Mutations
Probability
Quantitative traits
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New Material
100

True or False: nondisjunction occurs more often in males than females 

false
100

Define mean and provide the equation for solving for it 

A measure of central tendency

100
  1. Quantitative characteristics often exhibit a _________________ distribution 

normal 

100

What is the equation used to find how many chromosomes would be found in monosomy, trisomy, and allotriploid? Solve for a diploid individual with

 2n = 36 

2n-1 =35

2n+1 =37

3n = 54

n=18

100

Genetic correlations between traits can be positive or negative. In a population of chickens, the genetic correlation between body weight and egg production is -0.20.  If an increase in egg production is selected for in this population, what will be the effect on chicken body weight?

body weight will increase

body weight will decrease

there will not be an effect on body weight

this question cannot be answered without knowing the heritability of the two traits

Body weight will decrease

200

What type of mutation is occurring in the chromosome segment below:


A B C D E F G -----> A B C D G F E 


inversion 

200

Define variance and supply the equation for solving for it

A measure of the width of the distribution.

200

In a watermelon population, the number of seeds is determined by four genes (A, B, C, and D genes) of equal effect that act additively. A dominant allele contributes 30 seeds, and a recessive allele contributes 10 seeds. In this population, watermelons with genotypes AabbCcDd and aaBbCcDD have the same number of seeds.

False

200

Species I has 2n = 42 chromosomes and species II has 2n = 38. How many chromosomes would be found in an allotriploid of these species?

59 or 61

200

A rancher determines that the average amount of wool produced by sheep in her flock is 15 kg per year.  In an attempt to increase the wool production in the flock, she picks 5 male and 5 female sheep with the highest wool production; the average amount of wool produced per sheep by those selected is 25 kg per year.  She interbreeds these selected sheep and finds that the average wool production among the progeny of the selected sheep is 22 kg per year.

What is the selection differential for wool production?

10 kg

300

When a deletion chromosome pairs with a normal chromosome during prophase I, it is the deletion chromosome that loops out.

False 

300

5 caterpillars were measured. Their lengths (in cm) were 

7, 9, 6, 11, 8

Calculate the mean

8.2 cm

300

The number of spots on a ladybug is determined by 7 independent alleles. The dominant allele contributes 1 spot and the recessive contributes 0 spots. How many F2 ladybugs would you expect to need to see one lady bug with no spots 

16,384

300

Which of the following traits shows a larger narrow sense heritability?


Trait 1

300

A rancher determines that the average amount of wool produced by sheep in her flock is 15 kg per year.  In an attempt to increase the wool production in the flock, she picks 5 male and 5 female sheep with the highest wool production; the average amount of wool produced per sheep by those selected is 25 kg per year.  She interbreeds these selected sheep and finds that the average wool production among the progeny of the selected sheep is 22 kg per year.

What is the response to selection for wool production?

7

400
Nondisjunction occurs in Meiosis 2. What are the all possible zygotes that may be formed after fertilization?

Trisomic, monosomic, normal diploid 

400

5 caterpillars were measured. Their lengths (in cm) were 

7, 9, 6, 11, 8

Calculate the variance 

3.7

400

Bat wingspan is determined by 6 genes. Bats that are homozygous for all recessive alleles have a wingspan of 3 in. Bats that are homozygous for all dominant alleles have a wingspan of 6 in. What is the wingspan of a bat with the genotype AaBBCcDdEEff?

4.75 in 

400

The phenotypic variance for an outbred strain of frogs is 634. The phenotypic variance for an inbred strain of frogs is 271. What is the broad sense heritability and interpret the value.

0.57

400

A rancher determines that the average amount of wool produced by sheep in her flock is 15 kg per year.  In an attempt to increase the wool production in the flock, she picks 5 male and 5 female sheep with the highest wool production; the average amount of wool produced per sheep by those selected is 25 kg per year.  She interbreeds these selected sheep and finds that the average wool production among the progeny of the selected sheep is 22 kg per year.

What is the narrow sense heritability for wool production in this flock?

0.7
500

In one species of dogs, chromosome I has the segments ABCDEFG and chromosome V has the segments LMNOPQR. If one dog of this species has chromosomes ABCDPQR and LMNOEFG, what type of mutation occurred?

reciprocal translocation 

500

5 caterpillars were measured. Their lengths (in cm) were 

7, 9, 6, 11, 8

Calculate the standard deviation 

1.92

500

Tomato weight is determined by 2 independently assorting loci. The dominant allele contributes 3 g to plant weight and the recessive allele contributes 0.5 g. What will be the most frequent weight of tomatoes in the F2 generation?

7g

500

The broad sense heritability of bat’s wing span was calculated to be 0.45. If the phenotypic variance was 273, what is the genetic variance?

122.85

500

After multiple generations of selection for increased wool production in her flock, in generations 20 and 21 of selection the rancher notices that there is no response to selection. She is getting tired of shearing sheep, anyway, so she decides to try two generations of selection for decreased wool production ("reverse selection"). She is surprised when she does not see a response to this reverse selection. What is the most likely explanation for the lack of response to selection for either increased or decreased wool production?

There is no genetic variation remaining for wool production in the flock

There is no environmental variation remaining for wool production in the flock

There is a negative correlation between wool production and sheep survival (increase in wool production is correlated with a decrease in sheep survival)

There is a positive correlation between wool production and sheep survival (increase in wool production is correlated with a increase in sheep survival)

There is no genetic variation remaining for wool production in the flock

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