Working with word combinations and sentences.

Give English equivalents of the following word combinations.

Способ питания, неограниченный рост, деление клеток, жесткие стенки, двигательный орган, цветковые растения, развить специальные клетки, выполнять функции, перемещать питательные вещества, наземный ареал, обширная корневая система, впитывать воду, значительное эволюционное развитие, увеличить ширину, значительное многообразие, специализированная проводящая система.

Translate into English.

Тканью называется группа клеток, структурно и функционально взаимосвязанных друг с другом, сходных по происхождению, строению и выполняющих определенные функции в организме. Ткани возникли у высших растений в связи с выходом на сушу и наибольшей специализации достигли у покрытосеменных, у которых их выделяют до 80 видов. Важнейшими тканями растений являются образовательные, покровные, проводящие, механические и основные. Они могут быть простыми и сложными. Простые ткани состоят из одного вида клеток (например, колленхима, меристема), а сложные — из различных по строению клеток, выполняющих кроме основных и дополнительные функции (эпидерма, ксилема, флоэма и др.).

 

 

Working with texts

Read and translate the text.

Text 1

Plants

A

Plants (kingdom Plantae) are multicellular, eukaryotic life forms fundamentally characterized by (1) an almost exclusively photosynthetic mode of nutrition, in which the plants produce chemical energy (in the form of sugars) from water, minerals, and carbon dioxide with the aid of pigments and the radiant energy of the Sun, (2) essentially unlimited growth at localized regions of cell divisions called meristems, (3) cells that contain cellulose in their walls and are therefore more or less rigid, (4) the absence of organs of locomotion, resulting in a more or less stationary existence, (5) the absence of sensory and nervous systems, and (6) life histories that show an alteration of haploid and diploid generations (the dominance of one over the other is taxonomically significant).

B

Angiosperms are members of the more than 250, 000 species of flowering plants, the largest and most diverse group within the kingdom Plantae. Angiosperms represent approximately 80 percent of all the known green plants now living. The angiosperms are vascular seed plants in which the ovule (egg) is fertilized and develops into a seed in an enclosed hollow ovary. Fruits are derived from the maturing floral organs of the angiospermous plant and are therefore characteristic of angiosperms.

C

The specialization of the plant body, which has evolved as an adaptation to a principally terrestrial habitat, includes extensive root systems that anchor the plant and absorb water and minerals from the soil; a stem that supports the growing plant body; and leaves, which are the principal sites of photosynthesis for most angiospermous plants. Another significant evolutionary advancement over the nonvascular and the more primitive vascular plants is the presence of localized regions for plant growth, called meristems and cambia, which extend the length and width of the plant body, respectively.

D

The angiosperms dominate the Earth's surface and vegetation in more environments, particularly terrestrial habitats, than any other group of plants. As a result, angiosperms are the most important ultimate source of food for birds and mammals, including humans. In addition, the flowering plants are the most economically important group of green plants, serving as a source of pharmaceuticals, fibre products, timber, ornamentals, and other commercial products.

E

Bryophytes - nonvascular plants, in which all cells in the plant body participate in every function necessary to support, nourish, and extend the plant body (e.g. photosynthesis, and cell division). Bryophytes are among the simplest of the terrestrial plants. Most representatives lack complex tissue organization, yet they show considerable diversity in form. They are widely distributed throughout the world and are relatively small compared with most seed-bearing plants. Most are 2–5 centimetres tall or, if reclining, generally less than 10 centimetres long. The phylum Bryophyta includes three main evolutionary lines: the mosses, the liverworts, and the hornworts.

F

In gymnosperms (e.g., conifers), the other large group of vascular seed plants, the seeds do not develop enclosed within an ovary but are usually borne exposed on the surfaces of reproductive structures, such as cones, that originally produced the spores. It was in 1825 that the Scottish botanist Robert Brown first distinguished gymnosperms from angiosperms. Currently, about 60–70 genera are recognized, with a total of 700–800 species.

G

Lower vascular plants are any of the spore-bearing vascular plants, including the ferns, club mosses and horsetails.

