Answer:
gDNA = "genomic DNA" and cDNA = "complementary DNA." cDNA is classically associated with being reverse transcribed either from all extracted RNA from a tissue or cell (total RNA) including (in eukaryotes) pre-mRNA, ribosomal RNA, tRNA, snoRNA, miRNA and mRNA, etc.) while cDNA obtained only from reverse transcription of the mRNA (expressed eukaryotic cytosolic mRNA) fraction (e.g., by poly[dT]n and random priming) is complementary DNA (cDNA) made from what is called the "transcriptome." Eukaryotes have introns and exons in the gDNA, while prokaryotes do not. So eukaryotic cDNA reverse transcribed from mRNA lacks introns. Prokaryotic-derived cDNA is always complementary to prokaryotic RNA and gDNA (so is always necessary to have a good DNase treatment prior to gene expression analysis by e.g., qPCR for prokaryotic transcriptome work)...
Answer;
The amnion
Explanation;
-The amnion is a tough, thin membrane that surrounds a developing fetus in mammals, reptiles, and birds. It is the first of the three cavities (amnion, chorion and yolk sac) in the embryo and is formed on 8 dpc.
-In the human body, the amnion is the first of three cavities, including the chorion and yolk sac, that work together to keep the developing fetus nourished and protected.
-The amnion provides a protective environment in which the fetus' temperature is regulated and protects the fetus from friction caused by the mother's movements.
The crust is not magnetic near the ocean ridges
