HOW DOES THE BIOLOGICAL CLOCK TICK?
A Our life span is restricted. Everyone accepts this as ‘biologically’ obvious. ‘Nothing lives for ever!’ However, in this statement we think of artificially produced, technical objects, products which are subjected to natural wear and tear during use. This leads to the result that at some time or other the object stops working and is unusable (‘death’ in the biological sense). But are the wear and tear and loss of function of technical objects and the death of living organisms really similar or comparable?
B Our ‘dead’ products are ‘static’, closed systems. It is always the basic material which constitutes the object and which, in the natural course of things, is worn down and becomes ‘older’. Ageing in this case must occur according to the laws of physical chemistry and of thermodynamics. Although the same law holds for a living organism, the result of this law is not inexorable in the same way. At least as long as a biological system has the ability to renew itself it could actually become older without ageing; an organism is an open, dynamic system through which new material continuously flows. Destruction of old material and formation of new material are thus in permanent dynamic equilibrium. The material of which the organism is formed changes continuously. Thus our bodies continuously exchange old substance for new, just like a spring which more or less maintains its form and movement, but in which the water molecules are always different.
C Thus ageing and death should not be seen as inevitable, particularly as the organism possesses many mechanisms for repair. It is not, in principle, necessary for a biological system to age and die. Nevertheless, a restricted life span, ageing, and then death are basic characteristics of life. The reason for this is easy to recognise: in nature, the existent organisms either adapt or are regularly replaced by new types. Because of changes in the genetic material (mutations) these have new characteristics and in the course of their individual lives they are tested for optimal or better adaptation to the environmental conditions. Immortality would disturb this system – it needs room for new and better life. This is the basic problem of evolution.
D Every organism has a life span which is highly characteristic. There are striking differences in life span between different species, but within one species the parameter is relatively constant. For example, the average duration of human life has hardly changed in thousands of years. Although more and more people attain an advanced age as a result of developments in medical care and better nutrition, the characteristic upper limit for most remains 80 years. A further argument against the simple wear and tear theory is the observation that the time within which organisms age lies between a few days (even a few hours for unicellular organisms) and several thousand years, as with mammoth trees.
E If a life span is a genetically determined biological characteristic, it is logically necessary to propose the existence of an internal clock, which in some way measures and controls the ageing process and which finally determines death as the last step in a fixed programme. Like the life span, the metabolic rate has for different organisms a fixed mathematical relationship to the body mass. In comparison to the life span this relationship is ‘inverted’: the larger the organism the lower its metabolic rate. Again this relationship is valid not only for birds, but also, similarly on average within the systematic unit, for all other organisms (plants, animals, unicellular organisms).
F Animals which behave ‘frugally’ with energy become particularly old, for example, crocodiles and tortoises. Parrots and birds of prey are often held chained up. Thus they are not able to ‘experience life’ and so they attain a high life span in captivity. Animals which save energy by hibernation or lethargy (e.g. bats or hedgehogs) live much longer than those which are always active. The metabolic rate of mice can be reduced by a very low consumption of food (hunger diet). They then may live twice as long as their well fed comrades. Women become distinctly (about 10 per cent) older than men. If you examine the metabolic rates of the two sexes you establish that the higher male metabolic rate roughly accounts for the lower male life span. That means that they live life ‘energetically’ – more intensively, but not for as long.
G It follows from the above that sparing use of energy reserves should tend to extend life. Extreme high performance sports may lead to optimal cardiovascular performance, but they quite certainly do not prolong life. Relaxation lowers metabolic rate, as does adequate sleep and in general an equable and balanced personality. Each of us can develop his or her own ‘energy saving programme’ with a little self-observation, critical self-control and, above all, logical consistency. Experience will show that to live in this way not only increases the life span but is also very healthy. This final aspect should not be forgotten.
