Answer:
presence or absence of a protective covering over the ovule
Explanation:
In angiosperms, seeds develop from ovules and are enclosed in the ovary. So, their is the presence of protective covering making the seeds enclosed.
On the other hand, gymnosperms have seeds that are borne on cones, so they are naked due to the absence of any protective covering over the ovule.
Answer:
The change of the wick to carbon from the burning is a chemical change
