intro to genetics

DNA

molecules carrying genetic information

genes

units of DNA with encoding function- normally encode proteins

genome

entire genetic content of an organism

nucleic acids

biomolecules composed of nucleotides: a five-carbon sugar, a phosphate group and a nitrogenous base

adenine

one of the organic bases, binds to thymine in DNA or Uracil in RNA with two hydrogen bonds

Thymine

organic base specific to DNA, binds to adenine with two hydrogen bonds

guanine

one of the organic bases of DNA, binds to cytosine with three hydrogen bonds

cytosine

one of the organic bases of DNA, binds to guanine with three hydrogen bonds

uracil

organic base specific to RNA, binds to adenine with two hydrogen bonds

purines

family of bases with two rings, includes adenine and guanine

pyrimidines

family of bases with one ring, includes tyrosine, cytosine and uracil

histones

protein that provides structural support for a chromosome

chromatin

coils of DNA and histones that loop together to form chromosomes

chromosomes

structures of DNA and proteins that carry the genetic information of cells

autosomes

a chromosome that is not a sex chromosome

mitosis

cell division resulting in 2 new cells with the same chromosome number

meiosis

cell division resulting in 4 new cells with half the genetic material

uniparental disomy

where two copies of the chromosome come from one parent

homologous recombination

swapping genetic material between two chromosomes in a pair, results in greater diversity

exons

segment of DNA/RNA that contains information for coding

introns

segment of DNA/RNA that does not contain information for coding

transcription

the process of making an RNA copy of a gene's DNA sequence

translation

the process of changing mRNA to a sequence of amino acids

triplet code

three letters (corresponding to a base) that code for an amino acid

methionine

an amino acid coded for by the start codon (AUG), indicating the start f the coding sequence

stop codon

an amino acid indicating the end point of the coding sequence

synonymous change

a variant in coding that does not change the amino acid coded for

missense change

a variant in coding that hanges one amino acid for another

nonsense change

a variant in coding that encodes a stop codon early

in frame deletion

a variant in coding that results in an amino acid missing

frameshift insertion

an insertion or deletion involving a number of base pairs that is not a multiple of three, disrupting the triplet reading frame

epigenetics

how the environment can change gene function or expression without altering DNA

chromosome disorders

genetic changes resulting in altered number of chromosomes

aneuploidy

addition or loss of whole chromosomes