In a genetic cross using a Punnett square, what is the null hypothesis for the expected genotype ratios?

• A. The observed genotype ratios will match the expected ratios based on Mendelian inheritance.
• B. The observed phenotype ratios will differ significantly from the expected ratios.
• C. The observed genotype ratios will be completely random and unpredictable.
• D. The observed phenotype ratios will match the expected ratios based on environmental factors.

Answer: (A)

Verified step by step guidance

1. Understand the concept of a null hypothesis: In genetics, a null hypothesis is a statement that there is no effect or no difference, and it is used as a starting point for statistical testing.
2. Identify the context of the problem: The problem involves a genetic cross using a Punnett square, which is a tool used to predict the genotype and phenotype ratios of offspring from a particular genetic cross.
3. Recall Mendelian inheritance: Mendel's laws of inheritance describe how traits are passed from parents to offspring, predicting specific genotype ratios based on dominant and recessive alleles.
4. Formulate the null hypothesis: In the context of a Punnett square, the null hypothesis would be that the observed genotype ratios will match the expected ratios based on Mendelian inheritance.
5. Consider alternative hypotheses: These might include the observed phenotype ratios differing significantly from expected ratios, or being influenced by environmental factors, but these are not the null hypothesis in this context.