, photocopying, reco otherwise, without the prior written permission of the Institute of Technical Education, Singapo Institute of Technical Education has made every effort to trace copyright holders, but if inadvertently overlooked any, we will be pleased to make the necessary arrangements a

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

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? \( \begin{array}{ll}\text { (A) } \quad \text { Diatoms. } \\ \text { (B) } \quad \text { Sarcodines. } \\ \text { (C) } \quad \text { Sporozoans. } \\ \text { (D) }\end{array} \)

34 (A) (i) Explain ONE purpose of air monitoring. (ii) Describe TWO factors that will affect air quality.

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