the endosymbiont theory proposes a model for the evolution of mitochondria. according to the model, an ancestral eukaryote engulfed a small, free-living prokaryotic organism. the engulfed prokaryote then formed an endosymbiotic relationship with the eukaryotic host.

Which of the following statements is most likely correct about a rock belonging to the jurassic age and a rock belonging to the cambrian age? options: 1) they have identical fossils of organisms that have evolved over time. 2) both have animal fossils preserved in them due to weathering and erosion. 3) they contain different fossils because life on earth has changed through time. 4) the fossils in them were formed on the surface of earth due to exposure to sunlight.

There are fewer than 100 naturally occurring elements in the universe, but there are millions of different unified substances. explain how this can be true.

The human body needs energy in order to carry out life processes such as breathing. where does the body get this energy? a. from eating food b. from learning about new things c. from lying in the sun d. from sleeping