Chapter 16 - Genetic Crosses and Heredity Flashcards
Gametes
Haploid cells that are capable of fusion
Fertilisation
Union of two gametes to form a single cell called a zygote
Alleles
Different forms of the same gene
Locus
The locus of a gene is it’s position on a chromosome
Dominant
The allele that prevents the recessive allele from being expressed
Recessive
The allele is prevented from being expressed by a dominant allele
Genotype
The genetic make up of an organism (the genes that are present)
Phenotype
The physical make up or appearance of an organism
Progeny
The offspring that are produced
Homozygous
Two alleles are identical
Heterozygous
The alleles are different
Punnet square
A grid used to show the ratio of the genotypes of the progeny in a genetic cross
Incomplete dominance
Neither allele is dominant or recessive with respect to the other. Both alleles are equally expressed in the heterozygous genotype to produce an intermediate phenotype
Pedigree
A diagram showing the genetic history of a group of related individuals
Law of segregation
Inherited characteristics are controlled by pairs of alleles. These alleles segregate from each other at gamete formation, with only one member of the pair being found in each gamete
