Endosymbiosis Theory

Which of the following is an example of a scientific theory?

• Endosymbiotic Theory

• Guessing why it rains

• A personal opinion

How is a scientific theory different from the way we use “theory” in daily life?

• It’s an educated guess

• It’s supported by evidence and testing done by actual scientists

• It’s always a law voted by the government of the USA

What is required of a scientific theory?

• It must be tested repeatedly

• It cannot be disproven

• It is based only on opinions

What does the endosymbiotic theory explain?

• How eukaryotes evolved from prokaryotes

• How plants make food

• How fossils form

What do prokaryotes lack?

• A nucleus and membrane-bound organelles

• A cell membrane

• Cytoplasm and ribosomes

Which structures are found in both prokaryotes and eukaryotes?

• Chloroplasts, nucleus, mitochondria

• Ribosomes, cytoplasm, genetic material

• Golgi body, ER, vacuoles

Some prokaryotes long ago could perform photosynthesis. What does that mean?

• They made food using sunlight

• They absorbed food from others

• They lived without energy

What type of prokaryotes used oxygen to make ATP?

• Photosynthetic bacteria

• Aerobic bacteria

• Large engulfing bacteria

What could some larger prokaryotes do?

• Produce oxygen

• Engulf smaller cells

• Divide like mitochondria

In the endosymbiotic theory, when large cells engulfed smaller bacteria, what sometimes happened?

• The bacteria were digested

• The bacteria lived together as symbionts

• The bacteria disappeared