Flashcards in Quizzes Deck (22):

1

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Following diagrams show two different stages of cell division in a mammalian cell where 2n=6. State the type of cell division (meiosis/mitosis) and which stage of cell division is seen in each pictured cell?

6 chromosomes lined up in the middle of the cell

### Metaphase in mitosis

2

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Following diagrams show two different stages of cell division in a mammalian cell where 2n=6. State the type of cell division (meiosis/mitosis) and which stage of cell division is seen in each pictured cell?

3 homologous pairs of chromosomes being pulled to each pole of the cell by the mitotic spindle

### Anaphase I in meiosis

3

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The following cell is at meiosis anaphase II. What is the diploid chromosome number of this cell?

4 chromatids are being pulled at each pole of the cell by the mitotic spindle

###
n=4

2n=8 (diploid)

4

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Polydactylism is a genetic, autosomal dominant trait where the individual has extra digits on their hands or toes. Mary has the polydactyl trait (she has six toes on her right foot) but her mother was normal. Mary and her partner Ben (normal) are thinking about having children together. Answer the following questions. Show your work and the formula used for calculations.

What are Mary and Ben’s genotypes?

###
Mary: Aa

Ben: aa

5

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Polydactylism is a genetic, autosomal dominant trait where the individual has extra digits on their hands or toes. Mary has the polydactyl trait (she has six toes on her right foot) but her mother was normal. Mary and her partner Ben (normal) are thinking about having children together. Answer the following questions. Show your work and the formula used for calculations.

What are the chances that Mary and Ben’s first child will be polydactyl?

### 50% chance first child will be polydactyl

6

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Polydactylism is a genetic, autosomal dominant trait where the individual has extra digits on their hands or toes. Mary has the polydactyl trait (she has six toes on her right foot) but her mother was normal. Mary and her partner Ben (normal) are thinking about having children together. Answer the following questions. Show your work and the formula used for calculations.

Mary and Ben decide to have 4 children. What is the probability that their first child and the last child will not have the disease?

### 1/4 chance that first and last child are normal

7

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Polydactylism is a genetic, autosomal dominant trait where the individual has extra digits on their hands or toes. Mary has the polydactyl trait (she has six toes on her right foot) but her mother was normal. Mary and her partner Ben (normal) are thinking about having children together. Answer the following questions. Show your work and the formula used for calculations.

If Mary and Ben have 4 children what is the probability that at least 3 of their children will have the disorder?

### 5/16 chance that at least 3 of their children will have the disorder

8

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In morning glory purple flower colour (P) is dominant to white (p), and large leaves (L) is dominant to small leaves (l). A test cross of a double heterozygotic plant produced the following progeny in the following numbers.

82 purple flowers, large leaves

72 purple flowers, small leaves

90 white flowers, large leaves

68 white flowers, small leaves

Give the genotypes of the two plants that were crossed and the expected progeny in this cross. What is the expected phenotypic ratio among the progeny?

### 1 purple flowers, large leaves : 1 purple flowers, small leaves : 1 white flowers, large leaves : 1 white flowers, small leaves

9

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In morning glory purple flower colour (P) is dominant to white (p), and large leaves (L) is dominant to small leaves (l). A test cross of a double heterozygotic plant produced the following progeny in the following numbers.

82 purple flowers, large leaves

72 purple flowers, small leaves

90 white flowers, large leaves

68 white flowers, small leaves

Using a chi-squared test determine whether the data fits the expected model. (Set the critical value at alpha=0.05 and use the Chi squared table). Clearly state your hypothesis and conclusion.

###
Ho: Without significant difference between the observed and expected, the ratio should be 1:1:1:1 as long as P>0.05 (critical value).

0.20 < P < 0.30

Since P > 0.05 (critical value), we fail to reject Ho since it fits the 1:1:1:1 model.

10

## If a female produces 1 in 5000 eggs with an extra X chromosome due to nondisjunction, what is the expected frequency of XXX females (triple X syndrome) arising from any number of fertilized eggs? (Assume meiosis in males is always normal).

