Explain monohybrid inheritance using genetic diagrams, Punnett squares and family pedigrees Flashcards – Edexcel Level 1/Level 2 GCSE (9–1) in Biology (1BI0) (Higher)

What does a monohybrid cross predict, and how?

It predicts inheritance of one characteristic by combining the alleles each parent can pass on to find possible offspring genotypes.

How does a Punnett square show possible offspring genotypes?

Possible parental alleles are placed along the edges; each cell shows a possible offspring genotype.

How are offspring genotypes used to find a phenotypic ratio?

Use the genotypes to predict the offspring phenotypes, then calculate their ratio.

With one dominant and one recessive allele, what phenotypic ratio is predicted from crossing two heterozygous parents?

3:1 dominant to recessive.

With one dominant and one recessive allele, what phenotypic ratio is predicted from crossing a heterozygous parent with a homozygous recessive parent?

1:1 dominant to recessive.

What does a pedigree diagram show about a family characteristic?

Which family members show or lack the characteristic across generations.

How are individuals and family relationships represented in a pedigree?

By connected symbols.

How can a pedigree be used to interpret a characteristic’s inheritance pattern?

Trace the characteristic from parents to offspring through successive generations.