2025年5月22日星期四

Advanced Questions Test-2025-05-20

 

S3 Advanced Questions Test

Date: 2025-05-20

Class: _________(    )              Name: ________________

Answer the following questions:

1.      If a person on a diet only drinks vegetable soup for a week and does not consume the soup ingredients, what problems might this person have? Why?

Background Knowledge

(1) What is the difference between the components of vegetable soup and its solid ingredients? 

   (2) How do these differences affect the human body? 

   ANS:

**Answer:** The nutrients in vegetable soup come entirely from the ingredients. The soup contains more water-soluble nutrients and some partially digested food substances, but the overall concentration is lower than in the solid ingredients, especially for components that are insoluble in water. 

   Therefore, drinking only the broth will result in reduced nutrient absorption, particularly of major macronutrients such as carbohydrates, proteins, and fats. 

2.      What type of food substances are mainly present in milk?

**Background knowledge:** What nutrients does milk contain? What are their approximate proportions? Apart from dietary fiber, milk contains all essential nutrients required by the human body. Among these six types of nutrients, water makes up the largest proportion, at least over 90%. 

**Answer:**

Milk primarily contains water (~90%), carbohydrates (lactose, ~4-5%), proteins (casein and whey, ~3-4%), fats (~3-4%), as well as minerals (e.g., calcium) and vitamins (e.g., vitamin D, B12). 

3.      Compared to other foods, what is the greatest advantage of milk?

**Background knowledge:** What nutrients does milk contain?

  **Answer:**

The biggest advantage of milk is its **complete nutrition**—it contains all essential nutrients (except dietary fiber) in a balanced ratio, is easily digestible, and is particularly rich in calcium and high-quality protein. 

  1. Skeletal muscles store glycogen. What are the benefits of this for organisms? For which kinds of exercise is this more advantageous? Explain briefly.

  **Background knowledge:** What is the function of glycogen? What is the function of skeletal muscles? Which types of exercise are most affected by glycogen's role? 

   **Answer:**

Glycogen stored in skeletal muscles provides quick energy, benefiting high-intensity or short-duration exercises (e.g., sprinting, weightlifting) by preventing fatigue due to low blood sugar. 

  1. During weight loss, performing a lot of weight-bearing exercises may cause weight to increase instead of decrease. Explain.

**Background knowledge:** What effects does weight training have on the body? What causes weight gain from exercise? What is the difference in mass between the lost and gained substances? 

 **Answer:**

 Weight training increases muscle mass (which is denser than fat). Even if fat decreases, muscle growth may lead to a higher overall weight, though the body becomes leaner. 

  1. Can sports drinks (e.g., Pocari Sweat) provide energy? Explain.

**Background knowledge:** What substances do sports drinks contain? Which nutrients provide energy? 

   **Answer:**

Yes. Sports drinks contain sugars (e.g., glucose), a type of carbohydrate that can be quickly broken down for energy, making them suitable for replenishment after prolonged exercise. 

  1. What types of exercise are not suitable for people with anemia?

   **Background knowledge:** What are the effects of anemia? What factors cause these effects? Which types of exercise are most affected by these factors? 

   **Answer:**

Anemia patients should avoid endurance exercises (e.g., long-distance running) because insufficient hemoglobin reduces oxygen delivery, worsening fatigue and dizziness. 

8.      Can consuming foods rich in collagen help keep the skin beautiful?

   **Background knowledge:** What is collagen? How does it differ from other proteins? What factors contribute to skin beauty? How is collagen absorbed by the body? 

   **Answer:**

No direct effect. Collagen is broken down into amino acids during digestion and must be resynthesized. Skin health also depends on vitamins (e.g., C, E) and other factors. 

  1. When sick, what type of carbohydrates are easiest for energy acquisition? Why?

  **Background knowledge:** What are the categories of carbohydrates? Which type is most easily absorbed? How does illness affect absorption? 

   **Answer:**

 Simple sugars (e.g., glucose) or disaccharides (e.g., sucrose), as their simple structure requires minimal digestion, making them ideal for quick energy during illness. 

  1. Why are fish with higher fat content more likely to contain vitamin D?

**Background knowledge:** What are the properties of vitamin D? How do these properties relate to its storage in the body? 

