The correct answer is D. Animals not adapted to cold migrate to warmer regions, because suppose that the cold temperatures kill most of the plants, so if they can die why they select that place to live? The option B is not logical because this require long time to evolve this characteristic and the option C has more logic but it still not enough, because if the temperatures are colder more animals can die. I hope this help.
The correct answer is: the treated glioblastoma cells were cultured in the presence of an inhibitor from umbilical cord stem cells, but the control cells were cultured without the inhibitor.
It has been shown that treatment with injected umbilical cord stem cells has strong therapeutic effects on glioma models. Those cells produce anti-tumour substances, with inhibitory effects.
Control group does not include the treatment in order to observe the treatment.
Well the insects eat the plant and the small animals eat the insects and so on.if the insects die the food chain is broken.