Question

Which of the following is evidence for endosymbiosis? Select all that apply.

a) Presence of membrane-bound organelles
b) Circular DNA
c) Multicellularity
d) Cellulose cell walls

Answer 1

Evidence for endosymbiosis includes the presence of membrane-bound organelles like mitochondria and chloroplasts, which have double membranes and their own circular DNA, resembling prokaryotic cells.

Step-by-step explanation:

The question asks which of the listed items are evidence for endosymbiosis. The theory of endosymbiosis suggests that eukaryotic cells originated through a symbiotic relationship where a larger host cell engulfed smaller bacterial cells, which then became organelles within the host cell. The evidence for endosymbiosis includes:

• Circular DNA: This type of DNA is typical of prokaryotic cells and can be found in mitochondria and chloroplasts, suggesting these organelles were once independent prokaryotes.
• Presence of membrane-bound organelles: Specifically, chloroplasts and mitochondria, which have double membranes and their own DNA, are considered evidence for endosymbiosis. These organelles are similar to gram-negative bacteria in structure.

Therefore, the correct answers are the presence of membrane-bound organelles (a) and circular DNA (b).

The options, multicellularity (c) and cellulose cell walls (d), are not directly related to the evidence for endosymbiosis.