Glossary

These pages will look at the evolution of Apis mellifera and its place in the world. Along the way will be provided some links for further expansion of the subject.

As a general guide Glenn Apiaries website (left) covers much of the basic material which needs to be considered and understood when breeding bees.

info@scientificbeekeeping.co.uk

Here are some definitions to make understanding genetics and bee breeding easier.

Genetics:

Chromosome:

DNA:

Gene:

Allele:

PCR:

Haploid:

Gamete:

Parthenogenesis:

Arrhenotoky:

Thelytoky:

The study of heredity and variation in organisms. Also the genetic makeup and attributes of an organism.

A thread like structure found in the nucleus of a living cell. Chromosomes are made up of DNA and protein combined as chromatin. Each chromosome contains many genes.

Deoxyribonucleic acid, a self-replicating material which is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.

A unit of information held in a chromosome which determines characteristics of the offspring.

A version of a particular gene.

Polymerase chain reaction (PCR) is used in molecular biology to make copies of a specific DNA segment. Thousands of copies of DNA sequences are generated of that particular DNA segment.

Nucleotides:

Submolecules arranged in a sequential order to make up DNA and RNA molecules. There are four types in DNA (T) thymine (in DNA only), (A) adenine, (C) Cytosine and (G) Guanine. T pairs with A and C with G. In RNA there are also four types, three the same : gGuanine (G), Uracil(U) (in RNA only), Adenine(A), and Cytosine(C).

Having one set of chromosomes, seen in honey bees drones who have just 16 single chromosomes. Some will be dominant and some recessive.

Homozygous:

Heterozygous:

The situation when both alleles are identical for any particular gene in a diploid organism.

The situation where the two alleles are different for any particular gene in a duploid organism.

A haploid cell that may fuse with another haploid cell during fertilization in organisms that sexually reproduce, an egg or a sperm. In haploid honey bee drones fertilization of the egg does not occur.

The reproduction from an ovum without fertilization, for example as a normal process in the creation of honey bee drones. Literally "virgin birth'.

A type of parthenogenesis where a male is produced from an unfertilised egg and has no father.

A type of parthenogenesis where a female is produced from an unfertilised egg and has no father. This is seen in Apis mellifera capensis honey bees found in South Africa. They are capable of producing both workers and queens.

Hemizygous:

Having only a single copy of a gene.

Complementary sex determiner (CSD):

The gene that determines the sex of the honey bee. Hemizygous bees develop into males and heterozygous bees become female. The estimated variety of CSD genes has risen from 20 to 80 recently.

A single cell, the result of the fertilisation of a female gamete (egg) by a male gamete (sperm).

Zygote:

Meiosis:

A special type of cell division that reduces the chromosome number by half, creating four haploid cells, each genetically distinct from the parent cell. This process occurs in sexual reproduction of eggs and sperm (a gamete).

Mitosis:

A part of the cell cycle when replicated chromosomes are separated into two new nuclei, giving rise to genetically identical cells in which the number of chromosomes remain the same.

The creation of eggs through meiotic cell division.

Oogenesis:

The creation of sperm through meiotic cell division.

Spermatogenesis:

Diploid:

Having two sets of chromosomes, in honey bee workers and queens 32 in 16 pairs. Some will be dominant and some recessive.

Genetic Recombination:

The exchange of segments of chromosomes during meiosis which leads to the production of offspring with combinations of traits that differ from those found in either parent. AKA "crossing over"

Genotype:

The paired genes in the DNA of the nucleus of a cell which determines one of its characteristics (phenotype)

Phenotype:

The set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.

A genome is an organism's complete set of DNA, including all of its genes. Each genome contains all of the information needed to build and maintain that organism. A copy of the entire genome is contained in all cells that have a nucleus.

Genome:

RNA:

Ribonucleic acid is involved with coding, decoding, regulation and expression of genes. It is a chain of nucleotides and exists as a single-strand folded onto itself, rather than a paired double-strand. It is made up of the nitrogenous bases of guanine (G), uracil(U), adenine(A), and cytosine(C).

Chromatids:

A chromosome that has been newly replicated during mitosis. Generally identical, (homozygous) but if mutation occur,s they will present slight differences, in which case they are heterozygous.

Chiasma:

The point at which two chromatids of a homologous chromosome are linked during meiosis and where an exchange of genetic material may occur. See Genetic Recombination.

Dominance:

Dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome.

F1:

An F1 Hybrid is the first filial generation of offspring of distinctly different parental types. These offspring produce a new, uniform phenotype with a combination of characteristics from the parents. In honey bee breeding the parents can be two inbred lines or they can be from two different subspecies for example, Apis mellifera mellifera and Apis mellifera carnica.

Hybrid:

A hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction.