Chapter 28: Quantitative Genetics

Question 1

quantitative genetics

Answer 1

study of complex traits: those that vary measurably, are influenced by the environment and governed by many genes
ex. height, blood glucose levels, blood pressure, metabolism rate, milk production, litter size

Question 2

reasons to study

Answer 2

most key characteristics considered by plant and animal breeders are quantitative traits
many human diseases
many traits that allow a species to adapt to its environment

Question 3

quantitative trait

Answer 3

any trait that varies measurably in a given species
Influenced by genetics and environment
exhibit a continuum of variation
easily measured and described numerically

Question 4

categories of quantitative traits

Answer 4

anatomical: heigh, weight, degree of pigmentation
physiological: metabolic, speed, milk production
behavioral: mating calls, courtship rituals
diseases: cancer, diabetes, arthritis

Question 5

Discontinous traits

Answer 5

Fall into discrete categories
Qualitative
Red vs white eyes, long vs short fur

Question 6

frequency distribution

Answer 6

trait is divided arbitrarily into a number of discrete phenotypic categories
ex. measure height in inches
normal distribution is a bell curve

Question 7

mean (X bar)

Answer 7

mean = sum of all values in group / number of individuals in group

Question 8

variance

Answer 8

common way to evaluate variation within a population