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(共14张PPT)
Unit 5 Using language
listening & vocabulary
What do you know about biodiversity
bio + diversity
means “life”
means “variety”
species
gene
ecosystem
cell细胞, bacteria细菌, germs 病毒
有机的
免疫系统
P71
made up of cells
bricks that are used to build houses
thirty trillion
thirty-nine trillion
help with digestion
break down
Jenny: Hello, and welcome to Science Under the Microscope, a science programme for teens. I'm Jenny.
Josh: And I'm Josh.
Jenny: This week, as part of our series on biodiversity, we are discussing microorganisms. They are the oldest form of life on Earth. Scientists believe they first emerged around three and a half billion years ago!
Josh: That's incredible!
Jenny: But you can only see them with a microscope, as these living things are very very small. We're talking about life at the level of the cell. Do you know about cells, Josh
Josh: Erm...I'm afraid not. What exactly is a cell
Jenny: Every living thing is made up of cells. They are like bricks that are used to build houses. By the way, most microorganisms are single-celled. This means that they consist of just one cell.
Josh: How strange!
Jenny: Actually, we're the ones who are unusual. The vast majority of life on
this planet is made up of single-celled microorganisms. They're everywhere!
In the air, in water, there are even microorganisms... inside you. I'm talking
about bacteria. Have you heard of bacteria, Josh
Josh: I have, Jenny. But bacteria, inside me Yuck!
Jenny:[laughs]That's right. You have lots of them living in your body. In fact,
an average human body contains about thirty trillion human cells, and around thirty-nine trillion bacteria cells.
Josh: Seriously Oh, this is making my stomach turn.
Jenny: Speaking of which, most of the bacteria in your body help with
digestion. And they help make the food that goes into your stomach, too.
Without bacteria, we wouldn't be able to make cheese, yoghurt, vinegar...
Josh: Really I didn't know that!
Jenny: Oh, and bacteria are also useful at the other end of the
food production process. They have an important role dealing with your waste and that of other organisms.
Josh: Euw! You mean what goes down the toilet
Jenny: Yes. Bacteria break down this waster and other dead,
organic matter, like fallen leaves, into nutrients.
Josh: Oh, I get it. And these nutrients go back into the soil where they can be used by plants!
Jenny: That's it exactly.
Josh: All right. Although some of the bacteria may cause diseases in
humans, plants and animals, they aren't all bad...
Do you know about…
Have you heard of…
By the way… Actually …
In fact,… Speaking of which,…
What species are mentioned and what is special about them
Species 种类 Features特征
bacteria
& viruses
extremely small size
blue Whale
the largest size
water
bear
extreme toughness
unknown species
vast number awaiting
discovered
What other unusual life forms do you know of
What are they
giant tortoise
mangroves
iguana
coastal plants
comb-like
spines
the Galapagos islands
Match the words with their definitions
ancestor
scientific
be native to
primitive
habitat
appearance
be home to
ecosystem
E
F
D
B
A
G
H
C
源于…的
原始的，低等的
栖息地
是…的家园
生态系统
is home to
are native to
scientific
habitats
ecosystem
appearance
primitive
ancestor
Talk about biodiversity in China using the words we’ve learnt.
The desert ecosystem in Northwest China is home to the hardy diversiform-leaved poplar, which helps protect the habitat from sandstorms.
胡杨
水杉
东北虎
牦牛
Scientific research shows that the dawn redwood is a primitive tree species that was once thought to be extinct.
Siberian tigers are native to the temperate forests of Northeast China and Russia.

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