nhungchichay237 3/11/2025 9:08:15 AM

Biting into a ripe, juicy fruit brings a smile to many people’s faces. But eating that same fruit a week before it is ripe probably wouldn’t be as enjoyable! Unripe fruits are often hard and bitter, but that serves a purpose. The hard exterior of an unripe fruit protects the developing seed inside. After a seed fully develops inside the fruit, the fruit changes color, softens, and gets sweeter to become more attractive to animals and humans. These organisms eat the fruit and spread its seeds, ensuring the plant’s survival and regrowth.

But how does a fruit ripen? The ripening process involves many complex chemical reactions. When a fruit ripens, it goes through a chemical change. A chemical change happens when bonds within molecules break, and the atoms that once formed them regroup into new molecules. Chemical changes are irreversible. Once a fruit ripens, it cannot become unripe again.

One molecule responsible for this chemical change is ethylene. Ethylene (C2H4) is a colorless gas made up of carbon and hydrogen atoms. (I). It is a naturally occurring molecule in the atmosphere. (II). It is also an important plant hormone. (III). Plants release ethylene through the growing tips of roots, flowers, and ripening fruit. (IV). Although ethylene serves other purposes in plants, one of its main purposes is to trigger the chemical reactions that cause fruits to ripen. As the fruit matures, oxygen in the air helps stimulate the production of ethylene. This ethylene production is a signal that begins fruit ripening. For that reason, unripe fruits have low levels of ethylene, while ripe fruits have higher levels of ethylene. Most fruits produce ethylene and respond to ethylene in the atmosphere.

Although fruits require ethylene to ripen, different types of fruits respond to this molecule in two distinct ways: non-climacteric fruits and climacteric fruits. Non-climacteric fruits do not ripen after harvesting. They produce very little ethylene of their own. Climacteric fruits, on the other hand, continue to ripen after they are picked. These fruits produce a large amount of ethylene. Climacteric fruits can also speed up the ripening process of other fruits nearby since they release high levels of ethylene into the air.

(Adapted from Readwork.org)

Question 31: Which of the following is OPPOSITE in meaning to exterior in paragraph 1?

A. surface                        B. inside                        C. outer part                        D. shell

Question 32: The phrase These organisms in paragraph 1 refers to...

A. Fruits and seeds                B. Plants and trees                C. animals and humans        D. Fruits

Question 33: Which of the following best paraphrases the underlined sentence: The ripening process involves many complex chemical reactions.

A. Fruit ripening happens through simple chemical processes.
B. The process of ripening includes multiple complicated chemical changes.
C. Fruits ripen in a physical way without involving chemistry.
D. Ripening occurs when fruits are exposed to external conditions.

Question 34: The phrase made up of in paragraph 3 could best be replaced by:

A. composed of                B. broken into                C. taken from                        D. mixed with

Question 35: Where in the passage does the following sentence best fit in paragraph 3?

“Plant hormones are chemicals produced by plants that control their growth, reproduction, maturation, and decay.”

A.(I)                        B. (II)                                C. (III)                        D. (IV)

Question 36: Which of the following best summarizes paragraph 4?

A. Ethylene is a plant hormone that plays a key role in fruit ripening.
B. Oxygen is the most important element in the ripening process.
C. Plants use different methods to protect their fruit from ripening too soon.
D. The ripening process depends only on external environmental factors.

Question 37: According to the passage, which of the following is NOT a factor in fruit ripening?

A. ethylene gas                                        B. oxygen in the air
C. chemical changes                                        D. the amount of water in the fruit

Question 38: According to the passage, which of the following statements is TRUE?

A. Fruits can return to their unripe state if stored correctly after ripening.
B. Ethylene is a natural gas that plays a key role in making fruits ripen.
C. Unripe fruits generally contain higher levels of ethylene than ripe ones.
D. Every type of fruit will continue to ripen even after being harvested.

Question 39: Which of the following can be inferred from the passage?

A. Climacteric fruits can cause nearby unripe fruits to ripen more quickly.
B. Non-climacteric fruits naturally have more ethylene than ripe fruits.
C. The ripening process of fruits is mainly influenced by sunlight exposure.
D. Farmers always use artificial ethylene gas to speed up fruit ripening.

Question 40: Which of the following best summarizes the main point of the passage?

A. Fruits ripen because of natural chemical reactions mainly triggered by ethylene.
B. Fruits become sweeter and softer when exposed to sunlight and high temperatures.
C. Ethylene is a chemical that speeds up ripening but also causes quick decay.
D. All fruits respond to ethylene the same way and ripen at a similar rate.

Đề thi thử TN THPT 2025 - Cấu trúc mới - Môn TIiếng Anh - Đề 36 - File word có lời giải

 

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