I. Quick check. 2. Why is sugar cane called a C4 plant?

1. Name two C₃ plants.

2. Why is sugar cane called a C₄plant?

3. When do CAM plants fix carbon dioxide?

4. Suggest which type of carbon dioxide fixation (C₃, C₄, or CAM) is most efficient:

a. If it is not hot and sunny and the carbon dioxide level is low, but water is freely available

b. In hot, dry and sunny climates where stomata are closed

c. In bright light and temperate regions where there is an ample water supply.

II. Fill in the missing words:

Term (verb)	Noun	Adjective
adapt	.......	.......
fix	.......	.......
conserve	.......	.......
separate	.......	.......
dry	.......	.......

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

adapt, hot, dry, condition, growth, compound.

IV. Match these words with their definitions:

	adaptation	A.	happening at the beginning, first
	metabolism	B.	a large amount of something in one place or area
	cycle	C.	the gas produced when animals breathe out, when carbon is burned in air or when anima or vegetable substances decay
	initial	D.	a plant such as wheat, rice or fruit that is grown by farmers, especially in order to be eaten
	sufficient	E.	the state of not having something, or not having enough of it
	wilt	F.	chemical activity in your body that uses food to produce the energy you need to work and grow
7.	concentration	G.	To continue to exist in spite of many difficulties and dangers
8.	desert	H.	To succeed in dealing with a difficult problem or situation
9.	carbon dioxide	I.	the smallest part of a living thing that can exist independently
	survive	J.	As much as is needed for a particular purpose; enough
	crop plant	K.	To stop doing something or happening
12.	cope with	L.	a number of events happening in a regularly repeated order
13.	cell	M.	if a plant wilt, it bends over because it is too dry or old
14.	cease	N.	the process by which something changes or is changed so that it can be used in a different way or in different conditions
15.	lack of	O.	a large area of sand where it is always very hot and dry

V. Find English equivalents to the following word combinations:

№	Russian term	English equivalent
1.	жаркий и сухой экваториальный регион
2.	замерзающий полярный регион
3.	пшеница, соевые бобы и рис
4.	умеренные условия
5.	маленькие поры в листьях
6.	уменьшает световое дыхание
7.	приспособлены, чтобы выполнять
8.	уменьшает потери воды
9.	высокая концентрация углекислого газа
10.	справляться с условиями пустыни
11.	выжить в очень сухом климате

VI. Give Russian equivalents to the following English terms:

№	English term	Russian equivalent
	thrive in environments
	cope with the demands
	ways of fixing carbon dioxide
	common and widely distributed
	hot, dry environments
	obtain sufficient carbon dioxide
	allow water to escape
	cease photosynthesising
	plant growth
	the loss of
	a special metabolic adaptation
	leaf veins
	the metabolic pathway
	the bundle sheath
	photosynthetic efficiency
	survive in extremely dry conditions
	occur at separate times

VII. Find synonyms among the pool of words:

Pool of words	Synonyms
1)1.thrive/2.lack/3.grow/4.absence/5.cycle/6.rotation
2)1.damage/2.harm/3.cease/4.condition/5.situation/6.finish
3)1.efficient /2.sufficient /3.ample /4.productive
4)1.annual /2.drought /3.lack of rain /4.once a year

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

1. Where do green plants thrive?

2. How do C₃ plants fix carbon dioxide?

3. What are two major disadvantages of C₃ plants in hot, dry environments?

4. How do C₄ plants fix carbon dioxide?

5. What are the bundle sheath cells?

6. What is the Hatch-Slack pathway?

7. What are two main advantages of C₄ plants in hot, dry environments?

8. What are CAM plants?

9. Why can CAM plants survive in very dry climates?

IX.Match the sentence halves. Make complete sentences:

1.	Green plants thrive in environments ranging from	A.	open their stomata (small pores in their leaves).
2.	C₃ plantsfix carbon dioxide directly	B.	the Hatch-Slack pathway.
3.	To obtain sufficient carbon dioxide, C₃ plants must	C.	carbon dioxide is first fixed into a four-carbon intermediate before it enters the Calvin cycle.
4.	C₄ plantshave evolved a special metabolic adaptation	D.	into the Calvin cycle as the three-carbon compound glycerate 3-phosphate (GP).
5.	A ring of large closely packed cells called	E.	hot and dry equatorial regions to freezing-cold polar regions.
6.	The metabolic pathway that transports carbon dioxide into the bundle sheath cells is called t	F.	which reduces photorespiration.
7.	CAM is an abbreviation for crassulacean acid metabolism, a type of metabolism first observed in the family of plants called	G.	crassulaceae (which includes the stonecrops, fleshy-leaved plants that will grow on rocks and walls).
8.	CAM plants and C₄ plants have a similar metabolism:	H.	the bundle sheath surrounds the leaf veins.

X. Read and translate the short text without any dictionary:

Fact of life:

Plants are not very efficient at harnessing energy from the sunlight they receive. Under the most carefully controlled laboratory conditions plants can reach 25% efficiency but on cloudy days the natural photosynthetic efficiency of most individual plants is about 0.1%. The annual winter evening primrose, Oenothera claviformis, has the highest natural photosynthetic efficiency at 8%, closely followed by sugar cane at 7%.

XI. Food for thought:

If C₄ plants have a greater photosynthetic efficiency than C₃ plants, suggest why all plants do not have C₄ metabolism.

<64 65 666768 69 70 >

Дата добавления: 2015-07-06; просмотров: 1069;