Genetic Variation Definitions Flashcards
Allele
Different forms of a gene due to slightly different order of bases
Allele Frequency
Is a measure of the relative frequency of an allele on a genetic locus in a population
Asexual Reproduction
Reproduction involving only one parent. Doesn’t produce genetic variation
Chiasma
Point of contact, the physical link, between two (non-sister) chromatic belonging to homologous chromosomes during crossing over
Co-Dominance
Heterozygous individuals have a phenotype that shows the penhenotype of both parents
Complete Dominance
A form of dominance in heterozygous condition where in the allele that is regarded as dominant completely masks the effect of the allele that is recessive
Crossing Over
Occurs during Meiosis, when the homologous chromosomes line up at the equator, sometimes they tangle, snap, and exchange genetic information
Diploid
A cell or organism consisting of two sets of chromosomes: usually, on set from the mother (maternal) and another set from the father (paternal)
Evolution
Is the change in the characteristics of a species over several generations and relies on the process of natural selection
Fertilisation
A process in sexual reproduction that involves the union of male (sperm) and female (ovum) gametes (each with a single, tabloid set of chromosomes) to produce a diploid zygote
Founder Effect
Is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population
Gamete
Sex cell of an organism
Gametic Cells
Sex cells. Cells with half the chromosome number. If a mutation occurs in one of these cells and that cell results in a zygote, all cells in the offspring will have that mutation
Gene
A length of DNA which codes for a specific protein and therefore codes for a particular characteristic
Gene Pool
Refers to the total number of genes of every individual in a population
Genetic Diversity
The total number of genetic characteristics in the genetic makeup of a species
Genetic Drift
Is the change in the frequency of an existing gene variant (Allele) in a population due to random chance alone and not natural selection
Genotype
The genetic make-up of the organism
Haploid
When a cell has half the usual number of chromosomes
Heterozygous
Different forms of the allele are present in the genotype e.g. Hh
Homologous Chromosomes
Chromosome pairs (one from each parent) that are similar in length, gene position, and centromere location they contain. The position of the genes on each homologous chromosome is the same. However, the genes may contain different alleles
Homozygous
The same form of the allele is present in the genotype e.g. hh or HH
Incomplete Dominance
Heterozygous individuals have a phenotype that is intermediate between the two homozygous phenotypes (like a bland)
Independent Assortment
The random arrangement of homologous chromosomes during Meiosis that results in gametes with unique combinations of alleles
