Question 1

What is monohybrid inheritance in the context of Edexcel GCSE Biology?

Accepted Answer

Monohybrid inheritance refers to the study of how a single trait, controlled by one gene with two alleles, is passed from parents to offspring. In Edexcel GCSE Biology, students learn how to predict the inheritance patterns of such traits using tools like Punnett squares.

Question 2

How do you use a Punnett square to predict monohybrid inheritance?

Accepted Answer

A Punnett square is a grid used to predict the genotypes of offspring from a genetic cross. For monohybrid inheritance, you place the alleles of one parent across the top and the alleles of the other parent down the side. By filling in the grid, you can determine the possible genotypes and phenotypes of the offspring.

Question 3

What is the difference between genotype and phenotype in monohybrid inheritance?

Accepted Answer

In monohybrid inheritance, genotype refers to the genetic makeup of an organism, specifically the combination of alleles it possesses for a particular trait. Phenotype, on the other hand, is the observable characteristic or trait that results from the genotype. For example, if the trait is flower color, the genotype might be 'Rr' and the phenotype could be red flowers.

Question 4

What are dominant and recessive alleles in monohybrid inheritance?

Accepted Answer

In monohybrid inheritance, a dominant allele is one that expresses its trait even if only one copy is present, while a recessive allele only expresses its trait when two copies are present. For example, if 'R' is a dominant allele for red flowers and 'r' is a recessive allele for white flowers, a plant with 'Rr' genotype will have red flowers.

Question 5

Can you explain the concept of homozygous and heterozygous in monohybrid inheritance?

Accepted Answer

In monohybrid inheritance, an organism is homozygous if it has two identical alleles for a trait, such as 'RR' or 'rr'. It is heterozygous if it has two different alleles, such as 'Rr'. Homozygous organisms will consistently pass on the same allele to their offspring, while heterozygous organisms can pass on either allele.

Monohybrid Inheritance

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