Unit Test — Unit test Answers

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Unlike animal breeders and human geneticists, plant breeders rarely use pedigree charts in their work. Which is most likely the reason that plant breeders use other methods for analyzing results instead of constructing pedigree charts?

A
Plants have many more offspring than most animals have.
B
Plants have too many important traits to show in a pedigree.
C
Plants change only through mutation, not breeding.
D
Plants change too much in each generation to show in a pedigree.
3

Kip studies flower color in petunias, where the allele for red flowers, R, is dominant to the allele for white flowers, r. If Kip makes the cross RR x rr, the gametes that are produced

A
will all carry the r allele.
B
will all carry the R allele.
C
by one parent will carry R and by the other parent will carry r.
D
by one parent will carry Rr and by the other parent will carry rR.
4

Pedigree charts use shaded symbols to show organisms that have a particular trait, such as a defective gene, being traced in the chart. A breeder wants to make a pedigree chart of several generations of horses to avoid breeding males that have a defective gene. What symbol would the horse breeder use to show a male who is affected by a defective gene?

A
shaded circle
B
shaded square
C
unshaded circle
D
unshaded square
5

Which is an example of hybridization that would increase hybrid vigor?

A
producing a litter of puppies by mating two dogs of different breeds
B
using genetic engineering to insert a gene for vitamin A in carrot plants
C
pollinating the flowers on a tomato plant with pollen from a plant of the same variety
D
choosing a mate for a purebred cat from another litter of offspring from the same mother and father
6

Certain breeds of pets have weaknesses and live shorter lives because of

A
inbreeding.
B
reproduction.
C
genetic diversity.
D
natural selection.
7

The pedigree chart below shows the inheritance of a genetic disorder in three generations of one species of insect. Shaded shapes represent individuals that have the disorder.Which mates are least likely to produce offspring that have the disorder?

Question illustration
A
male 1 and female 2
B
male 3 and female 4
C
male 5 and female 6
D
male 9 and female 10
8

Which is an example of selective breeding?

A
Planting peas in a garden one year and planting green beans the next year to enrich the soil.
B
Transferring pollen from flowers on one pea plant to flowers on another pea plant.
C
Comparing pea plants that have white flowers to green bean plants that have white flowers.
D
Grinding the peas from a pea plant into flour to create new food products.
9

Which was the most important contribution to society from the early selective breeder Luther Burbank?

A
an increased world food supply
B
more prize-winning rose varieties
C
a better understanding of devastating diseases
D
many kinds of vegetables related to wild mustard
10

The pedigree chart below shows the inheritance of a genetic trait in a line of sheep.If sheep 7 was to have offspring, in which generation would the offspring be?

Question illustration
A
first
B
second
C
third
D
fourth

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