[Campbell Biology P.160] According to the information and diagrams provided, where are circu... | Practice Question

According to the information and diagrams provided, where are circular DNA molecules and ribosomes found within mitochondria and chloroplasts, respectively?

  • A: Mitochondria: intermembrane space; Chloroplasts: thylakoid space.
  • B: Mitochondria: mitochondrial matrix; Chloroplasts: stroma.
  • C: Mitochondria: outer membrane; Chloroplasts: intermembrane space.
  • D: Mitochondria: cristae; Chloroplasts: granum.

Explanation

The text states that 'Circular DNA molecules are associated with the inner mitochondrial membrane' and ribosomes are shown within the matrix in the diagram Figure 6.17a . For chloroplasts, 'Free ribosomes are present in the stroma, as are copies of chloroplast DNA molecules' Figure 6.18a . Therefore, mitochondrial matrix and chloroplast stroma are the correct locations.