Exam 1

Question 1

Temperament in horse is relatively lowly heritable (h2=2.5-3.0%) and does not significantly affect the behavior of the horse.

Answer 1

True

Question 2

The female tail line refers to the first three females on the bottom side (dam) of the pedigree.

Answer 2

True

Question 3

Draft mares are commonly used for embryo transfer because of the genes they can pass to the foal

Answer 3

False

Question 4

Using embryos transfer could increase the number of foals per mare each year which could increase genetic progress

Answer 4

True

Question 5

Horses have a long generation interval relative to other species

Answer 5

True

Question 6

A longer generation interval will decrease the rate at which you can make genetic progress

Answer 6

True

Question 7

Genetic variation in a population typically follows a bell shaped distribution curve.

Answer 7

Tf

Question 8

As far as making genetic progress, you want to select sires and dams that fall plus or minus 3 S.D. (Top 2.5%) from the mean

Answer 8

Tf

Question 9

Relative to selection pressure, as you increase the number of traits selected for you decrease genetic progress.

Answer 9

Tf

Question 10

Coat color is an example of a non-functional trait which has been used to make breeding decisions

Answer 10

False

Question 11

If the heritability for reproductive traits is 10% then the environment accounts for 90% of the variation we see in this trait.

Answer 11

True

Question 12

According to the data, the h2 for race time increases as you decrease the length of the race.

Answer 12

True

Question 13

According to the data, the genetic correlations for race time between dirt and turf races are high and are increased as you increase the length of the race.

Answer 13

False

Question 14

An example of an additive gene expression is when angle of the shoulder affects the stride length

Answer 14

True

Question 15

The heritability of speed is much higher than for indexes such as cutting ability as measured by score, rank or earnings

Answer 15

True

Question 16

According to heritability estimates for temperament there is a good chance that mares can pass on behavioral characteristics to their offspring

Answer 16

True

Question 17

Nicking refers to how certain sires cross with dams of specific sire lines

Answer 17

True

Question 18

The four most influential sires in cutting, racing, halter and pleasure all trace back to three bars (TB)

Answer 18

True

Question 19

Top cutting, reining, working cow

Answer 19

Doc Bar

Question 20

Top racing sire

Answer 20

Dash for Cash

Question 21

Top halter sire

Answer 21

Kid Clu

Question 22

Top pleasure sire

Answer 22

Zippo Pine Bar

Question 23

According to data presented in class cutting horses had the highest level of inbreeding

Answer 23

True

Question 24

Lowest level of inbreeding

Answer 24

Pleasure

Question 25

GBED

Answer 25

Glycogen branching enzyme deficiency disorder - always fatal - causes muscle weakness

Question 26

AQHA 5 panel genetic test

Answer 26

GBED- Glycogen Branching Enzyme Deficiency Disorder HERDA- Hereditary Equine Regional Dermal Asthenia Disorder HYPP- Hyperkalemic Periodic Paralysis Disorder MH- Malignant Hypothermia Disorder PSSM- Polysaccharide Storage Myopathy Disorder

Question 27

HERDA

Answer 27

Hereditary Equine Regional Dermal Asthenia Disorder - autosomal recessive - skin splits from layer underneath - traces back to Poco Bueno

Question 28

HYPP

Answer 28

Hyperkalemic Periodic Paralysis Disorder - autosomal dominant - mutation in sodium channel - muscle contraction - Traces back to Impressive

Question 29

MH

Answer 29

Malignant Hyperthermia Disorder - autosomal dominant - triggered by anesthetic halothane, muscle relaxant succinylcholine and stress

Question 30

PSSM

Answer 30

Polysaccharide Storage Myopathy Disorder - mutation in glycogen synthase 1 (GYS1) - tying up - excessive sugar in muscle