【BIO】談Bio嚴謹嘅答題要求

唔知道修Bio的同學有無發覺，Bio卷答題要求其實比其他科麻煩。以下會為大家分析幾個常見現象，然後逐一拆解！

By: Yuen Lung

唔知道修Bio的同學有無發覺，Bio卷答題要求其實比其他科麻煩。以下為常見現象:

佔1分的point暗藏2-3個points或keywords
4-5分呢分多嘅題目答案無overflow。5分可以得5個points可以寫，較少/無其他答案
明明個答案正確，但因為表達問題而被扣分
唔知條題目想人答A定B，因為兩個答法都合理

等我試下逐一拆解。

1 我鬼知一個point要寫咁多嘢？

其實通常睇完答案先會知：( 呢D係經驗黎的。睇睇呢條題目：Why does the rate of heart beat increase when we do exercise?

答案 A: It is to increase blood supply to the body.

答案 B: It is to increase blood supply to muscles.

答案 C: It is to increase oxygen supply to muscle cells.

答案 D: It is to increase oxygen and glucose supply to muscle cells for their respiration.

答案 E: This can increase blood flow to muscle cells, and in turn increase the oxygen and glucose supply for them to carry out respiration to give more energy for muscle contraction.

答案 E 係咪好冗長呢？正常黎講，一個point唔會要求你答咁多嘢，如果唔係真係太離譜。但問題係，究竟邊D先算重點？邊D係題目必定要你提及的概念？邊D係上頭想你寫的keywords？由於我懶得估出卷人想要咩嘢，我傾向好似答案E 咁大包圍。無論呢條題目佔1分定2分，我都咁答。

前提：熟書&Marking+字速快

一開頭拿不到分是正常的。記住呢D經驗，慢慢你會睇得出唔同題目需要包咩元素.

2 點解佢一定要我寫呢幾個points，明明可能有幾種推論，4-5分題點解可以無overflow 咁harsh?????

不如問下考評局...無得問啦，唯有默默接受，分析Marking。4-5分題有兩種：第一種係Standard/Typical Questions，例如
"How does geographical isolation result in speciation? From the pedigree, deduce whether the disease allele is dominant or recessive. How does vaccination brings us immunity to a certain type of virus? How does base mutation lead to the production of a certain type of dysfunctional protein? "
呢D題目其實有既定答法，在歷屆pastpaper或普通練習都成日出，答黎答去都係個D points，只不過要將字眼改一改套翻落條題目。

第二種係Atypical Questions，要你面對一個唔熟的情境，嘗試解釋或推論現象。呢個就麻煩喇！

首先你要嘗試估下條題目究竟係要靠估(sad)，定係可以用翻平時答開嘅嘢。

舉個例子，2014DSE有一條要你解釋一個假說：

古時嘅狼可能被早期人類聚居處附近的垃圾堆吸引，並進食人類的廚餘，因而在馴化過程中被選上多個製造amylase嘅gene copies，類似咁嘅物體。

如果你眼精，可以睇得出同 Evolution 有關。Identify到牽涉嘅Topics之後，就睇頭睇尾砌中間。題目間接問你 A&B 有咩關係，換句話講係A點樣導致B。所以A係頭B係尾。B的上一步是什麼/A的下一步是什麼？靠咁樣想去砌一個答案。呢個方法係我老師教的。

B翻轉頭推論:

Wolves with more copies of the gene are selected => Why is having more copies advantageous? => They can produce more amylase and digest starch into maltose more effectively. => Absorb sufficient nutrients to survive and reproduce.=> Why do they need to digest starch in particular? There can be other nutrients? => Environmental condition: domestic waste contains rich starch (factor that lead to natural selection) => How do they increase the copies of the gene over generations by natural selection? => Originally, the number of copies of the gene varied across individuals.

A去翻後推論:

Variations in the number of copies of the gene for amylase production exist among the wolves. => Natural selection acts on the wolves as they were attracted to domestic waste. => human waste contains relatively rich starch => Those with more copies of the gene can produce more amylase to digest starch into maltose more effectively and absorb more sugars => Wolves with more copies of the gene are therefore more able to surviveand reproduce.=> Proportion of wolves with more copies of the gene incre (On the other hand, those with fewer copies are eliminated more easily.)