Vascular plants are those that possess a specialized conducting system for the transport of water, minerals, and food materials, as opposed to the more primitive bryophytes—mosses and liverworts—which lack such a system.

 

 

Give a title to each paragraph.

A
B
C
D
E
F
G

 

 

Pair work. Ask and answer 6 questions to Text 1.

Read the texts using your dictionary.

Retell one of the texts.

Text 2

Pollination

The transfer of pollen from the anthers to the stigma is called pollination. Cross-pollination – when the pollen grains are carried away on the bodies of insects or simply blown by the wind and may land on the stigma of another flower. In self-pollinating plants the pollen comes from the same flower or another flower of the same plant.

Wind-pollinated flowers are adapted to their method of pollination by producing the large quantities of light pollen. They have anthers and stigmas which project outside the flowers. Some grasses have anthers which are not rigidly attached to the filaments and can be shaken by the wind. The stigmas of grasses are feathery and act as a net which traps passing pollen grains.

Grasses, cereals and many trees are pollinated not by insects, but by wind currents. The flowers are often quite small and inconspicuous. They produce no nectar.

The anthers and stigma are exposed to the air. The pollen grains, being light and smooth may be carried long distances by the wind and some of them will be trapped on the stigmas of other flowers.

Insect-pollinated flowers are considered to be adapted in various ways to their method of pollination. In the course of evolution the structure and physiology of a flower have been modified in ways which improve the chances of successful pollination by insects.

Most insect-pollinating flowers have brightly colored petals and scent, which attract a variety of insects. Some flowers produce nectar.

 

Text 3

Venus Flytrap

Flytraps actually get a good deal of their sustenance like other plants do, through the process of photosynthesis. However in addition to synthesizing glucose, plants also need to make amino acids, vitamins and other cellular components to survive. To accomplish this, plants need additional nutrients like:

nitrogen - to make amino acids, nucleic acids, proteins;

phosphorus - as part of the energy-carrying ATP molecule;

magnesium - as a co-factor that helps many enzymes function;

sulfur - to make some amino acids;

calcium - as an enzyme co-factor and to make plant cell walls;

potassium - to regulate water movement in and out of the plant.

In the bogs favored by Venus Flytraps, the soil is acidic, and minerals and other nutrients are scarce. Most plants can't survive in this environment because they cannot make enough of the building blocks necessary for growth. The Venus Flytrap has evolved the ability to thrive in this unique ecological niche by finding an alternate means of getting key nutrients like nitrogen. Living creatures like insects provide a good source of the nutrients missing from the soil, and they also contain additional energy-laden carbohydrates.

In the case of the Venus Flytrap, the leaves forming the trap secrete a sweet nectar that draws in insects searching for food.

When an insect lands or crawls on the trap, it is likely to run into one of six, short, stiff hairs on the trap's surface. These are called trigger hairs, and they serve as a primitive motion detector for the plant. If two of these hairs are brushed in close succession, or one hair is touched twice, the leaves close down upon the offending insect within half a second.

If there is no further stimulation of the hair, the trap stays in its partially shut state until tension can be re-established in the leaves of the trap. This process takes about 12 hours, at which point the leaves spread apart again. The unwanted object either falls out as the leaves re-open or is blown out by the wind.

Once the trap fully closes, the leaves form an airtight seal so that:

digestive fluids and insect parts are kept inside the trap,

bacteria and molds can't get in.

To make sure that the insects are contained within the trap, the edges of the leaves have finger-like cilia that lace together when the leaves press shut. These long, hair-like projections make the plant look like it has spiny teeth; but the cilia are really only used to latch the trap shut.

Once the insect is firmly ensconced in the trap, the process of digestion can begin. The trap secretes acidic digestive juices that:

dissolve the soft tissues and cell membranes of the food;

serve as an antiseptic to kill small amounts of bacteria inadvertently eaten or sealed in with the food.

The process continues until all that's left of the insect is its hard exoskeleton. Once the nutrients are depleted from the acidic bath, the plant reabsorbs the digestive fluid. This serves as a signal to reopen the trap, and the remains of the insect are usually either washed away in the rain or blown away by the wind.

 

⇐ Предыдущая567891011121314Следующая ⇒

Поделиться: