Question 1

What is the difference between complete dominance and incomplete dominance in Inheritance II?

Accepted Answer

In complete dominance, the dominant allele completely masks the effect of the recessive allele in heterozygous individuals. In contrast, incomplete dominance occurs when the phenotype of heterozygous individuals is an intermediate of the phenotypes of the homozygous individuals. This means neither allele is completely dominant over the other, resulting in a blended phenotype. Understanding these concepts is crucial for students studying the Singapore Curriculum in Biology.

Question 2

How does codominance differ from incomplete dominance in genetic inheritance?

Accepted Answer

Codominance is a form of inheritance where both alleles in a heterozygous individual are fully expressed, leading to a phenotype that shows both traits simultaneously. An example is the AB blood type in humans, where both A and B alleles are expressed. In contrast, incomplete dominance results in a blended phenotype. These concepts are important in the Singapore Curriculum for understanding complex inheritance patterns.

Question 3

What role do multiple alleles play in inheritance patterns?

Accepted Answer

Multiple alleles refer to the presence of more than two alleles for a genetic trait within a population. Although an individual can only inherit two alleles (one from each parent), the presence of multiple alleles increases genetic diversity. A classic example is the ABO blood group system in humans. This concept is part of the Singapore Curriculum in Biology, helping students understand the complexity of genetic inheritance.

Question 4

Can you explain the concept of polygenic inheritance and its significance?

Accepted Answer

Polygenic inheritance involves multiple genes contributing to a single trait, resulting in a continuous range of phenotypes. Traits such as height, skin color, and eye color are examples of polygenic inheritance. This concept is significant as it explains the variation seen in populations and is a key topic in the Singapore Curriculum for Biology students studying inheritance patterns.

Question 5

Why is understanding sex-linked inheritance important in the study of genetics?

Accepted Answer

Sex-linked inheritance refers to genes located on sex chromosomes, often leading to traits that are more common in one sex. For example, color blindness and hemophilia are more prevalent in males due to the X-linked recessive pattern. Understanding sex-linked inheritance is crucial for students in the Singapore Curriculum as it provides insights into how certain genetic disorders are passed down through generations.

Inheritance II

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