Chromosome and Banding

Question 1

consists primarily of DNA and proteins with a small amount of RNA

Answer 1

Chromosome

Question 2

considered a chromosomal aberration if it is large enough to be seen with a light microscope using stains and/or fluorescent probes to highlight missing, extra, or moved genetic material

Answer 2

Mutations

Question 3

dark colored, consists mostly of highly repetitive DNA sequences

Answer 3

Heterochromatin

Question 4

dark colored, consists mostly of highly repetitive DNA sequences

Answer 4

Heterochromatin

Question 5

light colored, has many protein-encoding sequences

Answer 5

Euchromatin

Question 6

repetitive DNA sequences found at the end of the chromosome

Answer 6

telomeres

Question 7

largest constriction of a chromosome, where spindle fibers attach when the cell divides

Answer 7

Centromere

Question 8

contacts the spindle fibers, enabling the cell to divide

Answer 8

Kinetochore

Question 9

chromosome parts that lie between protein-rich areas and the telomeres

Answer 9

Subtelomeres

Question 10

standard chromosome chart, it displays chromosomes in pairs by size and by physical landmarks that appear during mitotic metaphase, when DNA coils tightly, enabling it to be visualized

Answer 10

Karyotype

Question 11

a karyotype with one extra chromosome

Answer 11

Trisomy

Question 12

the centromere divides the chromosome into two arms of approximately equal length

Answer 12

Metacentric

Question 13

the centromere establishes one long arm and one short arm

Answer 13

Submetacentric

Question 14

It pinches off only a small amount of material toward one end

Answer 14

Acrocentric

Question 15

the centromere is near one end, although telomere DNA, sequences are at the tip

Answer 15

Telocentric

Question 16

blob-like ends, found in five human
chromosomes (13, 14, 15, 21,
and 22), that extend from a
thinner, stalklike bridge from
the rest of the chromosome

Answer 16

Satellites

Question 17

performed between 14 and 16 weeks of gestation, when the fetus is not yet very large but amniotic fluid is plentiful

Answer 17

Amniocentesis

Question 18

a procedure that is less accurate than amniocentesis and in about 1 in 1,000 to 3,000 procedures, it halts development of the feet and/or hands and may be lethal

Answer 18

Chorionic villus sampling

Question 19

it has the ability to highlight individual genes. It can also “paint” entire karyotypes by probing each chromosome with several different fluorescent molecules

Answer 19

Fluorescence in situ hybridization (FISH)

Question 20

shows chromosome arms and numbered regions, called bands, and subbands

Answer 20

Ideogram

Question 20

shows chromosome arms and numbered regions, called bands, and subbands

Answer 20

Ideogram

Question 21

46, XY

Answer 21

Normal male

Question 22

46, XX

Answer 22

Normal female

Question 23

45, X

Answer 23

Turner syndrome (female)

Question 24

47, XXY

Answer 24

Klinefelter syndrome (male)

Question 25

46, XY, del (7q)

Answer 25

male missing part of the long arm of chromosome 7

Question 26

47, XX, + 21

Answer 26

female with trisomy 21 down syndrome

Question 27

46,XY,t(7;9)(p21.1;q34.1)

Answer 27

a male with a translocation between the short arm of chromosome 7 at band 21.1 and the long arm of chromosome 9 and band 34.1

Question 28

48, XXYY

Answer 28

male with an extra X and Y chromosome

Question 29

biochemicals whose levels in the blood are within a certain range in a pregnant woman carrying a fetus with the normal number of chromosomes, but lie outside that range in fetuses whose cells have an extra copy of a certain chromosome

Answer 29

Maternal serum markers

Question 30

is made in the yolk sac and leaves the fetal circulation and enters the maternal bloodstream at a certain rate

Answer 30

Alpha fetoprotein

Question 31

can detect certain fetal chromosomal abnormalities, like some of the trisomy conditions

Answer 31

Cell-free DNA testing

Question 32

cell with extra set of chromosomes

Answer 32

Polyploid

Question 33

cells missing a single chromosome or having an extra chromosome

Answer 33

Aneuploid

Question 34

a normal chromosome number

Answer 34

Euploid

Question 35

cells with one missing chromosome

Answer 35

Monosomy

Question 36

The most frequently seen extra autosomes in newborns are chromosomes 21, 18, and 13, because these chromosomes carry many fewer protein- encoding genes than other autosomes, compared to their total amount of DNA.