- Giải thích từ vựng
- Life span (n) /ˈlaɪf.spæn/ tuổi thọ, khoảng thời gian sống
Eg: The average human life span in the developed countries has increased over the last hundred years.
- Restricted (a) /rɪˈstrɪk.tɪd/ giới hạn, hạn chế
Eg: Job opportunities are severely restricted at the moment.
Collocation
- Restricted goods/service/supply
- Restricted to sb/sth
- Wear and tear (n) /ˌweər ən ˈteər/ sự hao mòn, mất chất lượng (hư tổn xảy ra một cách tự nhiên và không thể tránh khỏi khi một vật gì đó được sử dụng và bị cũ đi)
Eg: Seat covers on buses take a lot of wear and tear.
Collocation
- General/normal wear and tear the airline will not accept liability for minor damage to the outside of luggage caused by normal wear and tear.
- Wear and tear on sth the fuel additive reduces wear and tear on car engines.
- Constitute (v) /ˈkɒn.stɪ.tʃuːt/ cấu tạo, tạo thành
Eg: The long-term unemployed now constitute a sort of underclass.
The publishers claim that the book constitutes ‘the first sequential exposition of events and thus of the history of the revolution’.
- Age (v) /eɪdʒ/ già đi, lão hóa
Eg: Sunbathing can prematurely age and wrinkle the skin.
The death of his wife had aged him greatly.
- Inexorable (a) /ɪˈnek.sər.ə.bəl/ không lay chuyển được, không động tâm, không mủi lòng
Eg: Aging is an inexorable process.
- Permanent (a) /ˈpɜː.mə.nənt/ lâu dài, lâu bền, vĩnh cửu
Eg: The accident left him with permanent brain damage.
Mont blanc has a permanent snow cap.
- Equilibrium (n) /ˌek.wɪˈlɪb.ri.əm/ sự thăng bằng
Eg: The disease destroys much of the inner ear, disturbing the animal’s equilibrium.
He devised a mathematical method to prove the existence of equilibrium among prices, production, and consumer demand.
- In principle: trên nguyên tắc/ nói chung (không đi vào chi tiết)
Eg: In principle I agree with the idea, but in practice it’s not always possible.
They have agreed to the proposal in principle but we still have to negotiate the terms.
They have approved the changes in principle.
- Possess (v) /pəˈzes/ có, chiếm hữu, sở hữu
Eg: We’re trying to bring out the artistic talents that many people possess without realizing it.
Ruth possessed great writing skills.
- Mechanism (n) /ˈmek.ə.nɪ.zəm/ cơ chế
Eg: These automatic cameras have a special focusing mechanism.
She’s actually kind of insecure, and her rudeness is just a defence mechanism.
- Optimal (a) /ˈɒp.tɪ.məl/ tốt nhất, tối ưu
Eg: Companies benefit from the optimal use of their resources and personnel.
- Immortality (n) /ˌɪm.ɔːˈtæl.ə.ti/ tính bất tử, tính bất diệt, tính bất hủ, sự sống mãi
Eg: Many americans believe in some kind of immortality of the soul.
The paintings feature men eating magical plants to achieve immortality.
- Evolution (n) /ˌiː.vəˈluː.ʃən/ sự tiến hoá, sự phát triển
Eg: We watched a documentary about the story of human evolution over the last three million years.
- Parameter (n) /pəˈræm.ɪ.tər/ thông số, tham số, tham biến
Eg: The researchers must keep within the parameters of the experiment.
Collocation
- Within the parameters of sth we must work within the parameters of the law.
- Parameters for/around sth the parameters for establishing the fund are vague.
- Broad/clear/general paramaters policies create clear parameters and make it easier to manage everyday business life.
- Define/establish/set parameters it is important to set paramaters for working hours that are reasonably flexible.
- Performance/price/risk parameters the company has been asked to explain the performance parameters of their scheme.
- Constant (a) /ˈkɒn.stənt/ bất biến, không thay đổi
Eg: We ran at a fairly constant speed.
