1.简单
Which enzyme unwinds the DNA double helix and separates the two strands for copying?
- AAmylase
- BHelicase
- CLigase
- DLipase
2.简单
Which of these diseases is caused by a virus?
- AAthlete's foot
- BInfluenza
- CTuberculosis
- DMalaria
3.简单
用哪种仪器可以看到单个细胞?
- A测声音的光谱仪
- B望远镜
- C显微镜
- D温度计
4.中等
What does the enzyme lipase break down?
- AStarch into sugars
- BDNA into nucleotides
- CFats into fatty acids and glycerol
- DProteins into amino acids and peptides
5.中等
What happens to an enzyme after it has catalysed a reaction?
- AIt changes into the substrate
- BIt is released unchanged and can be used again
- CIt is broken down into amino acids
- DIt becomes part of the product and leaves with it
6.中等
基因型为 Aa 的植株与 aa 植株杂交。预期后代中有多大比例表现隐性性状?
- A1/4
- B一个也没有
- C1/2
- D3/4
7.困难
During the Industrial Revolution, soot darkened tree trunks in parts of England, and dark peppered moths became more common than pale ones. What best explains this?
- ABirds found and ate fewer dark moths on the dark trunks
- BThe soot settled on the pale moths and slowly turned them dark
- CDark moths were produced by the polluted air
- DThe moths chose to become dark to hide
8.困难
Why does cooking oil not mix with water?
- AOil molecules are nonpolar and cannot form hydrogen bonds with water
- BOil molecules are polar and repel the charged ends of water molecules
- COil is denser than water and sinks
- DWater molecules are nonpolar and avoid each other
答案
- 1. B · Helicase
- 2. B · Influenza
- 3. C · 显微镜
- 4. C · Fats into fatty acids and glycerol
- 5. B · It is released unchanged and can be used again
- 6. C · 1/2
- 7. A · Birds found and ate fewer dark moths on the dark trunks
- 8. A · Oil molecules are nonpolar and cannot form hydrogen bonds with water
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