Genetic Crosses And Heredity Flashcards
What are gametes?
Gametes are haploid cells that are capable of fusion
What is fertilisation?
Fertilisation is the union of two gametes to form a single cell called a zygote
What are alleles?
Alleles are different (or alternative) forms of the same gene
What is the locus of a gene?
The locus of a gene is it’s position on a chromosome
What is meant by dominant?
Dominant means the allele that prevents the recessive allele from being expressed
What is meant by recessive?
Recessive means the allele is prevented from being expressed by a dominant alle
What is a genotype?
Genotype means the genetic make-up of an organism, i.e. the genes that are present
What does phenotype mean?
Phenotype means the physical make-up, or appearance, of an organism
Define progeny.
Progeny refers to offspring that are produced
Define homozygous.
Homozygous means that two allele are identical
Define heterozygous
Heterozygous means that the alleles are different
What is a Punnett square?
A grid used to show the ratio of the genotypes of the progeny in a genetic code
What is incomplete dominance?
2
Incomplete dominance means that 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
What is a pedigree?
A pedigree is a diagram showing the genetic history of a group or related individuals
What is the law of segregation (Mendel’s first law)?
2
Inherited characteristic are controlled by pairs of alleles
These alleles segregate (or separate) from each other at gamete formation, with only one member of the pair being found in each gamete
