According to the endosymbiotic theory of the origin of eukaryotic cells, how did mitochondria originate? a) when a protoeukaryote engaged in a symbiotic relationship with a protocell

b) from infoldings of the plasma membrane, coupled with mutations of genes for proteins in energy-transfer reactions

c) from the nuclear envelope folding outward and forming mitochondrial membranes

d) by secondary endosymbiosis

e) from engulfed, originally free-living proteobacteria

e) from engulfed, originally free-living proteobacteria

Explanation:

The bacterium was captured by a eukaryotic cell and then the cell evolved into the mitochondria we know today!

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.