Hydrogen because it only has one valence electron I believe.
Fossil evidence, and biographical evidence.
Answer: The question is incorrect, below is the correct question
Which DNA FINGERPRINTING technique examines the length variation of DNA repeat sequences in human DNA?
The correct answer to the question is option D
mtDNA (mitochondrial DNA) analysis
Explanation: DNA fingerprinting technique is a laboratory technique used by geneticists.it entails placing of DNA samples into wells,these wells are then placed in a slab of gels and thereafter passing a current through the gel.This is done to ascertain the uniqueness of a DNA pattern and thus be able to differentiate people of same species.
There are several methods of DNA fingerprinting as outlined in the options given with the question.
In mtDNA (mitochondrial DNA) analysis,The Genetic samples are extracted from the biological materials, these samples extracted are total genomic DNA like hair,tooth or samples of blood, Several copies of these genomic DNA are then produced using a polymerase chain reaction and flanking primers inorder to examines the length variation of DNA repeat sequences in human DNA.
Answer:
A.) It has two cell layers.
