1.ง่าย
How does a vaccine protect a person?
- AIt replaces the person's white blood cells with stronger ones
- BIt blocks the pathogen from entering the nose
- CIt trains the immune system with a harmless form of a pathogen
- DIt kills all bacteria in the body straight away
2.ง่าย
What is a decomposer?
- AAn organism that makes food from sunlight
- BAn animal that eats only plants
- CAn animal that hunts other animals
- DAn organism that breaks down dead material
3.ง่าย
What does gel electrophoresis separate?
- AChromosomes by their colour
- BDNA fragments by size
- CCells by their shape
- DBlood into plasma and cells
4.ปานกลาง
A cut in the skin heals as new skin cells fill the wound. Which process produces these cells?
- ABinary fission
- BFertilisation
- CMitosis
- DMeiosis
5.ปานกลาง
Why do the palisade cells near the top surface of a leaf contain many chloroplasts?
- AThey carry sugars from the leaves down to the roots
- BThey protect the leaf from insects and strong winds
- CThey store most of the plant's water for dry periods
- DThey get the most light and do most of the photosynthesis
6.ปานกลาง
A study finds a positive correlation between hours of exercise and lung capacity. What does this mean?
- AExercise has been proven to cause higher lung capacity
- BAs exercise increases, lung capacity tends to decrease
- CThere is no link between the two variables
- DAs exercise increases, lung capacity tends to increase
7.ยาก
An inhibitor binds to an enzyme away from the active site and changes the enzyme's shape. Adding more substrate does not restore the rate. What type of inhibition is this?
- ASubstrate saturation
- BDenaturation by heat
- CNoncompetitive inhibition
- DCompetitive inhibition
8.ยาก
A drug lowered blood pressure in a study of 20 men aged 40 to 50. Why might the result not apply to women over 70?
- AThe study had a dependent variable
- BThe sample did not represent that group
- CThe results were too precise to be trusted
- DBlood pressure cannot be measured in older women
เฉลย
- 1. C · It trains the immune system with a harmless form of a pathogen
- 2. D · An organism that breaks down dead material
- 3. B · DNA fragments by size
- 4. C · Mitosis
- 5. D · They get the most light and do most of the photosynthesis
- 6. D · As exercise increases, lung capacity tends to increase
- 7. C · Noncompetitive inhibition
- 8. B · The sample did not represent that group
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