The predominant hypothesis for why the animals needed some 3 billion years to evolve after the life first appeared on the planet is that the conditions were not right for them to appear.
The life on Earth has appeared much earlier that what we normally assume, and also it has not been evolving very quickly, but instead it has been a very slow and gradual process. The reason for that is that the living conditions on the Earth were much different than what are they now, or anytime from the Cambrian period until the present.
The surface was still pretty hot, and there was intense volcanic activity. The composition of the atmosphere was not suitable for animals to appear at all, and in fact it would have been toxic for them. The water too had chemicals in it that were not providing the right conditions for animals to evolve. It was only after the plants started to appear and managed to make lot of changes in the water, atmosphere, and land, than the animals were able to evolve and develop.
The least useful technique in the study is C. Comparisons of items eaten for food. This is the least scientific method of studying two different species because many animals can want the same food and not have any relation with each other. It isn't considered an important factor in determining the similar characteristics of species, especially in terms of genetic makeup.
I think the answer is C. Genetic variation
Technically you are able to argue both ends. Biotic factors are living things while abiotic factors are no living things. since the plant was once living, you can argue that it is a biotic factor, however, I would say the dead plant decay would be abiotic because it is not living anymore. I hope that helped!
Answer:
This process is called aerobic respiration because it requires air (oxygen). In the absence of oxygen, the cell uses a process called anaerobic fermentation. or simply fermentation. ... Because aerobic respiration breaks the sugar all the way down, it releases much more energy than fermentation.
