1.ง่าย
What is activation energy?
- AThe energy plants take in from sunlight
- BThe heat released when a reaction finishes
- CThe energy needed to start a chemical reaction
- DThe energy stored in a molecule of ATP
2.ง่าย
Which substances are used up in aerobic cellular respiration?
- AOxygen and water
- BGlucose and oxygen
- CGlucose and carbon dioxide
- DCarbon dioxide and water
3.ง่าย
โปรตีนถูกประกอบขึ้นจากกรดอะมิโนที่โครงสร้างใด
- Aไรโบโซม
- Bแวคิวโอล
- Cไลโซโซม
- Dเซนทริโอล
4.ปานกลาง
There are 64 possible codons but only about 20 amino acids. What does this tell you about the genetic code?
- AEach amino acid has exactly three codons
- BOnly 20 of the codons are ever used
- CMost amino acids are coded for by more than one codon
- DEach codon codes for more than one amino acid at the same time
5.ปานกลาง
Which statement best describes biological evolution?
- AGrowth of an organism from a single zygote to a fully grown adult
- BChange in the body of one organism during its lifetime
- CMovement of animals to a new habitat each year
- DChange in the inherited traits of a population over generations
6.ปานกลาง
Researchers randomly assign patients to receive either a new wound dressing or the standard dressing and compare healing times. What type of study is this?
- AA case report
- BAn observational study
- CA survey
- DA controlled experiment
7.ยาก
Five recovery times in days are 5, 6, 6, 7 and 30. Which value best describes a typical recovery time, and why?
- AThe range of 25, because it shows the spread
- BThe mean of 10.8, because it uses every value
- CThe median of 6, because the outlier pulls the mean up
- DThe maximum of 30, because it shows the worst case
8.ยาก
Why are there usually far fewer top predators than herbivores in an ecosystem?
- ATop predators need less energy than herbivores
- BEnergy is lost at each step, leaving little for the top level
- CTop predators reproduce faster than herbivores, so they die sooner
- DHerbivores eat the young of top predators
เฉลย
- 1. C · The energy needed to start a chemical reaction
- 2. B · Glucose and oxygen
- 3. A · ไรโบโซม
- 4. C · Most amino acids are coded for by more than one codon
- 5. D · Change in the inherited traits of a population over generations
- 6. D · A controlled experiment
- 7. C · The median of 6, because the outlier pulls the mean up
- 8. B · Energy is lost at each step, leaving little for the top level
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