Genetic crosses and heredity Flashcards
Gametes
Haploid cells that are capable of fusion
Somatic cells
All cells except for reproductive cells
Fertilisation
Union of two gametes to form a single cell called zygote
Allele
Different forms of the same gene
Locus
Position on a chromosome
Genotype
Genetic make up of an organism
Phenotype
Physical make up/ apperarance
Progeny
Off spring produced
Homozygous
Two alleles are identical
Heterozygous
Alleles are different
Punnett square
Gird used to show the ratio of genotypes of the progeny
Dominant
Prevents recessive allele from being expressed
Recessive
Prevented from being expressed by dominant
Incomplete dominance
Neither allele is dominant or recessive and both are equally expressed. Heterozygous phenotype produces an intermediate phenotype
Pedigree studies
Diagram showing the genetic history of related individuals
Autosomes
Non-sex chromosomes
The law of segregation
during gamete formation each member of the allelic pair separates from the other member to form the genetic constitution of the gamete
The law of independent assortment
the alleles of two (or more) different genes get sorted into gametes independently of one another. In other words, the allele a gamete receives for one gene does not influence the allele received for another gene.
Linkage
Genes are located on the same chromosome
Sex linkage
Characteristics is controlled by a gene on a sex chromosome usually X
