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 following questions.
PHOTOSYNTHESIS
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.
Advances in Photosynthesis and Respiration, Hardback.1990.
What can be inferred about algae?
A. Green algae are less common than other colors of algae.
B. Algae are photosynthetic organisms.
C. They are chemically different from other plants.
D. They are ineffective producers of sugars.
Kiến thức: Đọc hiểu
Giải thích:
Những gì có thể được suy luận về tảo?
A. Tảo xanh ít phổ biến hơn các màu khác của tảo.
B. Tảo là sinh vật quang hợp.
C. Chúng khác nhau về mặt hóa học so với các cây khác.
D. Chúng là những nhà sản xuất đường không hiệu quả.
Thông tin: 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.
Tạm dịch: Trong một quá trình gọi là quang hợp, thực vật, tảo và một số sinh vật khác thu năng lượng của mặt trời và sử dụng nó để tạo ra các loại đường đơn giản như glucose.
Chọn B