What factors cause quantitative variation in a trait within a population?

Mendel's theory of inheritance __________.

A single genetic locus that controls more than one trait is said to be __________.

In people with sickle-cell disease, red blood cells break down, clump, and clog the blood vessels. The blood vessels and the broken cells accumulate in the spleen. These events lead to physical weakness, heart failure, joint pain, and brain damage. Such a suite of symptoms can be explained by __________.

Is a round yellow pea seed (genotype RrYy) an example of polygenic inheritance? Why or why not

A quantitative trait .a. may be one that is strongly influenced by the environment;b. varies continuously in a population;c. may be influenced by many genes;d. is not either off or on;e. all of the above

When graphing the phenotypes of a trait controlled by many genes and the environment, the line showing the frequency of each phenotype resembles .a. a horizontal, straight line;b. a vertical, straight line;c. the letter T;d. a bell shape;e. a circle

Skin color in humans is at least partially hereditary; dark-skinned parents tend to have dark-skinned children. But humans come in a range of skin tones. Which extension of Mendel's model accounts for the hereditary variation in human skin color?