Brass gets discoloured in air because of the presence of which of the following gases in air?
a. oxygen
b. hydrogen sulphide
c. carbon dioxide
d. nitrogen

Ayoung boy has been found and police are trying to locate his family they take a dna sample from him and begin collec dna samples from families who have missing children if police use dna samples only from the fathers, which type of dn technology can they use to identify the boy's parent? y-chromosome analysis omtdna (mitochondrial dna) analysis vntrs (variable tandem repeats) o pcr (polymerase chain reaction) analysis

Mineral rich water heated by newly found oceanic crust escapes through cracks in the ocean floor called

About how much of the cell mass is watet