    **Answer:**

Vitamin D is fat-soluble and stored in fat tissue. Fatty fish (e.g., salmon) accumulate more vitamin D in their fat reserves compared to lean fish.

2025年5月12日星期一

糖尿病患者進行劇烈運動時會因血糖不足而暈眩?

糖尿病患者進行劇烈運動時會因血糖不足而暈眩?

背景問題:

1.      糖尿病患者的血糖量不是較一般人高的嗎?

2.      進行劇烈運動時,所有人血液內的血糖水平會有甚麼變化?

3.      正常人如何調節回正常的血糖量?

4.      為何糖尿病患者不能調節回正常的血糖量? (即正常人能正常調節到的,糖尿病患者哪方面做不到?)

 

建議答案(根據以上的提問)

1.      進行劇烈運動時,肌肉會消耗大量葡萄糖進行呼吸作用釋出能量供肌肉收縮之用,因此血液內的葡萄糖水平會下降。

2.      正常人體內胰臟探測到血糖水平下降時,會釋出更多高血糖素(一定要寫更多!)至血液。

3.      高血糖素會刺激肝臟及骨骼肌把貯存的糖原轉成葡萄糖,釋出至血液中,提升血糖水平。

哪糖尿病者以上哪一方面做不到? (無法釋出更多高血糖素抑或沒足夠糖原轉換?)

4.      糠尿病患者由於無法分泌胰島素(I型糖尿病患者)或體內對胰島素敏感度下降(II型糖尿病患者),因此無法有效把葡萄糖轉換成糖原貯存,導致體內 貯存的糖原較正常人低。

5.      進行劇烈運動時,葡萄糖被消耗後便無法及時補充,導致血糖不足而暈眩。


 引申問題: (可使用AI查問,但應先自己想一想答案,AI是用來參考的)

1.      正常人進行超長時間劇烈運動後也會出現血糖不足而暈眩嗎?

2.      瘦的人更易做劇烈運動時血糖不足嗎?

3.      糖尿病患者做運動時於前段時間會否因體內血液葡萄糖較高而有優勢?

4.      糖尿病患者可以是優秀的短跑運動員嗎?

5.      其他….


2025年4月25日星期五

物理式消化

 

ANS: 草食性動物的臼齒表面積較大及濶大,且凹凸不平,可更有效磨碎較堅韌的植物纖維。

      有些可能沒有犬齒,因為不需要用來咬緊獵物,也可提供更多空間貯存植物性食物。

 

ANS: 臼齒或前臼齒,因為這兩種牙齒表面的面積較大,用以咬斷堅硬的食物,例如骨骼,臼齒等不容易碎裂。

ANS: 蛀牙指的是牙齒表面有孔洞而已。除非蛀牙深入至髓腔,才會引致痛楚,因為髓腔內才有感痛的神經纖維。

ANS: 一定是化學式消化。因為祇有化學式消化才能把食物消化成身體可吸收的形式。而物理式消化不能。即使沒有進行物理式消化,食物還是可以消化成可吸收形式的。

ANS: 草食性動物。因為草食性動物的食物,即草類的植物纖維較肉類更易磨損牙齒的表面,因此需要不停生長,補充已磨損的部份,否則草食性動物很快便無法再進食。

餐後刷牙

減少進食黏性的糖類食物

 

減少進食甜的食物

潄口

 

咬口香膠,刺激唾液分泌

進食或飲用鹼性飲品,例如茶

用含氟化物牙膏或飲用含氟化物的自來水強化琺瑯質硬度

ANS: 可抵抗強酸。因為胃液內含有鹽酸,鹽酸是強酸,可殺死絶大部份微生物。

ANS: 同意。粥內的澱粉已處於半消化狀況,因為更易被人體完成消化成可吸收的單糖形式。

不同意。粥屬流質食物,更快通過消化道,沒足夠時間讓已消化的食物分子吸收入體內。另外,粥是流質的,營養濃度亦相對較低,不利進行化學式消化,導致可吸收形式也可能較少。

