Which of the Following Could Be Regarded as a Threshold

Question

Which of the following could be regarded as a threshold trait?
A) Cleft lip
B) Schizophrenia
C) Bipolar disorder
D) Cleft lip and Schizophrenia
E) All of these

Accepted Answer

Threshold traits are those that can be influenced by multiple genes and environmental factors, and they typically manifest only when a certain threshold of genetic and environmental risk factors is surpassed. Cleft lip, schizophrenia, and bipolar disorder all fit this description, as they are complex traits influenced by multiple genetic and environmental factors.