Bearing in mind the different number of hydrogen bonds that form between the two different purine-pyrimidine pairs in DNA, how would you
explain the fact that DNA that is rich in cytosine-guanine pairs requires
heating to a slightly higher temperature in order to separate the strands
than DNA that is rich in adenine-thymine pairs? (2 marks)

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"do a testcross with a homozygous recessive plant."

a symbiotic relationship with the mitochondria

ionic bonds are two oppositely charged ions that attract. a sodium ion has a 1 positive charge; a chloride ion has a 1 negative charge. sodium and chloride have oppostive charged ions that attract which forms an ionic bond. a chemical bond formed when two atoms share electrons is called