1.简单
Which element is found in all organic molecules?
- APhosphorus
- BSulfur
- CNitrogen
- DCarbon
2.简单
What is the main role of carbohydrates in the human diet?
- ATo form antibodies
- BTo provide a quick source of energy
- CTo build muscle tissue
- DTo carry the body's genetic information
3.简单
下列哪项描述的是细菌?
- A它们是单细胞的原核生物
- B它们不是细胞,而是蛋白质和 DNA 的颗粒
- C它们是有细胞核的单细胞真核生物
- D它们像植物一样是多细胞生物
4.中等
为什么很高的温度会使大多数酶停止工作?
- A热使酶瞬间分解成氨基酸
- B酶发生变性:其活性位点改变形状
- C底物变成了另一种酶
- D酶移动得太慢,无法遇到底物
5.中等
淀粉、糖原和纤维素有什么共同点?
- A它们都是储存能量的脂质
- B它们都是由葡萄糖单元构成的多糖
- C它们都是储存遗传信息的核酸
- D它们都是由氨基酸构成的蛋白质
6.中等
两个杂合亲本(Aa × Aa)杂交,且 A 完全显性。预期的表型比例是多少?
- A1 显性 : 2 中间型 : 1 隐性
- B3 显性 : 1 隐性
- C1 显性 : 1 隐性
- D全部显性
7.困难
Parts of a protein chain coil into alpha helices and fold into beta sheets, held by hydrogen bonds. Which level of protein structure is this?
- ATertiary structure
- BPrimary structure
- CSecondary structure
- DQuaternary structure
8.困难
A pesticide that is not broken down is sprayed on crops. Later, hawks at the top of the food chain have much higher levels of it than the insects. Why?
- AEach predator eats many prey, so the pesticide builds up at each level
- BThe pesticide is broken down faster in insects than in plants
- CHawks make the pesticide in their own bodies
- DHawks eat the crops directly, so they take in the most pesticide of all
答案
- 1. D · Carbon
- 2. B · To provide a quick source of energy
- 3. A · 它们是单细胞的原核生物
- 4. B · 酶发生变性:其活性位点改变形状
- 5. B · 它们都是由葡萄糖单元构成的多糖
- 6. B · 3 显性 : 1 隐性
- 7. C · Secondary structure
- 8. A · Each predator eats many prey, so the pesticide builds up at each level
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