中三問題

 

1.      According to the above characteristics, do you think a car(or robot) is a living thing? State your reasons.

回答這題目時審視一輛車子(或機械人)有否符合這些生命的特徵，留意，審視時應查看是否完成了這些特徵的過程。

車子(或機械人)

繁殖: 車子(機械人)不能自行產生新的車子，因此不能繁殖。但將來機械人可否懂得自行製造另一個與自身相同的機械人便是將來的可能性。

生長: 車子(或機械人)不會愈變愈大及變得愈來複雜，因此也沒有生長。

但

營養: 車子(或機械人)需要獲取物質(即食物)，產生能量使車子能活動，因此是有營養作用的。

呼吸: 車子(或機械人)可分解物質(燃料等)產生能量，因此有呼吸作用。

運動: 很明顯車子(或機械人)是能移動的。

感應: 車子(或機械人)安裝了許多不同的感應器，偵測外來或內部環境，尤其是一些自動駕駛的車子更明顯。

排泄: 車子(或機械人)機件內都會進行一些化學反應(尤其使用燃料的)，會產生不同的廢物，這些廢物會被排出車子外。

總括而言，車子(或機械人)沒有生殖及生長。但有營養、呼吸、運動、感應及排泄。如果我們把生長及生殖視作生命最重要的兩項特徵，那車子(或機械人)便不算生物。

Reproduction: Vehicles (robots) cannot produce new vehicles on their own, so they cannot reproduce.

Growth: Cars (or robots) don't get bigger and more complex, and therefore don't grow.

Nutrition: The car (or robot) needs substances (i.e. food) to generate energy to enable the car to move.

Respiration: Cars (or robots) can decompose substances (fuel, etc.) to generate energy, so they have respiration.

Movement: Obviously the car (or robot) can move.

Irritability: The car (or robot) is equipped with many different sensors to detect the external or internal environment.

Excretion: There will be some chemical reactions (especially those that use fuel) in the car (or robot), which will produce different wastes, and these wastes will be discharged out of the car.

All in all, a car (or robot) does not reproduce and grow. But they have nutrition, respiration, movement, irritability and excretion. If we consider growth and reproduction as the two most important characteristics of life, then a car (or robot) is not a living thing.

 

2.      Whether virus (e.g. Covid 19 virus) belongs to a living thing is a controversial issue among biologists. State the reason(s).

要回答這題目，首先要大概知道病毒是怎樣的。病毒的構造跟一般生物不同，沒有細胞膜。外層是蛋白質，一般生物的細胞不是。但有共通的物質，都是用核酸來作為遺傳訊息的。但病毒用的是DNA或RNA，而其他細胞用的祗是DNA。

病毒在寄主細胞外是沒有任何代謝反應的，沒有任何一項生命特徵。但病毒接觸到寄主細胞表面時，病毒會把遺傳物質送至寄主細胞內，利用寄主細胞的物質及代謝反應，複製遺傳物質，並產生大量相同的病毒，可視作有繁殖這特徵。但病毒構造太簡單，基本上不需要生長，形成新病毒後便破壞寄主細胞，再而感染附近的細胞或隨血液(或體液)流至其他位置，感染其他細胞。

病毒具爭論性，因為

(1)   很明顯有繁殖作用，但祇限於寄主細胞內。

(2)   但在寄主細胞外，則又明顯沒有任何生命特徵。

To answer this question, we must first know what a virus is. The structure of viruses is different from that of ordinary organisms, and virus has no cell membrane. The outer layer is made up of protein, the cells of ordinary organisms are not. But there is a common material , both use nucleic acid as genetic information. But viruses use either DNA or RNA, while other cells use only DNA.

 

The virus does not have any metabolic reaction outside the host cell, and does not have any living characteristics. However, when the virus contacts the surface of the host cell, the virus will transfer the genetic material to the host cell, and use the materials and metabolic reactions of the host cell to replicate the genetic material and produce a large number of identical viruses, which can be regarded as having the characteristics of reproduction. However, the structure of the virus is too simple and basically does not need to grow. After forming a new virus, it destroys the host cell, and then infects the nearby cells or moves to other locations via blood (or body fluid) to infect other cells.

 

Whether virus belongs to a living thins controversial because

(1) Virus can reproduce, but only in host cells.

(2) Outside the host cell, there is obviously no any signs of life, without any living characteristics.