Why do we study Biology?
Students sometimes wonder how life science - the realm of fungi and fruit flies and DNA-relates to them and why they should work hard to study and understand it. In fact, biology is one of the most relevant subjects in a modern university. Here are just a few of the reasons why.
1. If you¢re reading this, you are alive! We humans are living mammals: We are born, we eat, we grow, we have sex, we reproduce, we age, and die. We live in a range of the earth¢s ecological zones, from deserts to polar caps, from mountains and prairies to forests and coastlines, and our bodies serve as habitats for a profusion of, bacteria, protozoa, fungi, and viruses. Studying biology allows us to understand our place in the earth¢s environments, our unwitting hospitality to so many microorganisms, and our relationship to life forms here and perhaps elsewhere in the universe.
2. As conscious beings, we make daily choices about how to maintain our own life and health. Each of us decides what to eat; when and how much to sleep; how much and what types of exercise we need; whether or not to smoke, drink, or use birth control; and so on. A course in biology helps us understand the basic mechanisms and effects of eating, sleeping, exercising, smoking, and other common activities, and how to make the best choices for ourselves.
3. As finely tuned biological entities, we sometimes get out of balance and become ill. Biology focuses not only on normal life processes.
4. We live in an era of science and technology, with a constant stream of complex, sometimes confusing new developments modifying our lives in both large and small ways. Without a knowledge of biology, significant developments, such as gene splicing and genetic screening, would seem threatening rather than the positive tools they have already become for medicine, agriculture, and scientific research.
5. Finally, a solid background in life science is required for many careers, including work in the allied health professions, agriculture, food service, parks and recreation, and education. What¢s more, occupations with scientific and technological component will be increasingly available in the future.
This list shows how important biology is to a college student in today¢s world. And beyond all these reasons, it is simply a fascinating subject. Let¢s dig in and see.
Abridged from Biology by John H Postlethwait
(1400)
1.
c:
to relate, reproduce, confuse, threaten, maintain, focus,
reason (n), habitat, profusion, hospitality, activity, entity, stream, knowledge, research, career;
modern (a), fascinating, important, allied, significant, complex, constant, common.
2.
( ; ) .
1.They should work hard to understand it.
2. Biology is one of the most relevant subjects in a modern university.
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3. We humans are living mammals.
4. We live in a range of the earth¢s ecological zones.
5. This allows us to understand our place in the earth¢s environments.
6. We make daily choices about how to maintain our own life.
3.
:
surroundings, n; being, n; wonder v, important, a;rest n; large, a;
wood, n;
surprise, v; environments, n; big, a; significant, a; forest, n; recreation, n;
human, n; habitat, n.
4.
:
to relate,reproduce, require, include;
science (n) scientist; scientific, fungus, subject, virus, environment relationship, activity,choice, reason, recreation;
human (a), conscious;
5.
:
1. Why is Biology one of the most relevant subjects in a modern university?
2. Are we humans living mammals? If we are, prove it.
3. Do our bodies serve as habitats for a profusion of bacteria and viruses?
4. What era do we live in?
5. Does Biology help us to understand the basic mechanisms of eating, sleeping?
6. What does Biology focus on?
6.
:
Why do we studyBiology.
The importance of Biology for man.
Unit 2
:
irritability circulation
nutrition assimilation
digestion respiration
absorption excretion
environment reproduction
Important Life Functions
As we study more and more about plants and how they live, we shall see that all of them perform several functions in common. These are called life functions. One way of studying animals and plants is to begin with their life functions. It is a common mistake of young students to think of these processes as separate or distinct, when they are really very closely connected and dependent one on another. These life functions are: sensation(irritability), motion, food-taking, nutrition (digestion, absorption, circulation, assimilation), respiration, excretion, and reproduction.
Sensation (Irritability).- Animals react or are sensitive to heat, light and other outside influences which we call stimuli. This reaction or response of animals and plants and to stimuli is called sensation or irritability and is an important life process, for it enables them to act so as to profit from their surroundings. In other words, sensation enables animals and plants to adapt themselves to their environment.
