Inheritance Beyond One-Gene Models — Drills · Grade 10 Science
Chapter: DNA, Inheritance & Gene ExpressionWhat these drills covers
By the end of Inheritance Beyond One-Gene Models you should be able to:
- I can distinguish complete dominance, incomplete dominance, and codominance.
- I can explain why many traits require several genes and environmental factors.
2 questions, written answer, each with a worked explanation.
Vocabulary used: incomplete dominance, codominance, polygenic trait.
Problem 1
What does a Punnett-square prediction need to be useful?
Answer and explanation
Known parental genotypes and an explicit inheritance model, with probabilities rather than guaranteed outcomes.
Problem 2
Give an example of why phenotype may depend on more than genotype at one locus.
Answer and explanation
A polygenic trait depends on several loci, and conditions such as nutrition can affect growth. One genotype does not specify every phenotypic detail.