Chromosomes: Gametes and preimplantation human embryos

Question 1

Haploid gametes produce ___________ offspring

Answer 1

DIploid

Question 2

What are some examples of aneuploidy?

Answer 2

Trisomy and monosomy

Question 3

Haploidy is _________ set(s) of chromosomes

Answer 3

One

Question 4

Polyploidy is more than _________ chromosomes

Answer 4

2N

Question 5

Chromosomes rearrangements include translocations, deletions, ___________ and duplications

Answer 5

Inversions

Question 6

True or false: The risk of having a child with chromosomal aberrations is smaller when a woman is older vs when a woman is younger

Answer 6

False, it is the opposite way around

Question 7

True or false: Older men are 3 times more at risk of having children with Trisomy 21 than younger men

Answer 7

True

Question 8

When can chromosome abnormality occur in gametogenesis?

Answer 8

Meiosis I and II, oogenesis, spermatogenesis

Question 9

When can chromosome abnormality occur in fertilization?

Answer 9

Dispermic fertilization, digynic fertilization after ISCI, parthogenetic activation

Question 10

When can chromosome abnormality occur in embryogenesis?

Answer 10

Mitotic error

Question 11

What is the phenomenon of abnormal chromosome segregation?

Answer 11

Non-disjunction

Question 12

When does non-disjunction occur during meiosis I in eggs?

Answer 12

Anaphase I

Question 13

What is the result of non-disjunction during meiosis I in eggs?

Answer 13

Disomic and nullisomic gametes

Question 14

Normal chromosome segregation in meiosis I results in ___________ gamete

Answer 14

2N

Question 15

Non-disjunction in meiosis I leads to __________ or ____________

Answer 15

Trisomy; monosomy

Question 16

Pre-division of chromatids in meiosis I leads to _____________

Answer 16

PSSC (premature separation of sister chromatids)

Question 17

True or false: Pre-division of both univalents leads to a balanced MII oocyte

Answer 17

True

Question 18

Which aspects of abnormal chromosome segregation are present in meiosis I but not in meiosis II?

Answer 18

Recombination failure, premature homologue separation

Question 19

Karyotyping in eggs indicated an incidence rate of aneuploidy equal to ________ %

Answer 19

10-35

Question 20

Which method for detecting aneuploidy in eggs had the highest incidence?

Answer 20

CGH

Question 21

PSSC in sperm leads to ________, normal and ____________ spermatozoa

Answer 21

Disomic; nullisomic

Question 22

True non-disjunction in sperm leads to ___________ and _______________ spermatozoa

Answer 22

Disomic; nullisomic

Question 23

Which methods are used to observe aneuploidy in sperm?

Answer 23

FISH and karyotyping

Question 24

What are other methods to observe human aneuploidy?

Answer 24

SKY and NGS

Question 25

FISH technology uses a probe __________ labelled with fluorescent dye

Answer 25

DNA

Question 26

Which four methods are used for detection of chromosomal copy number variation?

Answer 26

FISH, CGH, aCGH and SNP

Question 27

Abnormal fertilized embryo shows _______ pronuclei instead of __________

Answer 27

Three; two

Question 28

Digynic triploidy is characteristic of _____________ of a second polar body

Answer 28

Suppression

Question 29

What is a mosaic embryo?

Answer 29

A mix of normal and abnormal cells

Question 30

Mitotic error occurs in which stage of mosaic embryo formation?

Answer 30

2-cell stage

Question 31

Mosaicism is the presence of one or more genetically distinct cell lines within an ___________

Answer 31

Embryo

Question 32

Mosaicism is generated from a post ___________ error in an originally ___________ zygote

Answer 32

Zygotic; diploid

Question 33

What is trisomy zygote rescue?

Answer 33

Post zygotic error in an originally aneuploid zygote that leads to loss of one chromosome

Question 34

Uniparental disomy results in an embryo carrying _________ parent's gamete

Answer 34

One

Question 35

What percent of FISH results showed mosaic cells?

Answer 35

47%

Question 36

What are the two types of mosaic cells in blastocyst?

Answer 36

dp (polyploid) and da (aneuploid)

Question 37

A good quality blastocyst has a ______________ percent of polyploid cells than a bad quality blastocyst

Answer 37

Lower

Question 38

Which mechanisms are behind gain and loss error?

Answer 38

Non-disjunction, anaphase lag, chromosome demolition, chromosome replication

Question 39

Abnormal cells are allocated to the ______________

Answer 39

Trophectoderm

Question 40

Meiotic mosaicism often have adverse effect on the conceptus such as ____________ zygote rescue due to the presence of ___________ in the embryo/fetus

Answer 40

Trisomy; UPD

Question 41

In the case of trisomy 16, the fetus _______

Answer 41

Dies

Question 42

What is the most common trisomy after trisomy 16?

Answer 42

Trisomy 21 and 22

Question 43

Which trisomies are seen in live-born apart from sex chromosome abnormalities?

Answer 43

Trisomy 21, trisomy 13, trisomy 18

Question 44

Edward syndrome (Trisomy 18) is characterized by a _________ sternum, overlapping fingers with clenched __________ and _____________

Answer 44

Short; fists; clubfoot

Question 45

Patau syndrome (Trisomy 13) is characterized by defects of the __________, cleft _______ and palate and closely spaced ________

Answer 45

Brain; lip; eyes

Question 46

What are some sex chromosome abnormalities?

Answer 46

Turner syndrome (XO), Klinefelter syndrome (XXY), triple X, XYY

Question 47

What are some effects of Turner syndrome?

Answer 47

Short stature, broad chest, poor breast development

Question 48

Klinefelter syndrome affects one in 660 __________

Answer 48

Men

Question 49

What is the medical treatment for Klinefelter syndrome?

Answer 49

Testosterone replacement therapy

Question 50

What are some features of people with Klinefelter syndrome?

Answer 50

Tall stature, increased risk of learning disabilities, delayed development of speech and language skills and normal fertility

Question 51

What produces 47,XYY?

Answer 51

Parental non-disjunction at meiosis II resulting in an extra Y chromosome in sperm