Motion - All animals can move from place to place or move parts of their bodies. The higher animals move with ease as a result of highly developed muscular and nervous systems. Tiny plants move about in the water, and the leaves of many higher plants move toward the sunlight. Life movement then in animals and plants is not like the moving of the wind or of a flowing stream, purely physical motion, for a living thing has to supply from its own body the energy required for motion. Living things can change at will the direction and speed of their movements, but lifeless physical forces cannot. In biology motion is defined as the ability of living things to change their position without employing the force of the wind or gravity, or similar outside agencies.
Nutrition - Nutrition includes first the preparation of food so that the animal or plant may have it in the form of a solution (liquid).This is digestion. Next, the food must be taken into the veins of the animal or plant. This is absorption. Then the food must be carried to all parts of the animal or plant. This is circulation. And lastly, each part of the animal or plant must take from the blood or the sap the food that it needs. This is assimilation. Nutrition is the term under which are described the changes in food from the time it enters into solution until it becomes a part of the living body of an animal or plant.
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Respiration - All animals and plants require energy in order to live. When oxygen unites with some of the food in the protoplasm of the cells, energy in the form of heat is produced. Two waste products result-carbon dioxide and water. Respiration is the introduction of oxygen into the cells, the production of heat, and the giving off carbon dioxide.
Respiration, which takes place in every living cell, should not be confused with breathing. Only animals that have lungs can breathe. Breathing then is merely an adaptation to bring the oxygen of the air in contact with the blood vessels of the lungs. Animals and plants which do not have lungs, have other structures for admitting oxygen to the living cells.
Reproduction. - All kinds of animals and plants either produce young or become extinct. It is common knowledge that all living things grow old and eventually die, and if there were no provision for producing young, there would be no such thing as continuing life. While the bodies of animals and plants are young, nature gives them the means and instinct to produce more animals and plant like them. This has been the story since the beginning of life so far as science can determine, and it is, the only means by to which there can be any increase in the total number of living things. Reproduction, then, is the process by which life continues from generation to generation.
(3.200)
1.
:
to perform, connect, absorb, reproduce, respond, profit adapt oneself to, move, supply, define, employ, include, give off, confuse, admit;
sensation(n), nutrition, digestion, circulation, respiration, influence, surroundings, response, speed, ability, breathing;
sensitive ( a ), distinct, muscular, nervous, physical, lifeless, living.
2.
:
1. You can see the sea from our window.
2. I¢m afraid I can¢t come to your party next Friday.
3. When we went into the house, we could smell burning.
4. She is able to speak two foreign languages.
5. The fire spread through the building very quickly but everyone was able to escape.
6. I must write to Ann I haven¢t written her for ages.
7. He had to go to hospital yesterday.
8. She will have to do this work next week
3.
:
1. He will be able to tell you about it tomorrow.
2. You will be allowed to go there after your lessons.
3. He had to explain this grammar rule once more.
4. She has to stay at home.
5. He is able to speak Spanish.
4.
:
1. One way of studying animals and plants is to begin with their life functions.
2. This reaction of animals enables them to act so as to profit from their surroundings.
3. Movement in animals and plants is not like the moving of the wind or of a flowing stream.
4. Respiration, which takes place in every living cell, should not be confused with breathing.
5. Animals and plants which do not have lungs have other structures for admitting oxygen to the living cells.
5.
:
to connect, respond, unite, breathe, admit;
sensation (n), irritability, nutrition, digestion, absorption, circulation, assimilation, respiration, excretion, speed change, force solution blood, sap, oxygen, carbon dioxide;
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muscular(a).
6.
:
1. What are life functions?
2. Are they really closely connected with each other?
3. What do we call irritability?
4. Does sensation enable animals and plants to adapt themselves to their environment?
5. Why do the higher animals move with ease?
6. Can plants move?
7. What is respiration?
8. Why should not we confuse respiration with breathing?
7.
