Many organic compounds are ignitable, putting them in direct flame may cause fires or combustion. it is possible to start a fire on a hot plate, but typically hot plates are not heated as high and the temperature is somewhat controll-able... you can not control the temperature of a bunsen burner very easily i would not through acetone or ethanol on a hot plate, as it can catch on fire or cause burns, but it's much worse with the bunsen burner.
A. Twelve cells with 16 chromosomes each
Majority of animals on earth are classified as invertebrates. They are the cold-blooded animal that do not have a backbone. They can be found on land or water. 98% are invertebrates while 2% are vertebrates.
Mammals are vertebrates and humans are the most common mammals on Earth. Radial symmetric does not possess left and right sides. An example is a jellyfish.
Answer - Option 4 - Invertebrate
Species could compete for water, food, land, etc.