Một số từ đồng nghĩa:
- The same you look exactly the same as you did ten years ago!
- Same old same old the italian restaurant is under new management, but it’s just the same old same old.
- Unchanging his novel is about the unchanging nature of humanity.
- Unchangeable the company’s position on the matter is absolute and unchangeable.
- Duration (n) /djʊəˈreɪ.ʃən/ thời gian, khoảng thời gian (tồn tại của một sự việc)
Eg: He planned a stay of two years’ duration.
Does the rate only apply for a limited period or for the duration of the loan?
The overall duration of the flight was 11 hours.
- Advanced (a) /ədˈvɑːnst/ tiên tiến, tiến bộ, nâng cao
Eg: The corpse was in an advanced stage of decomposition.
Passing a written exam is a prerequisite for taking the advanced course.
- Hold sth up (phrasal verb) trì hoãn, giữ lại
Eg: The documents were held up in the post, so the sale was delayed.
- Captivity (n) /kæpˈtɪv·ɪ·t̬i/ tình trạng bị giam cầm, tình trạng bị câu thúc
Eg: Most animals bred in captivity would probably not survive in the wild.
He was held in captivity for three years.
- Hibernation (n) /ˌhɑɪ·bərˈneɪ·ʃən/ sự ngủ đông (động vật)
Eg: The survey depends on looking for eaten hazelnuts – an important food source which enable dormice to put on weight for winter hibernation.
- Lethargy (n)/ˈleθ·ər·dʒi/ trạng thái hôn mê; giấc ngủ lịm
Eg: He felt that he had to drag himself out of his lethargy and begin to write.
They will need to shake off their lethargy if they want to win the game.
- Comrade (n) /ˈkɒm.reɪd/ bạn, đồng chí
Eg: Many of his comrades were killed in the battle.
- Distinctly (adv) /dɪˈstɪŋkt.li/ rõ ràng, rành mạch, minh bạch, rõ rệt
Eg: The groups sang in distinctly different performing spaces.
There’s something distinctly odd about her.
- Account for (phrasal verb) giải thích
Eg: Rural americans are often older than those in other parts of america and that may account for the slower adoption rates for internet access.
- Sparing (a) /ˈspeə.rɪŋ/ dè xẻn, tiết kiệm
Eg: Be sparing with the butter as there isn’t much left.
- Reserve (n) /rɪˈzɜːv/ đồ dự trữ
Eg: She keeps a little money in reserve.
- Extend (v) /ɪkˈstend/ kéo dài (thời hạn…), gia hạn, mở rộng
Eg: We have plans to extend our house.
- Cardiovascular (a) /ˌkɑː.di.əʊˈvæs.kjə.lər/ thuộc hệ tuần hoàn, thuộc tim mạch
Eg: Cardiovascular disease is a class of diseases that involve the heart or blood vessels.
- Equable (a) /ˈek.wə.bəl/ không thay đổi, đều
Eg: Graham has a fairly equable temperament – i haven’t often seen him really angry.
- Prolong (v) /prəˈlɒŋ/ kéo dài; nối dài; gia hạn
Eg: We were having such a good time that we decided to prolong our stay by another week.
- Stable (a) /ˈsteɪ.bəl/ vững vàng; ổn định, bền
Eg: House prices have been reasonably stable these past few years.
I’m just happy to see him in a stable relationship.
- Consumption (n) /kənˈsʌmp.ʃən/ sự tiêu thụ, sự tiêu dùng (hàng hoá, điện, than, nước…)
Eg: The meat was clearly unfit for human consumption.
These products are not for national consumption, but for export.
- In accordance with: tuân thủ, tuân theo hoặc nghe theo một mong muốn, điều luật, một luật lệ.
Eg: In accordance with her wishes, she was buried in france.
The council has not acted in accordance with its obligations.
