Задание: Измените залог предложения, сохранив грамматическое время. Составьте утверждение, вопрос, отрицание

Урок 8.

Этапы занятия:

I. Проверочная работа

Вариант 1

Задание 1: Измените залог предложения, сохранив грамматическое время.

Составьте утверждение, вопрос, отрицание.

1. Scientists studied Biology for several centuries

2. Students will use the microscope at practical classes

3. Cells will perform all vital physiological functions.

4. The extracellular fluid surrounds the cell.

Задание 2. Переведите на английский:

1. жизненно важные условия окружающей среды

2. кодировать белки

3. отделять цитоплазму

Вариант 2

Задание 1: Измените залог предложения, сохранив грамматическое время.

Составьте утверждение, вопрос, отрицание.

1. Cytology studies the cell.

2. Students attend classes.

3. A cell will copy its genetic information

4. Mutations killed the cell.

Задание 2. Переведите на английский:

1. окружать зародыш

2. многочисленные мутации

3. поддерживать питание

Вариант 3

Задание 1: Измените залог предложения, сохранив грамматическое время.

Составьте утверждение, вопрос, отрицание.

1. The University will grant the Diploma.

2. Students performed many laboratory works

3. The genes encode proteins.

4. Mutations provide the mechanisms to acquire new properties

Задание 2. Переведите на английский:

1. вредная среда

2. приобретать свойства

3. обнаруживать (открывать) клетки

Вариант 4

Задание 1: Измените залог предложения, сохранив грамматическое время.

Составьте утверждение, вопрос, отрицание.

1. A lecturer delivered the lecture on Monday.

2. Scientists will replicate cells.

3. A cell membrane separates the cytoplasm

4. A cell synthesized protein molecules.

Задание 2. Переведите на английский:

1. воспроизводить белковую молекулу

2. обеспечивать рост

3. подразделять ткани

II. Изучающее чтение:

Задание 1. Ознакомьтесь с новой лексикой (в лексический минимум):

to view - рассматривать, изучать

prominent – заметный, выдающийся

feature – элемент, особенность, черта

nucleus (pl. nuclei) - ядро

shape - форма

size - размер

to retain – сохранять, удерживать

to bound - ограничивать

ribosome -рибосома

surface - поверхность

to anchor – удерживать, закреплять

chromosome - хромосома

to possess –владеть, обладать

to permit – позволять, допускать

passage – прохождение, проход

to contain - содержать

coil – виток, кольцо

nucleolus (pl. nucleoli) - ядрышко

to assemble – объединять, собирать

Nucleus

When viewed under a microscope, the most prominent feature of a cell is the nucleus. While its shape, size, position and chemical composition vary from cell to cell, its functions are always the same.

The nucleus is bounded by a double membrane, the nuclear envelope, the outer membrane of which is continuous with the endoplasmic reticulum and often has ribosomes on its surface. The inner membrane has three proteins on its surface which act as anchoring points for chromosomes. It possesses many large pores (typically 3000 per nucleus) 40-100 nm in diameter, which permit the passage of large molecules, such as RNA, between it and the cytoplasm. The cytoplasm-like material within the nucleus is called nucleoplasm. It contains chromatin made up of coils of DNA bound to proteins. Within the nucleus there are one or two small spherical bodies, each called a nucleolus. They manufacture ribosomal RNA and assemble ribosomes.

The nuclei contain the genetic material of a cell in the form of chromosomes. They act as a control centre for the activities of a cell.

Задание 2. Найдите в тексте ответы на вопросы:

1. What is the most prominent feature of a cell?

2. What makes cells different?

3. What types of membranes bound the nucleus?

4. Which of the membranes possesses large pores?

5. Where is the chromatin placed?

6. What functions do the nucleoli perform?

7. What are the main functions of the nucleus?

III. Grammar

Задание: Измените залог предложения, сохранив грамматическое время. Составьте утверждение, вопрос, отрицание.

1. Students will view the cell under a microscope.

2. All cells performed similar functions.

3. A double membrane bounds nuclei.

4. The inner membrane anchored chromosomes.

5. Nucleoli manufacture ribosomal RNA.

6. Nuclei regulate the activities of a cell

IV. Ознакомительное чтение c элементами устной речи. Прочтите текст, найдите информацию по различным видам микроскопов, их достоинствам и недостаткам (В качестве речевой опоры для составления монологического высказывания также может служить таблица после текста).

Microscopy

Have you ever wished you could see little bit better - perhaps to read what someone else is writing from a distance or to recognize who exactly it is in the crowd at a football match? This is how early scientists probably felt when they strained their eyes to decipher the detailed structure of organisms.

The light microscope opened up a new world of structural detail for biologists, but the wavelength of light limits the light microscope to distinguishing objects which are 0.2 µm or further from each other. This ability to distinguish two objects close together rather than to see them as a single image is called the resolving power or resolution.

So in 1933 the electron microscope was developed. This instrument works on the same principles as the light microscope except that instead of light rays, with their wavelengths in the order of 500 nm, a beam of electrons of wavelength 0.005 nm is used. This means that the electron microscope not only magnifies objects more, it also has a resolving power many thousands of times better than a light microscope. The light microscope uses glass lenses to focus the light rays, and the electron beam of the electron microscope is focused by means of powerful electromagnets. The image produced by the electron microscope cannot be detected directly by the naked eye. Instead, the electron beam is directed on to a screen from which black and white photographs can be taken.

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