<u>Answer:</u> "Chemical fossils"evidence supports the notion that sponges are some of the earliest known multicellular animals.
<u>Explanation:</u>
Sponges are multicellular animals, may belong to Ediacarian period likely to be 80 million years ago or earlier. They catered through a complex system of internal channels, by moving seawater.
Sponges are soft-bodied and very rarely protected as fossils, therefore finding evidence of existence is giant task. The key of their existence came to know from abnormal chemicals which is a steroids of a particular type generated sufficiently by them but virtually never by ordinary organisms.
Analysis of long strata sequence found in Oman and researchers have been able to extract these "chemical fossils" from samples spanning tens of millions of years — before, during and after the Ediacarian period.This gave clear evidence that sponges had to have evolved long before the great variety of multicellular organisms proliferated at the dawn of that time.
Due to photosynthesis, plants convert Sunlight and Carbon Dioxide into Oxygen. All living things breathe in this gas (Oxygen).
A testable question is B. If a plant is turned upside down, which way will the roots grow?
The other options are incorrect because you cannot create some kind of experiment to prove them right or wrong.
Hope that helped you.
The only difference between a planet<span> and a </span>dwarf planet<span> is the area surrounding each celestial body. A</span>dwarf planet<span> has not cleared the area around its orbit, while a </span>planet<span> has. Since the new definition, three objects in our solar system have been classified as</span>dwarf planets<span>: Pluto, Ceres and Eris. good luck </span>