Where mutation in a single gene can cause multiple, seemingly unrelated phenotypes

Where mutation in a single gene only causes a change in a single trait

Aneuploidy | Quiz

Question 1

Question

What is it called when homologous chromosomes fail to separate properly?

Image:

Meiosis_1_Disjunction (image/png)

Answer

Meiosis 1 disjunction
Meiosis 2 disjunction
Precocious sister chromatid separation

Question 2

Question

The following shows the sister chromatids failing to separate during Meiosis 2- aka Precocious sister chromatid separation

Image:

Meiosis_2_Disjunction (image/png)

Answer

True
False

Question 3

Question

Of the four gametes, 2 of one pair are normal, and of the other pair one is disomic and the other is nullosomic- what has gone wrong?

Answer

Meiosis II Non-disjunction
Meiosis I disjunction
Precocious sister chromatid separation

Question 4

Question

What is different about Meiosis II non-disjunction and Precocious sister chromatid separation?

Answer

In MII, the nullosomic and disomic gametes occur from the same cell In PSCS, the nullosomic and disomic gametes occur from different cells
In PSCS, the nullosomic and disomic gametes occur from the same cell In MII, the nullosomic and disomic gametes occur from different cells

Question 5

Question

Aneuploidy- an abnormality of chromosome number where the number of chromosomes present is not a multiple of the haploid number

Answer

True
False

Question 6

Question

Nullosomy- where one of the chromosomes is lost (2n-1)

Answer

True
False

Question 7

Question

Monosomy is universally lethal to humans embryo's

Answer

True
False

Question 8

Question

Which of the following is fatal in animals but not always in plants

Answer

Nullosomy
Trisomy
Monosomy

Question 9

Question

Trisomy's of some chromosomes are survivable in humans

Answer

True
False

Question 10

Question

Down's Syndrome is caused by trisomy of which chromosomes?

Answer

Question 11

Question

Down's Syndrom is present in 1/750 babies

Answer

True
False

Question 12

Question

Which of the following are potentially symptoms of Down's Syndrome?

Answer

Abnormal fingerprints
Congenital heart disease
Gigantism
Intellectual disability
Webbed fingers

Question 13

Question

Trisomy 18 is Ptau's syndrome and is found in 1/6000 births

Answer

True
False

Question 14

Question

Which of the following are potentially symptoms of Edwards syndrome?

Answer

Rockerbottom/clubbed feet
Muscle rigidity
Intellectual disability

Question 15

Question

Ptau's Syndrome is the most common, present in 1/200 births

Answer

True
False

Question 16

Question

List the potential symptoms of Ptau's syndrome

Answer

Clubbed/rocker bottom feet
Post axial polydactyly
Cleft lip/palate

Question 17

Question

In fetus' with Ptau's Syndrome, there are 100x more spontaneous abortions/lost pregnancies that stillbirths

Answer

True
False

Question 18

Question

When distinguishing between types of mis-segregation, what is required for direct assessment of genetic markers (ideally)?

Answer

Allele- specific PCR.
Genetic information from siblings
Genetic offspring from a parent
Genetic offspring from both parents
Genetic offspring from grandparents

Question 19

Question

90% of aneuploidy's are caused by the sperm, not the egg

Answer

True
False

Question 20

Question

Define Pleiotropy

Answer

Where mutation in a single gene only causes a change in a single trait
Where mutation in a single gene can cause multiple, seemingly unrelated phenotypes

Question 21

Question

Aneuploidy effects entire chromosomes, and so its effects are always Pleiotropic

Answer

True
False

Question 22

Question

A phenotype associated with a pleiotrophic gene may show greater expressivity than another phenotype associated with the same gene

Answer

True
False

Question 23

Question

Match the following Trisomies with the problematic chiasmata in the Maternal Meiosis diagram

Image:

Trisomy_recombinations (image/png)

Answer

Top- 16 (proximal) Mid- 18 (achiasmate) Bot- 21 (achiasmate, proximal, distal)
Top- 21 (proximal) Mid- 18 (achiasmate) Bot- 16 (achiasmate, proximal, distal)
Top- 18 (proximal) Mid- 16 (achiasmate) Bot- 21 (achiasmate, proximal, distal)

Question 24

Question

Without crossover, only 40% of homologous chromosomes align correctly

Answer

True
False

Question 25

Question

Define the Chiasma hypothesis

Answer

Chiasma make the cell more vulnerable to aneuploidy
Without crossover, cells become more vulnerable to aneuploidy

Question 26

Question

Silkworm females and male sloths pair each side of the synaptonemal complex with no crossing over

Answer

True
False

Question 27

Question

Once produced, how are oocytes stored in the uterus and for how long?

Answer

As bivalents
As a synaptonemal complex
3-5 weeks
3-5 years
10-50 years

Question 28

Question

The way oocytes are stored is known as Dictyate Arrest

Answer

True
False

Question 29

Question

What makes the continued arrestment of oocytes in bivalent form difficult?

Answer

Cohesin is lost as cells age
DNA begins to degenerage if held in bivalent form too long
Bivalents held together too long will bind too tight to be unwound

Question 30

Question

List the three things that can happen in an aging oocyte

Answer

The bivalent cannot be broken
The DNA begins to degrade
There is precocious loss of centromere cohesin in Meiosis I
There is Precocious Separation of sister chromatids
A univalent is formed

Question 31

Question

During dictyate arrest, achiasmate segregation factors can deplete

Answer

True
False

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Aneuploidy

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Question 26

Question 27

Question 28

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Question 30

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	Created by gina_evans0312 over 10 years ago

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