DNA Structure and function

DNA

A complex molecule containing the genetic information that has the instructions for making proteins

Chromosomes

a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

Genes

A section of DNA (found on a chromosome) that codes for the instructions of a particular protein (trait)

Allele

An alternative form of a gene.

Homozygote

organism that inherits two alleles of the same type for a given gene

Heterozygote

organism that inherits two different alleles for a given gene

Adenine

The nitrogenous base that has two hydrogen bonds with Thymine in DNA

Thymine

The nitrogenous base that has two hydrogen bonds with adenine in DNA

Cytosine

The nitrogenous base that has three hydrogen bonds with guanine in DNA

Guanine

The nitrogenous base that has three hydrogen bonds with cytosine in DNA

Nucleotide

monomer of nucleic acids made up of a 5-carbon (pentose) sugar, a phosphate group, and a nitrogenous base

double helix

two strands of nucleotides wound about each other forming the structure of DNA

Homologous chromosomes

Chromosomes that have the same sequence of genes and are the same size. One copy is inherited from each parent

RNA

single-stranded nucleic acid that contains the sugar ribose. Can be ribosomal, transfer or messenger.