- Mutation (n) /mjuːˈteɪ.ʃən/ (sinh vật học) đột biến, sự thay đổi, sự biến đổi
Eg: Environmental pressures encourage genes with certain mutations to persist and others to die out.
These plants carry the mutation for red flowers.
- Luyện tập
Bài 1: Chọn từ trong khung để hoàn thành các câu bên dưới
| restricted | inexorable | possessing | lifespan | ageing |
| constitutes | equilibrium | In principle | wear and tear | permanent |
- Worms have a ……………………..…of a few months.
- Engineering work will also mean ……………………services between London and the Midlands
- The insurer will reduce any payout to take into account ………………………of the item.
- The takeover of the embassy ……………………..a blatant violation of international law.
- A great deal of research has examined the effects of ……………….on our physical and mental capacities.
- When would it end its …………………political advance?
- Our office is in a ……………………state of chaos.
- Any disturbance to the body’s state of …………………can produce stress
- ……..…………..there is nothing that a human can do that a machine might not be able to do one day.
- He was charged with ………………….a fake passport.
Bài 2: Chọn đáp án đúng để điền vào chỗ trống.
- The elevator has a safety …………………………..which prevents it from falling. A. mechanism B. duration
- This product was an extremely significant step in the …………………of computer games. A. captivity B. evolution
- We have found that our workers reach their ……………………level of performance around 11 a.m. A. optimal B. advanced
- He sees cloning as the first step to achieving…………………… A. equilibrium B. immortality
- The report defines the ……………………….of best practice at a strategic, operational, and process level within an organization. A. parameters B. lethargies
- She was tortured many times during her……………………………… A. reserve B. captivity
- Check to make sure your oven maintains a …………………..temperature. A. constant B. optimal
- Taking antibiotics will shorten the ………………………..of the illness. A. hibernation B. duration
- The problems with the new system would …………………….the project. A. hold up B. extend
- Twenty thousand visas have been allocated for immigrants who earn …………. academic degrees. A. advanced B. inexorable
- Internet chat rooms and messages are ………………………..separate media. A. equably B. distinctly
- ………………………is an adaptation to a seasonal shortage of food, low environmental temperatures, and snow cover on the ground. A. Hibernation B. immortality
- The report criticizes the ……………………….shown by employers when it comes to job creation. A. immortality B. lethargy
- The poor weather may have ……………………… for the small crowd. A. accounted B. prolonged
- Doctors now advise only ………………………use of such creams. A. advanced B. sparin
- She chewed each delicious mouthful as slowly as she could, …………………..the pleasure A. sparing B. prolonging
- On the point of maintaining an …………………..climate in the countryside, no one wishes that more than myself. A. equable B. stable
- The implications of such findings is that by changing the communication patterns between spouses, the rate of …………………………………….diseases could perhaps be reduced. A. cardiovascular B. constant
- I know my opinion is shared by many of my…………….in the Labour movement. A. comrades B. reserves
- The librarian has put the book on ……………………….for me. A. reserve B. hibernation
- The government has produced a series of leaflets designed to …………………. public awareness of the dangers of AIDS. A. prolong B. extend
- He’s been taken to hospital where his condition is described as serious but ……………A. stable B. cardiovascular
- The commonest cause of cirrhosis is alcohol ……………………. A. comrade B. consumption
- In …………………… with her wish, her wedding will be set up on the coast with a variety of flowers from the light pink of lotus to the striking of roses A. accordance B. consumption
- These cells have been affected by………………………… A. mutation B. consumption
- LUYỆN TẬP
Bài 1:
1.lifespan 2. restricted 3. wear and tear 4. constitutes 5.ageing
- inexorable 7. permanent 8. equilibrium 9. In principle 10. possessing
Bài 2:
- A 2. B 3. A 4. B 5.A
- B 7. A 8. B 9. A 10.A
- B 12. A 13. B 14. A 15.B
- B 17. A 18.A 19. A 20. A
- B 22. A 23. B 24.A 25.A
