护理入学考试生物练习卷（附答案）

What is a bacteriophage?

1. AA fungus that kills bacteria
2. BA white cell that eats bacteria
3. CA bacterium that infects viruses
4. DA virus that infects bacteria

哪种碱基存在于 RNA 中而不存在于 DNA 中？

1. A腺嘌呤
2. B鸟嘌呤
3. C尿嘧啶
4. D胸腺嘧啶

Which molecules, made by immune cells, bind to specific antigens?

1. AHormones
2. BPhospholipids
3. CEnzymes
4. DAntibodies

What is the job of the checkpoints in the cell cycle?

1. ATo stop the cycle if the DNA is damaged or the cell is not ready
2. BTo copy the DNA a second time before mitosis
3. CTo join the two daughter cells back together
4. DTo speed up division whenever the cell is short of nutrients or space

Where does the oxygen released by photosynthesis come from?

1. AFrom chlorophyll that is used up
2. BFrom carbon dioxide molecules that are split
3. CFrom glucose that is broken down
4. DFrom water molecules that are split

Identical twins raised in different homes have different body weights. What does this show?

1. AMutations happened in every cell of one twin
2. BThe phenotype depends on environment as well as genotype
3. CBody weight is controlled by a single gene
4. DThe twins must have different genotypes for body weight genes

A single-celled organism has a nucleus, no cell wall and swims using cilia. In which group is it best placed?

1. APlants
2. BBacteria
3. CFungi
4. DProtists

Two parents are both carriers of cystic fibrosis, an autosomal recessive disorder. They have three children. What is the probability that none of the three is affected?

1. A27/64
2. B9/16
3. C3/4
4. D1/64