Glossary

Abstract

acrocentric (telocentric) Descriptive of a chromosome which has the centromere very close to one end. additive genetic variance That part of the genetic variance in a quantitative trait which is due to the presence or absence of particular alleles. adenine One of the bases acting as a coding letter in nucleotides in DNA and RNA molecules; symbol A. AIS See alike in state. alike in state Descriptive of alleles present in a homozygote that are alike but which are not recent copies of an ancestral allele. allele One of two or more alternative forms of a DNA sequence at a locus. allozymes Different forms of an enzyme produced by genetic variation at the locus coding for that enzyme. amino acids Chemicals which form the basic building blocks of proteins. anadromous Descriptive of a species which spawns and reproduces in fresh water but spends some or much of its adult life at sea. anaphase The phase of mitosis or meiosis during which chromosomes migrate to opposite poles of the spindle and separate to daughter cells. androgen In genetics, an individual whose chromosomes come only from its male parent (alternatively, a masculinising hormone). aneuploid Possessing a number of chromosomes which is not an exact multiple of the haploid chromosome number. annealing The pairing up of single strands of DNA which have complementary sequences. In the case of polymerase chain reaction, this is where the primers join to their complementary sequences on the template DNA. antibodies Immunoglobulin molecules which are produced in the blood of vertebrates in response to foreign proteins. antigenic determinants Sites on the exterior of proteins which initiate the production of antibodies in the blood of vertebrates. antiserum Serum (blood with the cells removed) which contains antibodies to a specified protein. autoradiography The process of exposing a photographic negative to identify the position of very small quantities of radioactively labelled DNA. autosomes Chromosomes which are not sex chromosomes. bacterial artificial chromosome (BAC) A large DNA construct in a plasmid used for transforming and cloning in bacteria, usually E. coli.