到頭來都係用翻識嘅嘢。（Genetic variations/Natural selection / Adaptability / Proportion 等答題方向係非常standard）

至於要估嘅題目，就係好似2016 Rocky Shore Crab個條：

"The two species coexist on a rocky shore and feed on the same species of alga. When the two crab species are kept in a simulated habitat with the algal species, they will fight against each other. According to the information given in the diagram, deduce which crab species, A or B, would be a stronger competitor. (請參閱pastpaper)"

從兩個Crab species嘅居住環境估佢地嘅生存能力，再推論佢擺埋一齊邊個會鬥贏。呢條好明顯平時Exercise唔會Cover到。呢D題目都可以用AB推論，你可能只推論到一步，但1-2分已經好好。無咩人會知考評局想點。

呢個推論方法適合應用係一D多Steps嘅答題度。寫答案之前可以先畫個flow chart，提自己要答咩points。

3 我答啱你又嫌我表達唔清晰，考緊英文啊???

係。Bio就係考你表達夠唔夠precise & specific。有時好minor嘅mistakes或者表達變化，可以令人曲解你嘅答案。

基礎錯誤例子一： A, B, C, lead to D, E, F. 究竟係ABC一齊導致DEF，定ABC分別導致DEF？

基礎錯誤例子二： X decreases with Y =/= X decreases when Y decreases.

X decreases with Y == X decreases when Y increases (vice versa)

相信日校老師都有講過呢類白痴錯誤。至於比較高階嘅錯誤，就難在課堂Cover曬，可能要錯過先知。

高階錯誤例子一： 答案唔夠精密

Why can we develop strong immunity against Disease X (caused by bacteria) if we are vaccinated beforehand?

答案A: Vaccines contain antigens of the bacteria causing Disease X. These antigens stimulate B cells to multiply and differentiate into memory cells. These memory cells memorize the bacteria. When bacteria of Disease X enter our body again, the memory cells recognize them and differentiate into plasma cells to produce large amount of antibodies rapidly to kill the bacteria.

答案B: Vaccines contain antigens of the bacteria causing Disease X. These antigens stimulate the B cells to multiply and differentiate into memory cells specific to the antigens. These memory cells memorize the specific antigens. When bacteria having these specific antigens enter our body, the memory cells can quickly differentiate into plasma cells, which produce large amount of antibodies specific to the antigens of bacteria rapidly to kill them.

表達上嘅少量改變，可能足以影響Marker judge 你有無misconceptions。你應該會留意到答案A無好似答案B咁提及Specificity，而且答案A無講明memorize & recognize嘅嘢其實係bacteria 上嘅antigens。要知道secondary response 唔係因為同一種bacteria入侵，而係因為有同樣嘅 antigens 進入體內(同一種bacteria可以有唔同antigens)。另外，由於題目有”strong”呢隻字，所以我特意提及”quickly”，”large amount”，”rapidly“ 去highlight secondary response 效果強，盡量扣題（就算無strong呢隻字我可能都會寫咁多）。

4 條題目想我答咩？講清楚D會死？

多數情況下，出卷部門應該會確保題目無歧義，但係有D嘢真係憑感覺同經驗先知答咩。

例子： Why do our pupils constrict when there is strong light?

答案A: When strong light enters our eyes, the radial muscles of iris relaxes while the circular muscles of iris contracts. Therefore, our pupils constrict.

答案B: To prevent overstimulation of photoreceptors that potentially kill them. This protect the retina, and in turn our eyes.

邊個答案先啱呢？我認為大部分情況下係要答B，當然你要考慮埋題目背景。如果題目想你答A，其實佢可以問”How does strong light lead to constriction of pupils?” 咁你就要答個Biological process喇。否則，大部分情況都係答Purpose/Function etc.

結語

以上技巧同知識差唔多全部都係源於我嘅Bio老師，我一直受佢啟蒙。希望呢篇文可以解答各位嘅疑難。最後，由於能力所限，我唔能夠確定此文百分百準確無誤，切勿盡信。下次同大家講講我Chem嘅讀書心得。