MMC Exam 2

Question 1

If a strong negative change in mature weight is observed along with a strong positive change in meat tenderness then the two traits have a …

Answer 1

Strong negative correlation

Question 2

Which of the following is considered the most important genetic parameter for an individual?

Answer 2

Breeding value

Question 3

Correlation

Answer 3

• Correlation of X and Y is the same as correlation of Y and X
• Unitless
• It only ranges from -1 to 1

Question 4

In a non-random mating system

Answer 4

• Expected proportion of homozygous and heterozygous individuals deviates from HW

Question 5

Inbreeding depression

Answer 5

• Opposite of Heterosis
• Results from poor gene combination value
• Alters gene frequency

Question 6

b (sub xy)

Answer 6

• Is the regression of Y on X
• Variation in trait X influences the variation in trait Y
• There is an assumption of cause and effect

Question 7

Effects of outbreeding will depend on

Answer 7

• Genetic relationship of the parents
• Trait heritability

Question 8

The following are examples of a major or extensive use of crossbreeding except

Answer 8

Crossing two dairy breeds (such as Holstein and Jersey)

Question 9

Environmental Correlation

Answer 9

• Measure of strength of relationship between environmental effects of one trait and another
• They are often used for management purposes

Question 10

Heterosis

Answer 10

-Result from increased heterozygosity
- Gene combinations are not transmitted to the progeny

Question 11

The degree of heterosis in the offspring can be affected by:

Answer 11

• Genetic relationship of the parents
• Heritability value of the trait

Question 12

Assuming the avg birth wgt is a population is 75lbs, the avg weaning wgt in a population is 400lbs, and the phenotypic regression of weaning wgt on birth wgt is 2.75 lbs per lbs. If a calf’s birth wgt is 77lbs, what is the estimated weaning wgt for this calf?

Answer 12

405.5lbs
(Use regression equation
a= y bar - b x bar
y hat = a+bX)