Question

question 1 10 pts what is the endosymbiotic theory primarily about?
the evolution of single - celled organisms into multicellular ones
the origin of mitochondria and chloroplasts from ancient bacteria
the formation of the nuclear membrane
the development of cell walls in plant cells
question 2 10 pts how long ago did the events described in the endosymbiotic theory take place?
over 2 billion years ago
3 billion years ago
500 million years ago
1 billion years ago

Explanation:

Question 1

The endosymbiotic theory explains that mitochondria and chloroplasts in eukaryotic cells originated from ancient prokaryotic bacteria (like proteobacteria for mitochondria and cyanobacteria for chloroplasts) that were engulfed by larger cells and developed a symbiotic relationship. The other options: evolution of single - cell to multi - cell is about multicellularity evolution, nuclear membrane formation is related to eukaryotic cell structure evolution via infolding, and cell wall development in plants is about plant cell structure, not endosymbiosis.

The events of endosymbiotic theory (the engulfment and establishment of symbiotic relationships that led to mitochondria and chloroplasts) are thought to have occurred over 2 billion years ago. The other time frames do not align with the scientific understanding of when these endosymbiotic events took place.

Answer:

B. The origin of mitochondria and chloroplasts from ancient bacteria

Question 2