karyotyping

Question 2

• Humans have a diploid number (2n) of ___
  chromosome

Answer 2

46

Question 3

The gametes contain only _ copy of each pair of
chromosome

Answer 3

one

Question 4

Each chromosome contains a region
called the ___, which
divides the chromosome into two
arms

Answer 4

centromere

Question 5

Chromosomes can be classified
according to the location of the
__

Answer 5

centromere

Question 6

metacentric
submetacentric
acrocentric - near the end
telocentric - at the end

Answer 6

metacentric
submetacentric
acrocentric - near the end
telocentric - at the end

Question 7

Human males and females have one pair of sex
chromosomes that are not completely
__

Answer 7

homologous

Question 8

Females have two homologous ___chromosomes

Answer 8

X

Question 9

Males have a nonhomologous pair, consisting of __chromosome

Answer 9

one X and one Y

Question 10

Chromosomes other than sex chromosomes are
called __

Answer 10

autosomes

Question 11

The autosomes are numbered 1-22
in __ order of length

Answer 11

descending

Question 12

The sex chromosomes are labelled
as __

Answer 12

X and Y

Question 13

On the basis of size and centromere
placement, human autosomal
chromosomes are divided into
seven groups

Answer 13

A (1-3), B (4-5), C, (6-12), D (13-15), E (16-18), F (19-20), and G (21-22)

Question 14

Karyotype

The chromosomes are usually
studied and photographed while
they are in __ of mitosis

Answer 14

metaphase

Question 15

They are arranged in pairs according
to size and centromere location to
form a __

Answer 15

karyotype

Question 16

Chromosome ___ are
used to identify specific regions on each
chromosome

Answer 16

banding patterns

Question 17

The short arm of each chromosome is
designated the _, and the long arm
the ___

Answer 17

p arm; q arm

Question 18

Each arm is subdivided into numbered
__ beginning at the centromere

Answer 18

regions

Question 19

Within each region, the bands are
identified by ___

Answer 19

number

Question 20

This address consists of the
____

Answer 20

chromosome number (1), the
arm (q), the region (2), and
the band (4)

Question 21

Karyotypes are constructed by using ___ from a number of sources

Answer 21

cells

Question 22

One of the most common methods of preparing cells begins with a ___ sample

Answer 22

blood

Question 23

Few drops of blood are added to a flask containing a ___ growth medium

Answer 23

nutrient

Question 24

A mitosis-inducing chemical such as ___ is added to the flask

Answer 24

phytohemagglutinin

Question 25

the cells are grown for __ days at body temperature in an incubator

Answer 25

2 or 3

Question 26

A drug such as ___ is added to stop dividing cells at metaphase

Answer 26

Colcemid

Question 27

Over a period of about 2 hours of treatment, all cells entering mitosis are arrested in ___

Answer 27

metaphase

Question 28

The blood cells are concentrated by ___

Answer 28

centrifugation

Question 29

A ___ solution is added to break open and destroy the RBCs and swell the lymphocytes

Answer 29

salt

Question 30

Fixation in a mixture of ___

Answer 30

methanol and acetic acid

Question 31

The swollen __ are dropped onto a microscope slide

Answer 31

lymphocytes

Question 32

* The fragile cells will break open, spreading )___ chromosomes onto the slide

Answer 32

metaphase

Question 33

The preparation is partially digested with __

Answer 33

trypsin

Question 34

After staining, the preparation is examined with a microscope and a cluster of metaphase chromosome is located true or falsw

Answer 34

true

Question 35

___ are prepared from the cluster of metaphase chromosomes

Answer 35

Computer generated karyotypes

Question 36

___ are used to produce a pattern of bands that is specific to each chromosome

Answer 36

Stains and dyes

Question 37

The most common method is ___, in which chromosomes are first treated with an enzyme (trypsin) that partially digest chromosomal proteins and then are stained with Giemsa stain

Answer 37

G-banding

Question 38

The resulting pattern of bands is used to identify individual chromosomes in cytogenetic analysis true or false