:
Important Life Functions
2 -
Unit 3
tissue
nucleus
cell
vacuole
thick
chlorophyll
cellulose
vital
cytoplasm
view
The Biology of Plant Life.
General Structure of Plants. - No matter how simple or how complex a plant may be, it can exist only if it carries on the several life processes. The higher plants, like animals, are made up of organs, such as the roots, stem, leaves, flowers, and usually the fruit. The organs of plants are made up of tissues, and the tissues are made up of cells. Cells vary greatly in size and shape even in the same tissue and even more so in different plants. The separate cells of a tiny plant, Pleurcoccus, are nearly spherical, and so small as to be invisible without the aid of a microscope. Others, like root hairs are very long and slender in shape and large enough to be seen by the naked eye.
The Three Parts of the Plant Cell. -All cells have three main parts. These are: (1) the wall. The wall in a plant cell is usually thicker and firmer than the wall in animal, because of the presence in plants of a substance known as cellulose, a carbohydrate. (2) The wall in every cell encloses a mass of cytoplasm, the second main part of a cell. In the cytoplasm is imbedded (3) the nucleus, the third main part of a cell.
The nucleus is darker than the surrounding cytoplasm. Besides the wall, the cytoplasm, and the nucleus, a plant cell usually contains spaces called vacuoles, filled with cell sap, and if the cell is green, it contains small green particles, called chlorophyll bodies or chloroplasts. In the plant as in the animal the cell is the unit of structure and of function of all living parts.
Protoplasm. - The entire cell is composed of protoplasm or substances made by it. This has one form in the wall, another in the cytoplasm, and still another in the nucleus. Cytoplasm is that particular kind of protoplasm which is surrounded by the cell wall. It is the agent that, for the most part, carries on the vital processes of the plant. The nucleus is still another kind of protoplastm which is very important in the life process of the cytoplasm, especially in reproduction.
Not all plants, however, are large, have green leaves, and produce food for man and animals as does the apple tree. The biology of plants or botany requires that we take a broader view of plants and how they live. In this richly varied world there are plants like trees, some of which are the largest living things, and small plants, thousands of which can live in a small drop of liquid; plants that are green and those that lack green color; helpful plants that man cultivates, and harmful ones that he tries to get rid of; plants that live only in water, and those that live only on land; plants that produce flowers and fruit, and others that do not; plants that live for hundreds of years and plants that live for only a few hours; plants that like abundance of sunshine, and those that prefer dim light.
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Green plants are so common that you may never have stopped to think how wonderful and important they are. A good way to begin our general study of plants is to compare them with animals. If you have ever tried to raise plants in the house or garden, you know that, like animals, they cannot live without water, air, food, light, and a moderate amount of heat. Like animals too they are of different shapes, sizes, and colors, and perform all the life processes in passing through the life cycle. In fact, the differences are not so many as the likenesses, although they are more apparent, for only three are important; namely, they are not conscious, they are unable to move about, and they make their own food, but they are the only food-makers in the world, a fact which gives them an importance which no other organisms have. In making food for themselves and animals, they also, incidentally, help animals in two other ways, as we shall see later.
Although we are familiar with green flowering plants in a general way, we should not think of them as the only plants that exist. In biology the apple tree and other flowering plants are considered highly specialized forms of plant life. Many plants do not produce flowers, nor even have roots, stems, or leaves. Such are the molds that grow on decaying fruit and bread, the bacteria that cause disease, the green scum that floats on ponds, and the mosses and mushrooms in the woods, to mention only a few.
(3.000)
1.
:
to carry, vary, exist, be made up of, enclose, fill with, be composed of, lack, get rid of, prefer, compare, consider, cause;
tissue (n), cell, no matter how, root hairs, aid, by the naked eye, cellulose, carbohydrate, cytoplasm, unit, nucleus (nuclei ), abundance, amount, bacterium(bacteria ). disease; moss;
complex(a), slender, tiny, separate, invisible, firm, main, moderate.
