Lecture_10_-_Quantitative_Genetics_-_Ch_21-1

Lecture_10_-_Quantitative_Genetics_-_Ch_21-1 - Lecture 10...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 10 Lecture 10 Quantitative Genetics Quantitative Genetics (6 (6 th th Ed. – Ch 21) Ed. – Ch 21) (5 (5 th th Ed. – Ch 6) Ed. – Ch 6)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Quantitative Traits Quantitative Traits Many traits do not fall into small numbers of distinct phenotypes Examples are growth traits such as body weight, height, reproductive ability, general vigor and fitness, production of economically important products such as milk production, egg production, grain yield, wool production, running speed, intelligence, behavior, etc. These traits exhibit continuous variation
Background image of page 2
Quantitative Traits Quantitative Traits Variation is simply defined as differences among individuals in a population for a particular trait or characteristic Continuous variation is described as small differences in phenotypes among individuals in a population One phenotype seems to blend imperceptibly into another phenotype Very difficult to define distinct phenotypes This is also called quantitative variation
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Quantitative Traits Quantitative Traits Quantitative variation is caused by two underlying factors: 1. Quantitative traits are influenced by a large number of genes 1. Quantitative traits are influenced by a large number of environmental effects
Background image of page 4
Quantitative Traits Quantitative Traits Each gene or more specifically, each allele affecting a quantitative trait adds a small component to the overall phenotype for the trait The effect of a single allele on the phenotype for a trait is called an allelic effect or an additive effect . Additive effects are effects that add to the phenotype
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Quantitative Traits Quantitative Traits Individual alleles at individual loci are passed from one generation to the next through the process of meiosis during gamete formation These effects, called additive effects , are passed from one generation to the next because the alleles that cause them are passed from one generation to the next
Background image of page 6
Quantitative Traits Quantitative Traits Differences in the environments to which individuals are exposed also add small components to the overall phenotype for a trait Suppose we have two fields of corn grown side by side using the same variety of corn, the same soil type and the same weather conditions Suppose fertilizer is applied to one field and not
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 05/07/2011 for the course DARY 2072 taught by Professor Hay during the Spring '09 term at LSU.

Page1 / 26

Lecture_10_-_Quantitative_Genetics_-_Ch_21-1 - Lecture 10...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online