### 1/10,000

11

## Could a man with type B blood and a woman with type AB produce a child with type O blood? Explain your answer using a Punnett square.

### No, they could NOT produce a child with type O blood, because the mother does not have the recessive “i.” The father could either be I^B I^B or I^B i

12

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If Duchenne muscular dystrophy (DMD), an X-linked recessive condition in humans has a frequency of 1/10000 females in a hypothetical population.

What is the frequency of males with DMD in this population?

### 0.01 or 1/100 males

13

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If Duchenne muscular dystrophy (DMD), an X-linked recessive condition in humans has a frequency of 1/10000 females in a hypothetical population.

Assuming that the population is in Hardy-Weinberg equilibrium, what percentage of the females in the population are carriers/heterozygotes?

### 1.98%

14

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A randomly mating population has the following genotypic frequencies.

Genotype BB Bb bb

Frequency 0.3 0.25 0.45

Is this population in HW equilibrium?

### No this population is NOT in H-W equilibrium because the frequencies are not the same.

15

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A primrose plant is heterozygous for the following autosomal chromosome. If “.” Represents the centromere.

AB.CDEF

ab.edcf

State the mutation that occurred in the chromosome?

### Paracentric inversion

16

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A primrose plant is heterozygous for the following autosomal chromosome. If “.” Represents the centromere.

AB.CDEF

ab.edcf

Draw the chromosomal pairing that would take place during meiosis prophase I between these two chromosomes (assume crossover occurs between C and D)

### See quiz 2

17

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A primrose plant is heterozygous for the following autosomal chromosome. If “.” Represents the centromere.

AB.CDEF

ab.edcf

What are the possible gamete karyotypes? State whether each gamete is viable or not.

###
*acentric fragment was lost

1. AB.CDEF (viable)

2. AB.C (not viable)

3. ab.ed (not viable)

4. ab.edcf (viable)

18

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In soybean 3 linked genes control three dominant traits tunicates seeds (T), glossy appearance (G) and ligulated stem (L). A test cross was made between a F1 triple heterozygous plant and a homozygous recessive plant. The following phenotypic ratios were observed in the F2 progeny.

Phenotype Number

TGL=56

TGl=126

tgL=120

Tgl=70

tGL=62

tGl=2

TgL=4

tgl=60

Total: 500

Determine the gene order.

### G-T-L or L-T-G (where T is in the middle)

19

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In soybean 3 linked genes control three dominant traits tunicates seeds (T), glossy appearance (G) and ligulated stem (L). A test cross was made between a F1 triple heterozygous plant and a homozygous recessive plant. The following phenotypic ratios were observed in the F2 progeny.

Phenotype Number

TGL=56

TGl=126

tgL=120

Tgl=70

tGL=62

tGl=2

TgL=4

tgl=60

Total: 500

Calculate the genetic distance between these 3 loci and draw the linkage map.

###
G-T cross-over: Rf=27.6mu

T-L cross-over: Rf=24.4mu

Linkage map: G——-27.6mu———T———24.4mu———L

20

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In soybean 3 linked genes control three dominant traits tunicates seeds (T), glossy appearance (G) and ligulated stem (L). A test cross was made between a F1 triple heterozygous plant and a homozygous recessive plant. The following phenotypic ratios were observed in the F2 progeny.

Phenotype Number

TGL=56

TGl=126

tgL=120

Tgl=70

tGL=62

tGl=2

TgL=4

tgl=60

Total: 500

Calculate the coefficient of coincidence and interference.

###
COC=0.178

I=0.822

21

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In Impatiens (Balsam) flower colour is determined by several independently assorting interacting loci. If two true breeding plants, one with red flowers and the other with white flowers were crossed, all the F! Produced plants with purple flowers. A self cross between F1 produced offspring with the following flower colours, 94 purple, 31 red, 43 white.

Determine the expected ratio and the type of genetic interaction involved.

### 9:4:3 ratio = recessive epistasis

22