Answer 38

true

Question 39

Metaphase chromosomes have a total of about __ band

Answer 39

550

Question 40

treat metaphase spreads with the chemical quinacrine mustard. Observe fluorescent banding pattern with a special ultraviolet light microscope

Answer 40

q banding

Question 41

heat metaphase spreads at high temperature to achieve partial denaturation of DNA. Stain with Giemsa stain. Observe with light microscope

Answer 41

R banding

Question 42

chemically treat metaphase spreads to extract DNA from the arms but not the centromeric regions of chromosomes. Stain with Giemsa stain ad obserce with light microscope

Answer 42

c banding

Question 43

pattern is the reverse of the G bandig

Answer 43

R banding

Question 44

darkly stained c band centromeric region of the chromosome corresponds to region of constitutive heterochromatin

Answer 44

c banding

Question 45

A karyotype provides several kinds of information

Answer 45

* 1. The number of chromosomes * 2. Sex chromosome content * 3. Presence or absence of individual chromosomes * 4. Nature and extent of any large structural abnormality

Question 46

Almost any cell with a nucleus can be used to make a __

Answer 46

karyotype

Question 47

In adults, ___ are used routinely

Answer 47

lymphocytes, skin cells (fibroblasts), and cells from biopsies or surgically removed tumor cells

Question 48

Chromosomal abnormalities can be detected before birth by using ___ sampling to collect cells from embryos and fetuses

Answer 48

amniocentesis and chorionic villus

Question 49

A technique used routinely to collect fetal cells for analysis

Answer 49

Amniocentesis

Question 50

The fetus and placenta are located by ultrasound, and a needle is inserted through the abdominal and uterine walls (avoiding the placenta and fetus) into the amniotic sac surrounding the fetus

Answer 50

Amniocentesis

Question 51

Amniocentesis Approximately___ of fluid is withdrawn by syringe

Answer 51

10-30

Question 52

The fluid is mostly fetal urine containing cells shed from the skin, respiratory tract, and urinary tract of the fetus true or false

Answer 52

true

Question 53

Amniocentesis Cells are isolated from the fluid by ___

Answer 53

centrifugation

Question 54

Karyotype analysis makes it possible to diagnose the sex of the fetus t or f

Answer 54

t

Question 55

Amniocentesis is not performed until the ___ week of pregnancy

Answer 55

16th

Question 56

Before the 16th week, there is very little amniotic fluid and contamination of the sample with maternal cells is often a problem t or f

Answer 56

t

Question 57

Amniotic cells can be analyzed to detect ____

Answer 57

biochemical disorders or chromosome abnormalities

Question 58

Advance maternal age – risk of having children with chromosome abnormalities increases dramatically after age _

Answer 58

35

Question 59

The procedure is normally used under certain condition

Answer 59

1. Advance maternal age – risk of having children with chromosome abnormalities increases dramatically after age 35 * 2. Previous child with a chromosomal aberration * 3. A parent with a chromosome rearrangement * 4. X-

Question 60

CVS retrieves fetal tissue from the __

Answer 60

placenta

Question 61

This has several advantages over amniocentesis

Answer 61

Chorionic Villus Sampling

Question 62

It can be performed earlier in pregnancy (8 to 10 weeks)

Answer 62

orionic Villus Sampling

Question 63

Because placental cells are already dividing and do not have to be induced to begin mitosis, karyotypes are available within a few hours or a few days t or f

Answer 63

t

Question 64

his procedure, a flexible catheter is inserted through the vagina or abdomen into the uterus, guided by ultrasound images

Answer 64

Chorionic Villus Sampling

Question 65

Some chorionic villi are removed by ___

Answer 65

suction

Question 66

__ is used less often than amniocentesis

Answer 66

CVS

Question 67

It offers early diagnosis of genetic diseases, and if termination of pregnancy ___9 to 12 weeks than at 16 week

Answer 67

is elected, maternal risks are lower at