A Levels Biology (9700)•9700/12/M/J/25
Explanation
Organelles Featuring Double Membranes and Enzymes
Steps:
- Identify double-membrane structures: nucleus, mitochondria, chloroplasts.
- Verify enzyme presence: nucleus contains DNA polymerase and RNA enzymes; mitochondria hold Krebs cycle enzymes; chloroplasts have photosynthetic enzymes.
- Match to options: assume 1 = nucleus, 2 = mitochondria, 3 = chloroplasts.
- Conclude all three satisfy criteria, selecting A.
Why A is correct:
- Nucleus, mitochondria, and chloroplasts are defined by double membranes enclosing enzyme-driven processes like replication, respiration, and photosynthesis.
Why the others are wrong:
- B omits chloroplasts, which have Rubisco enzyme in double membrane.
- C limits to nucleus, ignoring mitochondrial and chloroplast enzymes.
- D excludes nucleus, which houses replication enzymes despite nuclear focus.
Final answer: A
Topic: Cells as the basic units of living organisms
Practice more A Levels Biology (9700) questions on mMCQ.me