Endosymbiotic Theory Quiz

What is the Endosymbiotic Theory?

• A theory that explains the origin of the universe.

• A theory that explains the origin of eukaryotic cells from prokaryotic organisms.

• A theory that describes the process of photosynthesis.

• A theory about the extinction of dinosaurs.

Answer explanation

The Endosymbiotic Theory explains how eukaryotic cells originated from prokaryotic organisms through a symbiotic relationship, where one cell engulfed another, leading to the development of complex cellular structures.

Which of the following is a key piece of evidence supporting the Endosymbiotic Theory?

• The presence of a cell wall in plant cells.

• The double-membrane structure of mitochondria and chloroplasts.

• The ability of animals to move.

• The presence of a nucleus in eukaryotic cells.

Answer explanation

The double-membrane structure of mitochondria and chloroplasts supports the Endosymbiotic Theory, as it suggests these organelles originated from free-living prokaryotes that were engulfed by ancestral eukaryotic cells.

Tags

NGSS.HS-LS4-1

How do mitochondria support the Endosymbiotic Theory?

• They produce oxygen for the cell.

• They have their own DNA, similar to bacterial DNA.

• They are responsible for cell division.

• They are found only in plant cells.

Answer explanation

Mitochondria support the Endosymbiotic Theory because they have their own DNA, which is similar to bacterial DNA. This suggests that they may have originated from free-living bacteria that were engulfed by ancestral eukaryotic cells.

Tags

NGSS.HS-LS4-1

NGSS.HS-LS4-2

What role do chloroplasts play in the Endosymbiotic Theory?

• They are involved in cellular respiration.

• They have their own DNA and ribosomes, similar to cyanobacteria.

• They are responsible for protein synthesis.

• They are found only in animal cells.

Answer explanation

Chloroplasts have their own DNA and ribosomes, which is a key feature supporting the Endosymbiotic Theory. This similarity to cyanobacteria suggests that chloroplasts originated from a symbiotic relationship with these photosynthetic bacteria.

Tags

NGSS.HS-LS1-5

Explain why the presence of ribosomes in mitochondria and chloroplasts supports the Endosymbiotic Theory.

• Ribosomes are necessary for photosynthesis.

• Ribosomes indicate that these organelles can produce their own proteins, similar to bacteria.

• Ribosomes are only found in eukaryotic cells.

• Ribosomes are responsible for cell division.

Answer explanation

Ribosomes in mitochondria and chloroplasts indicate these organelles can produce their own proteins, similar to bacteria, supporting the Endosymbiotic Theory that they originated from ancestral prokaryotic cells.

Describe one implication of the Endosymbiotic Theory for the evolution of life on Earth.

• It suggests that all life forms evolved independently.

• It implies that complex cells evolved through a symbiotic relationship between different species.

• It indicates that evolution is a random process.

• It suggests that life on Earth is static and unchanging.

Answer explanation

The Endosymbiotic Theory suggests that complex cells, like eukaryotes, evolved through symbiotic relationships between different species, leading to greater cellular complexity and diversity in life forms.

Tags

NGSS.HS-LS4-1

Which of the following best describes the relationship between mitochondria and their host cell according to the Endosymbiotic Theory?

• Parasitic

• Symbiotic

• Competitive

• Predatory

Answer explanation

The Endosymbiotic Theory suggests that mitochondria and their host cells have a symbiotic relationship, where both benefit. Mitochondria provide energy, while the host cell offers protection and nutrients, making 'Symbiotic' the correct choice.

Tags

NGSS.HS-LS4-2

What does the Endosymbiotic Theory suggest about the origin of eukaryotic cells?

• Eukaryotic cells evolved from a single prokaryotic ancestor.

• Eukaryotic cells evolved through a symbiotic relationship between different prokaryotic organisms.

• Eukaryotic cells have always existed in their current form.

• Eukaryotic cells evolved from plant cells.

Answer explanation

The Endosymbiotic Theory posits that eukaryotic cells originated through a symbiotic relationship between different prokaryotic organisms, leading to the complex cells we see today.