Inheritance, characteristics of offspring

Explain the term homozygous

Having two identical alleles on homologous chromosomes could be dominant or recessive.

Explain the term heterozygous

Having two different alleles on homologous chromosomes.

Explain the term genotype

Genetic information carried by an individual.

Explain the term phenotype

Observable characteristics of the individual - the way the genotype is expressed.

Explain the term autosomal

Autosomal inheritance is the transmission of traits carried on autosomes.

Explain the term sex-linked

Sex-linked inheritance is the transmission of traits carried on the sex chromosomes (X chromosome).

Explain the term dominant

The allele that masks the recessive allele when both a dominant and recessive allele are present.

Explain the term recessive

The allele that is masked or hidden by the dominant allele in the heterozygous condition.

Explain the term gene

A section of DNA/chromosome that carries genetic code for a particular characteristic or trait.

Explain the term allele

Different forms of the same gene.

Explain the term progeny

a descendant of a person

Recessive

Unaffected parents have unaffected child – ‘skips a generation’

Recessive Autosomal

Affects males and females equally

Recessive x-linked

More common in males, Affected daughters must have affected father, Affected mothers will pass on to all sons.

Dominant

Every affected individual has an affected parent – does not ‘skip a generation’.

Dominant autosomal

Affects males and females equally, Fathers can pass onto sons

Dominant x-linked

More common in females, Affected fathers cannot pass onto sons but will have affected daughter.