Pp. 39. Quick check

1. a) a magnification in a light microscope is varied by changing the power of the glass lenses.

b) magnification of an electron microscope is varied by changing the strength of the electromagnets.

2. Electron microscopes use beams of electrons which have a shorter wavelength than light, giving electron microscopes a higher resolving power than light microscopes.

3. 0.2 micrometres.

p. 40. Ex. II: magnify – magnification - magnified

multiply – multiplication – multiple

reflect – reflection – reflective

absorb – absorbability – absorbable

prevent – prevention – preventative

p. 40. Ex. IV: 1E; 2H; 3K; 4A; 5B; 6C; 7J; 8D; 9F; 10G;11I.

p. 41. Ex.VII: 1) 1-3; 2-4; 2) 1-4; 2-3; 3) 1-6; 2-4; 3-5;

4) 1-3; 2-4;

p. 42. Ex. IX: 1G; 2E; 3A; 4H; 5C; 6I; 7F; 8D, 9B.

Unit III. Text 3.1

p. 44. Ex.A.: 1C; 2D; 3E; 4F; 5G; 6A; 7B; 8I;9J; 10H

P. 47. Quick check

1. a nucleoside contains a base and pentose sugar whereas a nucleotide consists of a base, sugar, and phosphate;

2. condensation

3. TTAGGC.

pp. 47-48. Ex.II.: discover – discovery; project – project;

describe – description; receive – receiver;

remove – remove/remover;

condensate – condensation; react – reaction.

Text 3.2

p. 51. Ex. A. 1C; 2L; 3E; 4A; 5B; 6D; 7I; 8G; 9K; 10H; 11F; 12J.

P. 64. Quick check

1. a bead-like structure consisting of DNA and histones

onchromosomes;

2. control the distribution of chromosomes during cell division;

3. telomeres seal the ends of chromosomes; shoelace tips seal the

ends of shoelaces.

Unit IV. Text 4.1

p. 59. Ex. A: 1C; 2A; 3I; 4G; 5H; 6J; 7K; 8E; 9L; 10D; 11B; 12F.