Answer 36

Autosomal aneuploids

Question 37

A person with Down syndrome is usually short and has straight, sparse hair and a tongue protruding through thick lips. The hands have an atypical pattern of creases, the joints are loose, and poor reflexes and muscle tone give a “floppy” appearance.

Answer 37

Trisomy 21

Question 38

associated with edwards syndrome have great physical and intellectual disabilities, with developmental skill stalled at the 6-month level. Edwards Syndrome

Answer 38

Trisomy 18

Question 39

associated with patau syndrome. Major abnormalities affect the heart, kidneys, brain, face, and limbs. The nose is often malformed, and cleft lip and/or palate is present in a small head. There may be extra fingers and toes.

Answer 39

Trisomy 13

Question 40

is more frequent among spontaneously aborted fetuses than among newborns—99 percent of XO fetuses are not born.

Answer 40

XO Syndrome or Turner Syndrome

Question 41

The lack of symptoms reflects the protective effect of X inactivation—all but one of the X chromosomes is inactivated.

Answer 41

Triplo X

Question 42

diagnosed with Klinefelter syndrome.

Answer 42

XXYY Syndrome

Question 43

arises from nondisjunction in the male, producing a sperm with two Y chromosomes that fertilizes a normal oocyte.

Answer 43

XYY Syndrome

Question 44

Inactivated following fertilization and embryonic development. Proposed by Mary Lyon (Lyon Hypothesis)

Answer 44

X Inactivation

Question 45

represents the X chromosome that is inactive

Answer 45

Barr Bodies

Question 46

A chromosome can be structurally atypical in several ways. It may have too much or too little genetic material, or a stretch of DNA that is inverted or moved and inserted into a different type of chromosome.

Answer 46

Atypical chromosome structure

Question 47

used to detect very small CNVs, which are also termed microdeletions and microduplications.

Answer 47

Comparative genomic hybridization

Question 48

the short arm of two different acrocentric chromosomes break, leaving sticky ends on the two long arms that join, forming a single, large chromosome with two long arms.

Answer 48

Robertsonian translocation

Question 49

person with large, translocated chromosome.

Answer 49

Translocation carrier

Question 50

is inherited or de novo, just as they can from a Robertsonian translocation.

Answer 50

Reciprocal translocation

Question 51

a rare type of translocation, in which part of one chromosome inserts into a nonhomologous chromosome.

Answer 51

Insertional translocation

Question 51

a rare type of translocation, in which part of one chromosome inserts into a nonhomologous chromosome.

Answer 51

Insertional translocation

Question 52

the inverted section does not include the centromere.

Answer 52

Paracentric inversion

Question 53

the inverted section does not include the centromere.

Answer 53

Paracentric inversion

Question 54

includes the centromere within the loop. A crossover in the inversion loop produces two chromatids that have duplications and deletions, but one centromere each, plus one normal and one inversion chromatid.

Answer 54

Paracentric inversion

Question 55

result of another meiotic error that leads to unbalanced genetic material.

Answer 55

Isochromosome

Question 56

may arise when telomeres are lost, leaving sticky ends that adhere.

Answer 56

Ring chromosome

Question 57

unrestrained proliferation and migration of cells.

Answer 57

Cancer

Question 58

Genes associated with cancer

Answer 58

Oncogene or protooncogenes

Question 59

a genetic condition that affects several parts of your child's body, including their face, heart, brain and height

Answer 59

wolf hirschhorn syndrome