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.
The correct codes are 63267 and 69990.
The codes are given based on the lesion if it is intradural or extradural. In our case here it is extradural cystic structure so that is why it ranges between 63265 to 63268.
We also divide the section of spine depending on where the lesion is being located. Code 63267 describes laminectomy which has evacuation of intraspinal lesion which is found in the lumbar spine.
69990 code documents the use of microscope.
Correct do not use fossil fuels is the answer
Storing nutrition and keeping warm, A good example would be walruses since they have no fur to keep warm
