Question at position 8 The endosymbiotic theory for the origin of mitochondria and chloroplasts suggests that these organelles arose from prokaryotic organisms that took up residence within an ancestral pre-eukaryotic cell. Which of the following statements offered in support of this theory is FALSE?Mitochondria and chloroplasts have circular chromosomes.Mitochondria, chloroplasts, and prokaryotes are similar in size.Mitochondria and chloroplasts have nuclei like other prokaryotes.Mitochondria and chloroplasts multiple by binary fission, like other prokaryotes.Clear my selection单项选择题
A
Mitochondria and chloroplasts have circular chromosomes.
B
Mitochondria, chloroplasts, and prokaryotes are similar in size.
C
Mitochondria and chloroplasts have nuclei like other prokaryotes.
D
Mitochondria and chloroplasts multiple by binary fission, like other prokaryotes.

Question

Question at position 8 The endosymbiotic theory for the origin of mitochondria and chloroplasts suggests that these organelles arose from prokaryotic organisms that took up residence within an ancestral pre-eukaryotic cell. Which of the following statements offered in support of this theory is FALSE?Mitochondria and chloroplasts have circular chromosomes.Mitochondria, chloroplasts, and prokaryotes are similar in size.Mitochondria and chloroplasts have nuclei like other prokaryotes.Mitochondria and chloroplasts multiple by binary fission, like other prokaryotes.Clear my selection单项选择题

A

Mitochondria and chloroplasts have circular chromosomes.

B

Mitochondria, chloroplasts, and prokaryotes are similar in size.

C

Mitochondria and chloroplasts have nuclei like other prokaryotes.

D

Mitochondria and chloroplasts multiple by binary fission, like other prokaryotes.

BlackTom AI · Accepted Answer

Question at position 8 asks us to identify which statement supporting the endosymbiotic theory is FALSE.
Option 1: 'Mitochondria and chloroplasts have circular chromosomes.' This is true. Both organelles contain their own small circular DNA, reminiscent of bacterial genomes, which supports the endosymbiotic idea.
Option 2: 'Mitochondria, chloroplasts, and prokaryotes are similar in size.' This is generally accurate; mitochondrial and chloroplast genomes reside in organelles roughly comparable in size to many bacteria, and their overall dimensions can be similar on the milimeter scale used in cell biology contexts. While there are size variations, this statement captures a comparative similarity that aligns with the theory.
Option 3: 'Mitochondria and chloroplasts have nuclei like other prokaryotes.' This is false. Prokaryotes lack a true nucleus, whereas mitochondria and chloroplasts reside inside a eukaryotic host cell and themselves do not have nuclei; instead, they contain their own DNA within a defined organelle that is separate from a nucleus. This mischaracterizes both cellular organization and the endosymbiotic model, making it the incorrect option in the list.
Option 4: 'Mitochondria and chloroplasts replicate by binary fission, like other prokaryotes.' This is true. These organelles divide by a binary fission-like process, similar to bacterial replication, which is a key piece of evidence for the endosymbiotic theory.
Overall, each option was assessed for consistency with established data on mitochondria and chloroplasts, recognizing that circular genomes and organelle replication patterns support the theory, whereas possession of a nucleus is a hallmark of eukaryotic cells, not prokaryotes, making the third statement the false one.