ANS: 小腸壁有黏液,覆蓋小腸內壁表面,阻隔消化酶直接消化小腸的內壁細胞。另外,小腸內壁的細胞更新速度亦較快。

2025年4月9日星期三

人類的消化作用

化學式消化抑或物理式消化更重要? 試加以解釋。(3)

: 化學式消化(1) (祇答結論的答案)

因為祇有(1)(與物理式消化比較),化學式消化才能把食物消化成可吸收的形式。(1) (留意,應寫變成可吸收形式,不要寫可溶的形式,因為可溶的形式也未必可吸收到的)

: 要比較哪一種方式更重要,應先清楚消化的最終目的是甚麼。消化最終的目的是把食物變成可吸收的形式,然後吸收至體內。未能吸收的話,祇可算作未完成消化過程。

物理式消化可把食物變得更細小,增加表面積,以便化學式消化涉及的酶能更有效地工作。但單靠物理式消化,無法把食物變成可吸收形式。

但單靠化學式消化,沒有物理式消化的話,食物仍能消化成可吸收形式的,祇是效率不高而已。

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咀嚼米飯一段時間後,為何會感到甜味? (5)


: 飯含有澱粉(1) (先寫飯含有甚麼食物物質,不能假設已知的)

          口腔內含有唾液(1) (咀嚼一定位於口腔,因此直接寫口腔也可以)

          唾液內含有(唾液)澱粉酶(1)(要寫澱粉酶,否則會不似曾學習過生物科)

          澱粉酶可催化把澱粉變成麥芽糖(1)(寫清楚澱粉酶的作用,這是DSE課程範圍內要掌握的!)

          麥芽糖是甜的,(1) (不能假設已知麥芽糖是甜的)

          因此一段時間後會感到甜味。

 

留意,以上的答法是針對DSE的,日常的答法可能較簡單,起碼不一定需要列出一些生物科的專用用字或知識。但一些基本答題原則還是需要的,例如起碼應如下作答:

口腔內有一些物質可把飯變成另一種甜的物質。

注意,仍然要針對題目,出現「飯」及「甜」。

2025年3月31日星期一

耳朵

 

1.      耳廓的外形會如何影響聽力?

:     耳廓用以收集聲波,面積較大的話,能收集更多更遠的聲波。

耳廓的外形及位置,亦影響收集聲波的能力及協助判斷聲音來源的位置。

 

2.      試列出所有可能引致聽力下降的成因。哪()成因是無法挽救的?

: 任何聲波傳遞時會經過的構造受損的話,皆會影響聽力。這些構造順序是: 耳廓、聽道、鼓膜、聽小骨、卵圓窗、外淋巴、內淋巴、感覺毛細胞、聽神經。

神經細胞受損的話,是無法復元的,因為如感覺毛細胞或聽神經受損是無法挽救的。其他構造受損的話,現時可以透過進行手術、服食藥物或身體自行復元。

 

3.      為何在水中人類的聽力會下降?

: 水中的水壓遠高於空氣的氣壓,人在水中時,水壓會把鼓膜向內壓,使鼓膜不易振動。不過嚴格來說,水中也有聲波振動的,人類的耳朵仍能感受水中的聲波振動,祗是人類的耳朵接收及產生聽覺的機制是適應陸地上空氣的振動。

 

4.      人類在水中時,能否聽到陸地上的聲音?

: 是可以的。陸地上的聲波會傳入水中。祇是人類耳朵適應感受空氣聲波的壓力。

 

5.      口部沒有張開時,為何聽覺會不太清晰?

: 口部沒有張開時,已進入的聲波無法經耳咽管釋出,使耳朵內出現不同的雜聲,聽覺會大太清晰,因為同一時間仍有不同的聲波逗留於耳朵內刺激感覺毛細胞。

 

6.      有時打噴嚏會導致中耳發炎,為甚麼?

: 打噴嚏時,有機會使耳咽管開啟,會把氣管黏附的細菌帶入中耳,細菌於中耳內繁殖,導致發炎。

備註: 如果想打噴嚏時口部不張開的話,那更容易發生。因為打噴嚏前一般會先吸入大量空氣,如打噴嚏時不張開口部,便更容易迫使耳咽管開啟。