2.
:
nucleus, bacterium, phenomenon, species, stimulus, foot, goose, fungus,tooth, man, woman, crisis, mouse, wolf.
3.
:
1. What is the matter with him?
2. It made no matter to him that his brother lost all his money.
3. It does not matter if I miss my train, there is another one later.
4. It maters a good deal to me.
5. It's a matter of great concern to us.
6. No matter what he thinks I'll do it.
7. It's a matter of common knowledge.
8. No matter how simple or how complex a plant may be, it can exist only if it carries on the several life functions.
4.
(must, must not, had to, needn't, don't have to) :
1. A soldier... obey orders.
2. I think we... pay in advance.
3. Jane... go to school yesterday.
4. Passengers...... speak to the driver.
5. Saturday is my day off. I...... to work.
6. Students... leave bicycles in front of the library.
5.
:
to grow (grew, grown), vary, be made up of, enclose, be composed of, cause (v, n ), get rid of;
tissue (n), cell,by the nakedeye, amount, disease, moss,mushroom, sap;
no matter how, no matter what, besides.
6.
:
1. What are higher plants made up of?
2. What are the organs of plants composed of?
3. What are the three parts of the plants cell?
4. How do we call small green particles in the green cell?
5. What is cytoplasm?
6. In what life process is the nucleus very important?
7. How do plants differ in size?
8. Do all plants produce flowers?
7
:
1. General structure of plants.
2. The three parts of the plant cell.
3. Protoplasm.
4. Speak about flowering and non-flowering plants.
UNIT 5
:
Verterbrates
cenozoic
variety
scale
specimen
occur
fossilized
tough
turtle
era
Class Reptilia
The Rise of Animal Life. At present reptiles are not so widely distributed as other vertebrates - fishes, birds, or mammals. They are seldom found in cold regions, are not numerous in temperate climates. They flourish in tropical conditions. However, there was a time, long, long ago, when this group dominated animal life, both in variety and distribution.
Some of the fossilized specimens which have been discovered and analyzed prove that the animal world has been developing continually. Lots of animals have vanished from the face of the Earth, some becoming extinct and others more highly developed. Similar transformations are known to have occurred in plants.
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The most important stages in the development of life on Earth are measured in separate eras: most ancient era; the Paleozoic; the Mesozoic Era; and the Cenozoic Era (the most recent).
Early Reptiles. Fossil remains of early vertebrates have been discovered in strata dating back to the Paleozoic Era. Fishes appeared first, and were followed by amphibians. Towards the close of the Paleozoic Era the climate of many regions in the world, which was hot and damp, must have become drier. Those conditions proved unfavourable to the amphibians with their scaleless, moist skins. Some adapted themselves by developing a horny skin, and continued living on land.
The new environment gave rise to a chain of other adaptations: the lungs developed until they were able to meet the oxygen requirements of the organism; there were notable advances in the brain; the animals learnt to reproduce in the absence of water by laying large eggs enclosed in hard shells or tough skins. Thus the early amphibians developed into early reptiles (stem reptiles).
Variety of Form. The reptiles reached their peak in the Mesozoic Era, when the birds and mammals were few and unimportant. That is why the era is called the Age of Reptiles.
A great number of skeletons of extinct reptiles are being discovered in the Mesozoic strata. Some bear a distinct resemblance to modern turtles, lizards, and crocodiles. Others look very different.
Among the walking land vertebrates were the Dinosauria (monster reptiles). Some were really huge.
Extinction. Why did these reptiles become extinct, giving way to others?
One of the factors was the change in the climate which grew much cooler at the close of the Mesozoic Era. The new conditions were most unfavourable for the reptiles, whose body temperature had never been stable. Many proved unable to withstand the change, and died.
(2.000)
1.
:
to withstand, become extinct, measure (n, v);
rise (n),temperature, distribution,specimen, chain of other adaptations, requirements, shell, resemblance;
scaleless (a), notable, stable.
2.
