Food Animal G&D Exam 4

True or False: An increase in extracellular matrix volume can contribute to overall body growth even if cell number remains constant.

True

True or False: The smooth sigmoidal shape of a cumulative growth curve reflects continuous and uniform biological growth at all levels.

False

True or False: A decrease in growth rate after the inflection point is primarily associated with increasing investment in reproductive

development.

True

True or False: Relative growth rate (RGR) can decrease over time even when absolute body weight gain continues to increase.

True

True or False: Tissues that mature earlier contribute more to total body weight gain during the later phases of growth.

False

True or False: Absolute growth rate alone is sufficient to determine whether an animal is in the lag, exponential, or deceleration phase.

False

True or False: Animals at different chronological ages can be at the same physiological stage of growth.

True

True or False: Changes in body composition during growth are independent of the rate at which tissues grow.

False

True or False: An animal showing rapid early growth but reduced final size likely experienced changes in both growth rate and growth duration.

True

Two animals show identical cumulative growth curves until puberty, after which one curve flattens earlier than the other.

Which conclusions are valid?

a) The animals had identical early growth rates

b) The animal with earlier flattening reached maturity sooner

c) The animal with later flattening must have had faster early growth

d) The difference likely reflects variation in growth duration rather than initial growth mechanisms

e) Both animals must have identical final body composition

f) None of the above

a, b, d

True or False: If a trait shows no observable variation within a population, its heritability can still be high if it is genetically regulated.

False

True or False: Specific mutations in one nucleotide sequence can generate genetic variants.

True

True or False: Two animals with identical body weight but different genetic selection histories can differ significantly in fat deposition.

True

True or False: Breed classification emphasizes genetic similarity more strictly than strain classification.

False

True or False: Selection for increased milk production in cattle is expected to positively correlate with muscle mass due to improved nutrient utilization.

False

True or False: At the same chronological age, large-framed animals are physiologically more mature than small-framed animals.

False

True or False: Phenotypic variance can be partitioned into genetic and environmental components, both of which contribute quantitatively to trait variation.

True

A researcher studies a population of cattle where all animals show identical coat color despite having different genetic sequences at multiple loci. The researcher concludes that coat color has high heritability because it is genetically controlled.

Which of the following statements are correct?

a) The researcher’s conclusion about high heritability is correct because the trait is genetically determined

b) Genetic variation may exist even if phenotypic variation is not observed

c) Genetic variance for coat color in this population is effectively zero

d) Selection for coat color in this population would be ineffective

b, c, d

A beef producer compares two groups of cattle:

Group A: Small-framed, early-maturing

Group B: Large-framed, late-maturing

Both groups are evaluated at:

Same age (12 months)

Same live weight (500 kg)

Which of the following statements are correct?

a) After 12 months, Group A will have a higher fat percentage than Group B

b) At 500 kg, Group A will be physiologically older than Group B

c)At 500 kg, Group B will have a higher fat percentage than Group A

d) At the same age, Group B will have a higher bone and muscle proport

a, b, d

True or False: An increase in dressing percentage with age indicates that carcass tissues are growing faster than non-carcass components at later stages of development.

True

True or False: Empty body weight is always a better indicator of economic value than carcass weight because it excludes gastrointestinal contents.

False

True or False: Two animals with identical live weights can have different economic values due to differences in carcass composition.

True

True or False: Absolute growth curves of tissues are bell-shaped because they represent growth rate rather than total accumulation.

True

True or False: Relative growth curves can decrease over time even when the absolute amount of that tissue is increasing.

True

True or False: A leftward shift in a cumulative growth curve indicates that the animal reaches the same body weight at an earlier age.

True

True or False: Comparing animals using chronological age can lead to misleading conclusions when they reach maturity at different ages.

True

True or False: Allometric growth explains why body proportions change during development due to different growth rates of tissues and structures.

True

True or False: Bone, muscle, and fat all increase in absolute amount with age, but their relative proportions change differently.

True

A producer is deciding when to slaughter cattle. Two time points are considered:

Time A: Rapid muscle growth, low fat

Time B: Slower muscle growth, rapid fat accumulation, higher dressing percentage

Which statements support choosing Time B?

a) Dressing percentage is higher, meaning a greater proportion of carcass weight

b) Carcass weight represents economic value better than live weight

c) Fat deposition increases carcass weight even if meat quality may decline

d) Early slaughter always maximizes economic return

a, b, c