Which statement best describes a polygenic trait? (1 point) A polygenic trait is only controlled by multiple
environmental factors.
A polygenic trait is controlled by multiple genes and influenced by the environment.
A polygenic trait is only controlled by one gene and influenced by the environment.
A polygenic trait is only controlled by one environmental factor.
A polygenic trait is controlled by multiple genes and influenced by the environment.
IQ is determined by: (1 point)
multiple genes only
multiple genes and environmental factors both a single gene and environmental factors a single gene only
IQ is determined by multiple genes and environmental factors both.
Which statement is true? (1 point)
Mendelian traits cannot be shown on a bell curve. Hair color and IQ are examples of Mendelian traits. Mendelian traits follows a normal distribution. Mendelian traits are controlled by multiple genes.
The statement "Mendelian traits cannot be shown on a bell curve" is true.
Use the paragraph to answer the question.
The condition phenylketonuria, or PKU, is caused by the toxic buildup of the amino acid phenylalanine, which is found in all proteins and even some artificial sweeteners. The build up in the blood affects nerve and brain development. PKU is caused by a mutation in a gene that affects the breakdown of phenylalanine. When foods that contain phenylalanine are removed from the diet, the effects of PKU are reduced.
Which statement is true about expressed traits of PKU and environmental factors?
(1 point)
Blood circulation problems are a trait in PKU patients caused by the environmental factor of eating phenylalanine foods.
Nerve and mental problems are a trait in PKU patients caused by the environmental factor of eating phenylalanine foods.
Blood circulation problems are an expressed trait of the PKU mutation regardless of environmental factors.
Nerve and mental problems are an expressed trait of the PKU mutation regardless of environmental factors.