Individual having a pair of homologous chromosomes with identical alleles for a certain characteristic.
homozygous
Genetic cross involving only one contrasting characteristic.
monohybrid cross
Cells which fuse to form a zygote.
gametes
Change in the chemical structure of a gene.
gene mutation
XX and XY sex chromosomes which are responsible for the inheritance of sex.
gonosomes
44 ordinary homologous chromosomes in the body cells of man.
autosomes
Observable appearance of an organism.
phenotype
Genetic constitution of an organism.
genotype
Position of a gene on a chromosome.
locus
Alternative forms of a gene occupying the same locus on homologous chromosomes.
allele
Having only one set of chromosomes.
haploid
Small portion oof DNA that controls a single characteristic..
gene
Law that states that genes sort themselves out independently during gamete formation.
Mendel’s Law of Independent Assortment
All the genes contained by a specified population.
gene pool
Offspring of two genetically dissimilar individuals.
hybrid
Full set of chromosomes with all the genes of an organism.
genome
Blood-clotting disorder, occurring mainly in males, that is linked to a recessive gene on the X chromosome.
haemophilia
Human genetic condition resulting from having an extra chromosome 21.
Down’s Syndrome/Trisomy 21
Inherited recessive condition which is characterised by a lack of melanin of the eyes, skin and hair.
albinism
Having two sets of chromosomes, one from each parent.
diploid
