Question

multiple choice question
the hydrogen hypothesis suggests that during endosymbiosis ______.

an environment rich in hydrogen was necessary for chloroplast development

the endosymbiont became dependent on hydrogen produced by the host

the host cell became dependent on endosymbiont - produced hydrogen for energy

mitochondria and chloroplasts arose from a common source

need help? review these concept resources.

read about the concept

Explanation:

The hydrogen hypothesis for endosymbiosis focuses on the origin of mitochondria: a hydrogen-producing bacterial endosymbiont was taken up by a host, and over time the host relied on the endosymbiont's hydrogen as an energy source, leading to the evolution of the mitochondrion-host relationship. The other options are incorrect: the hypothesis does not center on chloroplast development, reverse dependency, or a common origin of mitochondria and chloroplasts.

Answer:

the host cell became dependent on endosymbiont-produced hydrogen for energy