XII. Write a letter to your tutor telling him or her which areas of Biology you would like to specialize in and why. Use these notes to help you.

Dear Mr / Mrs (tutor’s surname),

Writing to tell you choices I have made

Specialize in (one or two of the main areas)

Reasons for choosing: interested in (plants / animals / latest ideas /

laboratory work / your own ideas)

Possible career choices: what I hope to do when I graduate

(medicine / ecology / agriculture / your own idea)

Offer to meet and discuss choices: I would like your advice and hope

we can …….

Yours sincerely,

(your full name: first name + surname)

Write 100 – 140 words.

 

XIII. Prepare a short presentation to answer the question:

‘What is the scientific method?’

Talk about:

· What is the essential aspect of a scientific experiment?

· What is constantly changed in an experiment?

· What is to be done at the end of an experiment?

 

 

Unit II. СELL

Text 2.1 Cell Theory

 

■ Essential targets

By the end of this text you should be able to:

● describe the main ideas of the cell theory

● compare the structures of animal and plant cells

as seen with a light microscope.

 

Pre-reading

■ With a partner consider the following questions and try to answer them. Then quickly scan the text to check your answers.

1. What is a cell?

2. Who discovered cells?

3. Do plant cells differ from animal cells?

■ Read the given text and make your essential assignments:

Cells were discovered in 1665 by the English scientist and inventor Robert Hooke. Hooke designed his own compound light microscope to observe structures too small to be seen with the naked eye. Among the first structures he examined was a thin piece of cork (the outer surface of bark from a tree). Hooke described the cork as being made of hundreds of little boxes, giving it the appearance of a honeycomb. He called these little boxes cells. It soon became clear that virtually all living things are made of cells, and that these cells have certain features in common.

The cell theory

The concept that cells are the basic units of life became embodied in a theory called the cell theory, which embraces the following main ideas:

·cells form the building blocks of living organisms

· cells arise only by the division of existing cells

· cells contain inherited information which controls their activities

· the cell is the functioning unit of life; metabolism (the chemical reactions of life) takes place in cells

· given suitable conditions, cells are capable of independent existence.

A typical animal cell

The structure of a typical animal cell:

· the cell has a cell surface membrane which encloses the cell contents

· the contents consist of a central ball-shaped nucleussurrounded by material calledcytoplasm

· the nucleus contains a fibrous material called chromatin

· this condenses to form chromosomes during cell division

· chromatin contains DNA, the material which controls the various activities inside the cell

· scattered within the cytoplasm are mitochondria, small rod-like structures. They have been described as the “power-houses” of the cell because they supply energy.

· smaller dots within the cytoplasm are particles of stored food. Many consist of glycogen, which is a food storage polysaccharide.

A typical plant cell

Like an animal cell, a typical plant cell has a cell surface membrane, cytoplasm, and a nucleus. However, plant cells differ from animal cells in several ways:

· most plant cells have a large sap-filled cavity called the vacuole.Sap is a watery fluid containing salts and sugars. The vacuole surrounded by a membrane called the tonoplast.

· the cytoplasm contains starch grains, the food storage products of plants

· many plant cells have chloroplasts in the cytoplasm. These contain the pigments used in photosynthesis. Chlorophyll, which is green, is the main pigment. Chloroplasts occur only in the parts of plants exposed to light – the green parts. They are absent from underground structures such as roots.

■ Glossary of essential terms for you to know

№	English term	Russian equivalent
	cork	пробка
	honeycomb	соты пчелиные
	cell	клетка
	to embody	воплощать, олицетворять
	to enclose	окружать
	contents	содержимое
	surface	поверхность
	membrane	мембрана
	nucleus	ядро
	to surround	окружать
	cytoplasm	цитоплазма
	fibrous	волокнистый, фиброзный
	division	деление
	to scatter	разбрасывать, рассыпать
	to supply	обеспечивать, снабжать
	storage	хранение
	sap	сок растения
	cavity	полость
	starch	крахмал
	root	корень
	compound	сложный
	to observe	наблюдать
	to examine	исследовать
	feature	черта
	suitable	подходящий
	existence	существование
	fluid	жидкость
	grain	зерно

■ Your Essential Assignments

I. Quick check

1. Briefly state the main concept of the cell theory.

2. List the features:

a) that only animal cells have

b) that only plant cells have

c) that both animal and plant cells have.

 

II. Fill in the missing words:

Term (verb)	Noun	Adjective
exist	.......	.......
store	.......	.......
form	.......	.......
divide	.......	.......
act	.......	.......
suit	.......	.......
differ	…..	……

III. Use monolingual English dictionary and write down what could the words given below mean:

surface, honeycomb, cavity, plant, sap.

IV. Match these words with their definitions:

1.	cell	A.	a scientific instrument that makes extremely small things look larger
2.	to observe	B.	the amount of a substance that is contained in something
3.	microscope	C.	the contents consist of a central ball-shaped nucleussurrounded by material
4.	metabolism	D.	parts of plants that can you eat but cannot digest, which help food to move quickly through your body
5.	independent	E.	the central part of an atom, made up of neutrons, protons, and other elementary particles
6.	contents	F.	to watch something or someone carefully
7.	nucleus	G.	in something
8.	cytoplasm	H.	the act of keeping or putting something in a special place while is not being used
9.	fibre	I.	the chemical reactions of life
10.	inside	J.	existing separately and not connecting with or influenced by any others
11.	storage	K.	the green-coloured substance in plants
12.	chlorophyll	L.	the smallest part of a living thing that can exist independently

V. Find English equivalents to the following word combinations:

№	Russian term	English equivalent
1.	ученый и изобретатель
2.	слишком маленький, чтобы увидеть невооруженным глазом
3.	сделаны из клеток
4.	живые организмы
5.	деление существующих клеток
6.	наследственная информация
7.	подходящие условия
8.	окружает содержимое клетки
9.	во время деления клетки
	снабжать энергией
	отличаться от ч.-л.
	содержать соли и сахара
	быть окруженным мембраной
	пигменты, используемые в фотосинтезе

VI. Give Russian equivalents to the following English terms:

№	English term	Russian equivalent
	a compound light microscope
	to serve structures
	to have certain features in common
	the basic units of life
	the cell theory
	the functioning unit of life
	it takes place in cells
	independent existence
	a typical animal cell
	a cell surface membrane
	а ball-shaped nucleus
	a fibrous material
	inside the cell
	small rod-like structures
	a food storage
	a sap-filled cavity
	starch grains
	exposed to light

VII. Find synonyms among the pool of words:

Pool of words	Synonyms
1) 1.occur /2.scatter /3. take place /4. spread
2) 1.cavity /2.sap /3.juice /4.contents /5.hole /6.ingredients
3) 1.nucleus/2.division/3.core/4.naked/5.separation/6. bare
4) 1.unit /2.part /3.fluid /4.grain /5.solution /6.corn

VIII. Answer the following questions. Use all information given before:

1. When were cells discovered?

2. How did Robert Hooke discover cells?

3. What is called the cell theory?

4. What are the main ideas of the cell theory?

5. What is the structure of a typical animal cell?

6. How do plant cells differ from animal cells?

 

IX. Match the sentence halves. Make complete sentences: