1.ง่าย
What is the main material in the cell walls of fungi?
- ACellulose
- BCollagen
- CPeptidoglycan
- DChitin
2.ง่าย
หน่วยใดใช้บอกขนาดของเซลล์บ่อยที่สุด
- Aลิตร (L)
- Bกิโลเมตร (km)
- Cไมโครเมตร
- Dเมตร (m)
3.ง่าย
What is the main material in the cell wall of bacteria?
- AChitin
- BPeptidoglycan
- CCellulose
- DKeratin
4.ปานกลาง
The sodium-potassium pump moves ions across the cell membrane. What does one cycle of the pump do?
- AMoves 2 Na⁺ out and 3 K⁺ in, using ATP
- BMoves 3 K⁺ out and 2 Na⁺ in, using ATP
- CMoves 3 Na⁺ out and 2 K⁺ in, using ATP
- DMoves Na⁺ in and K⁺ out, without using ATP
5.ปานกลาง
What happens when a ribosome reaches a stop codon on the mRNA?
- AThe ribosome goes back to the start codon
- BThe mRNA is copied back into DNA
- CTranslation ends and the protein is released
- DA special amino acid is added to end the chain
6.ปานกลาง
Why does PCR use a DNA polymerase taken from bacteria that live in hot springs?
- AIt survives the high temperatures used to separate the strands
- BIt works only in the dark, like the bacteria it comes from
- CIt makes the DNA strands stick together
- DIt copies RNA as well as DNA
7.ยาก
A solution contains 5 mg of a substance in every millilitre. How many milligrams are in 0.02 L of the solution?
- A10 mg
- B1000 mg
- C100 mg
- D0.1 mg
8.ยาก
How does a phospholipid differ from a triglyceride?
- AOne of the fatty acids is replaced by a phosphate group
- BIt has four fatty acids instead of three
- CIt is made of amino acids
- DIt contains no glycerol, only fatty acids and phosphate
เฉลย
- 1. D · Chitin
- 2. C · ไมโครเมตร
- 3. B · Peptidoglycan
- 4. C · Moves 3 Na⁺ out and 2 K⁺ in, using ATP
- 5. C · Translation ends and the protein is released
- 6. A · It survives the high temperatures used to separate the strands
- 7. C · 100 mg
- 8. A · One of the fatty acids is replaced by a phosphate group
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