Body size in mice is controlled in part by genetics. The following data show the number of mice grouped by lengths:
Length Group Number of Mice
Very small (4-5 cm) 2
Small (5-7 cm) 6
Average (7-10 cm) 15
Large (10-12 cm) 7
Very large (12-13 cm) 1
A bar graph entitled Mouse Body Size in a Population. The Y axis is labeled Length, centimeters. Two mice are very small, between four and five centimeters. Six mice are small in size, between five and seven centimeters. Fifteen mice are medium in size, between seven and ten centimeters. Seven mice have large bodies, between ten and twelve centimeters. One mouse is very large, between twelve and thirteen centimeters.
Identify the inheritance pattern that this trait follows in mice.
(1 point)
Responses
Mendelian
Mendelian
polygenic
polygenic
incomplete dominance
incomplete dominance
complete dominance
1 answer
The inheritance pattern that this trait follows in mice is polygenic.
This conclusion is drawn from the observation that body size in mice is influenced by multiple genetic factors, rather than being determined by a single gene with distinct categories, which would suggest Mendelian inheritance. The continuous range of body sizes and the presence of multiple categories also indicate that many genes contribute to the overall phenotype, characteristic of polygenic traits.
