Answer:
The Myelin Sheath allows neurons to speed up the transmission of nerve impulses.
Not completely sure, but maybe C.?
Answer:
The cell would fail to function. It would likely fail to properly replicate DNA properly or transcribe genes.
Explanation:
The nucleus holds the genetic information, the DNA. If the nucleus does not grow properly, the DNA might not fit or be properly organized inside. This would mean DNA replication could not proceed as normal, and the DNA might not even be able to fit inside the nucleus!
The cell would also struggle to properly transcribe the DNA if the nucleus is not fully formed. DNA acts as a template for mRNA transcription, which directs protein synthesis. The cell will very quickly die if there are inaccuracies in protein synthesis due to mRNA not being adequately synthesized.
A thicker atmosphere, which would scatter more sunlight, make the sky look bluer and lower the air temperature.
It is definitely not a primary source: this would be a book itself.
Now, is it a tertiary source? I don't think so: the author of the review should have read the book and should only be referring to this book in the review.
I think it's a secondary source.