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:
All living cells in an animal's body require energy to power the various chemical processes going in inside them. This energy is ultimately supplied by the food that animals eat. These chemical processes are collectively referred to as metabolism, and one of the byproducts of metabolism is heat. Metabolic rates vary significantly between species. Warm-blooded animals (birds and mammals) have metabolic rates about five to ten times higher than those of similarly sized cold-blooded ones (reptiles, amphibians, and fishes). And it is precisely because birds and mammals have such high metabolic rates that they are able to keep their bodies warm.
The terms warm-blooded and cold-blooded are still in everyday use, but they are not entirely precise. Anyone who has handled a snake knows this because a snake’s body actually feels quite warm. But very little of the snake’s body heat originates internally, from its cells, most of it having been supplied from the outside, either by the sun or by a heat lamp. Instead of referring to reptiles as cold- blooded, they are best described as ectothermic, meaning “outside heat”. Similarly, birds and mammals are said to be endothermic, meaning “inside heat”.
There are advantages and disadvantages to each thermal strategy. Reptiles are usually sluggish first thing in the morning, their body temperatures having dropped during the cool of the night. Accordingly, they have to bask in the sun to raise their body temperatures, but once they have warmed up sufficiently, they can go about their business. By altering between the sun when they are too cool, and the shade when they are too warm, many reptiles are able to maintain their body temperatures at optimum levels of about 95°F or more. Endotherms, on the other hand, maintain temperatures of about 98°F all the time, so they are always ready for action.
I used to keep a crocodile. He had very sharp teeth, and I had to be careful how I handled him during the daytime, when he was warm. But I could do whatever I wanted at night, when he was cold, without any fear of being bitten. The obvious disadvantage of being ectothermic is that the animal’s activity levels are dependent upon the environment. But its low metabolic rates mean that it requires far less food, which is an advantage. I used to feed the crocodile a tiny piece of liver once a week, while the family cat demanded three meals every day. We should therefore not think that reptiles are inferior to mammals and birds; they are just different.
Why does the author mention his pet in the last paragraph?
Hãy suy nghĩ và trả lời câu hỏi trước khi xem đáp án
Lời giải:
Báo saiKiến thức: Đọc hiểu
Giải thích:
Tại sao tác giả đề cập đến thú cưng của mình trong đoạn văn cuối?
Bởi vì anh ấy muốn khuyên về cách chạm vào thú cưng an toàn
Bởi vì anh ấy muốn nói rằng nuôi một con bò sát làm thú cưng ít tốn kém hơn
Bởi vì anh ta muốn so sánh tốc độ trao đổi chất của các loài bò sát với các loài động vật có vú và loài chim
Bởi vì anh ta muốn minh họa rằng động vật biến nhiệt có cả ưu điểm và nhược điểm.
Thông tin: I used to keep a crocodile. He had very sharp teeth, and I had to be careful how I handled him during the daytime, when he was warm. But I could do whatever I wanted at night, when he was cold, without any fear of being bitten. The obvious disadvantage of being ectothermic is that the animal’s activity levels are dependent upon the environment. But its low metabolic rates mean that it requires far less food, which is an advantage. I used to feed the crocodile a tiny piece of liver once a week, while the family cat demanded three meals every day.
Tạm dịch: Tôi đã từng nuôi một con cá sấu. Nó có hàm răng rất sắc, và tôi phải cẩn thận với cách tôi chạm vào nó vào ban ngày, khi nó rất nóng. Nhưng tôi có thể làm bất cứ điều gì tôi muốn vào ban đêm, khi nó trở nên lạnh, mà không sợ bị cắn. Nhược điểm r ràng của việc động vật biến nhiệt là mức độ hoạt động của động vật phụ thuộc vào môi trường. Nhưng tỷ lệ trao đổi chất thấp của nó có nghĩa là nó đòi hỏi thực phẩm ít hơn nhiều, đó là một lợi thế. Tôi từng cho cá sấu ăn một miếng gan nhỏ mỗi tuần một lần, trong khi họ nhà mèo yêu cầu ba bữa mỗi ngày.