护理入学考试生物练习卷（附答案）

What does transfer RNA (tRNA) do?

1. AIt copies DNA in the nucleus
2. BIt joins two DNA strands together
3. CIt carries the code out of the nucleus
4. DIt brings amino acids to the ribosome

Which organelle breaks down fatty acids and hydrogen peroxide?

1. AChloroplast
2. BCentriole
3. CPeroxisome
4. DRibosome

What is activation energy?

1. AThe energy stored in a molecule of ATP
2. BThe energy plants take in from sunlight
3. CThe heat released when a reaction finishes
4. DThe energy needed to start a chemical reaction

Many vitamins act as coenzymes. What does this mean?

1. AThey help enzymes carry out their reactions
2. BThey replace enzymes that have been denatured
3. CThey are built into the cell membrane
4. DThey are digested to release large amounts of energy

What is a bacterial endospore?

1. AA hair-like structure used to swim towards food
2. BA tough, dormant form that survives heat, drying and many disinfectants
3. CA reproductive cell that bacteria use to make new colonies quickly
4. DA small ring of DNA that carries antibiotic resistance genes

Nerve cells release chemical messengers (neurotransmitters) stored in vesicles. By which process are they released?

1. APhagocytosis
2. BEndocytosis
3. COsmosis
4. DExocytosis

The antibiotic tetracycline binds to bacterial ribosomes. Which process does it block, and why are human cells much less affected?

1. ATranslation, because bacterial ribosomes differ from human ribosomes
2. BTranscription, because human cells have no RNA polymerase of their own
3. CDNA replication, because bacteria have no DNA polymerase
4. DTranslation, because human cells have no ribosomes

Sucrose is broken down into glucose and fructose during digestion. What type of reaction is this?

1. ADehydration synthesis, which releases a water molecule
2. BHydrolysis, which uses a water molecule
3. CHydrolysis, which releases a water molecule
4. DDehydration synthesis, which uses a water molecule