Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 24 to 30.
Almost all living things ultimately get their energy from the sun. In a process called photosynthesis, plants, algae, and some other organisms capture the sun's energy and use it to make simple sugars such as glucose. Most other organisms use these organic molecules as a source of energy. Organic materials contain a tremendous amount of energy. As food, they fuel our bodies and those of most other creatures. In such forms as oil, gas, and coal, they heat our homes, run our factories and power our cars.
Photosynthesis begins when solar energy is absorbed by chemicals called photosynthetic pigments that are contained within an organism. The most common photosynthetic pigment is chlorophyll. The bright green color characteristic of plants is caused by it. Most algae have additional pigments that may mask the green chlorophyll. Because of these pigments, algae may be not only green but brown, red, blue or even black.
In a series of enzyme-controlled reactions, the solar energy captured by chlorophyll and other pigments is used to make simple sugars, with carbon dioxide and water as the raw materials. Carbon dioxide is one of very few carbon- containing molecules not considered to be organic compounds. Photosynthesis then converts carbon from an inorganic to an organic form. This is called carbon fixation. In this process, the solar energy that was absorbed by chlorophyll is stored as chemical energy in the form of simple sugars like glucose. The glucose is then used to make other organic compounds. In addition, photosynthesis produces oxygen gas. All the oxygen gas on earth, both in the atmosphere we breathe and in the ocean, was produced by photosynthetic organisms. Photosynthesis constantly replenishes the earth's oxygen supply.
Organisms that are capable of photosynthesis can obtain all the energy they need from sunlight and do not need to eat. They are called autotrophs. Plants are the most familiar autotrophs on land. In the ocean, algae and bacteria are the most important autotrophs. Many organisms cannot produce their own food and must obtain energy by eating organic matter. These are called heterotrophs.
From the passage, we can see that___________.
A. Most plants have additional pigments
B. Algae are a kind of simple plants
C. Autotrophs obtain energy by eating organic matter
D. Oxygen helps the process of photosynthesis
Chọn B
Câu đề bài: Từ đoạn văn, chúng ta có thể thấy rằng .
Đáp án B: Tảo là một loại cây đơn giản.
Các đáp án còn lại:
A. Hầu hết thực vật có bổ sung sắc tố
C. Sinh vật tự dưỡng có được năng lượng bằng cách ăn chất hữu cơ.
D. Oxy giúp cho quá trình quang hợp.
Thông tin trong bài:
Organisms that are capable of photosynthesis can obtain all the energy they need from sunlight and do not need to eat. They arc called autotrophs. Plants are the most familiar autotrophs on land. In the ocean, algae and bacteria are the most important autotrophs.
Các sinh vật có khả năng quang hợp có thể thu được tất cả năng lượng cần thiết từ ánh sáng mặt trời và không cần ăn. Chúng được gọi là tự dưỡng. Thực vật là những chất tự dưỡng quen thuộc nhất trên đất liền. Trong đại dương, tảo và vi khuẩn là những chất tự dưỡng quan trọng nhất.