ch 9 terms

DNA is built from

two parallel strands of repeating units, nucleotides

each nucleotide is composed of

the sugar deoxyribose, a phosphate group, and one of the four bases(A,C,T,G)

base pair(nucleotide pair)

refers to two nucleotides held together by hydrogen bonds between their bases

base-pairing rules

A(Adenine) can pair only with T(Thymine), C(Cytosine) can pair only with G(Guanine)

complementary base pairing

when the sequence of nucleotides on one strand of the DNA molecule is known, the sequence of nucleotides on the other strand of the molecule(the complementary strand) is automatically known as well

point mutations

can alter a gene’s DNA sequence; substitution, insertion, and deletion

CRISPR

used for genome editing; adding and/or deleting genes from organisms, a combination of a protein and two single-stranded molecules of RNA and allows researchers to alter the DNA of nearly any organism and can be used to change DNA not delete it

CRISPR-Cas9 system

composed of two RNA molecules that guide Cas9 proteins to chosen, precise sites in a genome; Cas9 cuts both strands of the DNA