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Among humans, if one parent is intelligent (presumably a dominant trait), are the children guaranteed to be intelligent?

Or if one parent is tall (also presumably a dominant trait), are the children guaranteed to be tall?

If not, what are the other factors that determine inheritance of dominant traits like intelligence and height?

User RTB
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Final answer:

Children are not guaranteed to inherit intelligence or tallness from one parent with these dominant traits due to the complexities of polygenic inheritance and environmental factors. A dominant allele's presence does not ensure the trait's expression, as environmental conditions can influence the manifestation of genetic potentials.

Step-by-step explanation:

Understanding the Inheritance of Traits

Even if one parent is intelligent or tall, which are considered dominant traits, children are not guaranteed to inherit these characteristics. In humans, intelligence and height are complex traits influenced by multiple genes (polygenic inheritance), and factors such as environment, nutrition, and education also play critical roles.

Inheritance Patterns

When it comes to inheritance, a child receives one allele for each gene from each parent. If a parent is heterozygous for a trait (possessing one dominant and one recessive allele), there is a 50% chance that they will pass on the dominant allele to their offspring, but also a 50% chance to pass on the recessive allele. Thus, the presence of a dominant allele does not always result in the manifestation of the dominant trait.

Genetic and Environmental Factors

Studies, such as the Minnesota Study of Twins Reared Apart, have indicated that there is a genetic component to intelligence, but environmental influences also significantly contribute to an individual's cognitive development. Similarly, height is influenced by genetics, but factors like diet and health can also affect an individual's stature.

In conclusion, while genetics certainly lay the foundation for traits like intelligence and height, they are not the solitary determinants. It is the interplay of both genetic predisposition and environmental conditions that ultimately shape these characteristics in an individual.

User Joeblog
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