$$BV = \text{sum of individual allele effects}$$

Question 1

Which of the following best describes the concept of complementarity in Alaskan sled dog breeding?

Accepted Answer

Combining breeds to maximize the strengths of each, such as endurance and speed.

Question 2

In terminal crossbreeding, what is the primary purpose of using a terminal sire?

Accepted Answer

To produce offspring with optimal market traits such as size and growth rate.

Question 3

Which equation represents the genotypic value ($$VG) of an $$individual?

Accepted Answer

$$VG = VA + VD + VI$$

Question 4

What is the effect of inbreeding on fitness in a population?

Accepted Answer

It increases the number of homozygous deleterious recessives, leading to inbreeding depression.

Question 5

Which mating strategy would most likely decrease inbreeding and increase heterozygosity?

Accepted Answer

Crossbreeding

Question 6

Why are inbred animals preferred for sequencing a new genome assembly?

Accepted Answer

They have increased homozygosity, which simplifies the assembly process.

Question 7

Which of the following is a limitation of progeny testing in dairy cattle?

Accepted Answer

It is slow and expensive, requiring years and significant investment.

Question 8

What is heterosis?

Accepted Answer

The increased performance of crossbred offspring compared to the average of their parents.

Question 9

In a single locus with no dominance, what is the relationship between genetic and breeding values?

Accepted Answer

They are equal.

Question 10

Which equation represents the breeding value ($$BV) $$for a single locus with dominant alleles?

Accepted Answer

$$BV = 	ext{sum of individual allele effects}$$

Question 11

What is the primary advantage of rotational crossbreeding in dairy cattle?

Accepted Answer

It maintains hybrid vigor (heterosis) across generations.

Question 12

Which of the following is NOT a reason to use mating strategies that increase inbreeding?

Accepted Answer

To increase hybrid vigor.

Question 13

What is pedigree collapse?

Accepted Answer

When a common ancestor is shared, resulting in fewer distinct ancestors in the pedigree.

Question 14

Which force drives genetic selection in domestic animals?

Accepted Answer

Both natural and artificial selection.

Question 15

Which of the following is an example of artificial selection in domestic animals?

Accepted Answer

Selecting for increased milk production in dairy cows.

Question 16

If allele B confers $$+10g of $$live weight and allele b confers $$-10g$$, what is the genotypic value for genotype Bb with dominance?

Accepted Answer

$$10 + 10 = 20g$$

Question 17

Which factor does NOT affect genotypic and breeding values?

Accepted Answer

The color of the animal's coat.

Question 18

Why does the first generation of a 2-breed cross show the greatest benefit from hybrid vigor?

Accepted Answer

Because it maximizes heterozygosity and combines complementary traits.

Question 19

Which of the following is a plausible reason for using progeny testing in dairy cattle?

Accepted Answer

To estimate traits not expressed in males, such as milk production.

Question 20

In a population where allele frequencies are unequal, what is the effect on the average effect of alleles?

Accepted Answer

The rarer allele has a greater average effect.

Genetic Principles in Animal Breeding: Crossbreeding, Inbreeding, and Genetic Selection

Study Guide - Practice Questions