Chapter 22

Question 1

Which two stages of the cell cycle are best for producing a karyotype?

Answer 1

Metaphase and prometaphase

Question 2

What is the name of the stain used for producing the banding patterns found on chromosomes?

Answer 2

Giemsa stain

Question 3

What name is given to the bands observed on chromosomes?

Answer 3

G-bands

Question 4

In addition to their length, what other chromosomal feature is easily observed in a karyotype?

Answer 4

The position of the centromere

Question 5

What term describes a chromosome whose centromere is close to the middle?

Answer 5

Metacentric

Question 6

What term describes the two arms of a chromosome?

Answer 6

p-arm and q-arm

Question 7

Which chromosome arm is shorter?

Answer 7

p-arm

Question 8

Do chromosome band numbers increase or decrease closer to the telomere?

Answer 8

Increase

Question 9

Is a gene located at 6q16.1 closer to the centromere or telomere than 6q21.2?

Answer 9

Centromere

Question 10

What is the general term for a “jumping gene” that can copy and insert itself into multiple locations in the genome?

Answer 10

Transposon

Question 11

What type of deletion involves the removal of an internal section of DNA?

Answer 11

Interstitial deletion

Question 12

Is Cri-du-chat syndrome the result of a deletion of a piece of a chromosome or the entire chromosome?

Answer 12

A piece of a chromosome

Question 13

What is the fancy term for a gene paralog picking up a new function?

Answer 13

Neofunctionalization

Question 14

Genes that share a common ancestral gene are considered what?

Answer 14

Homologs

Question 15

In the human genome, similar genes that encode different versions of a protein are called what?

Answer 15

Paralogs

Question 16

What are proteins called that perform similar but not identical reactions, or may be expressed in different conditions?

Answer 16

Isoforms

Question 17

Inversions that span the centromere are called what?

Answer 17

Pericentric inversions

Question 18

What structure must form during synapsis to align homologous regions of chromosomes with inversions?

Answer 18

Inversion loop

Question 19

Chromosomal mutations like inversions and translocations may contribute to what biological phenomenon?

Answer 19

Emergence of new species

Question 20

Are polyploid cells considered euploid or aneuploid?

Answer 20

Euploid

Question 21

What is the chromosome condition of cells with 1n, 2n, and 3n sets of chromosomes?

Answer 21

Haploid, diploid, triploid

Question 22

A cell missing one chromosome is said to have what type of aneuploidy?

Answer 22

Monosomy

Question 23

What is the most common autosomal aneuploidy in humans?

Answer 23

Trisomy 21

Question 24

What is the name of the technique used to screen for aneuploidies in cells?

Answer 24

Fluorescence In Situ Hybridization (FISH)

Question 25

What prenatal diagnostic procedure allows doctors to check chromosome numbers?

Answer 25

Amniocentesis

Question 26

What is the process called when the spindle improperly segregates chromosomes?

Answer 26

Nondisjunction

Question 27

What sex chromosome condition results in Turner Syndrome?

Answer 27

XO (Monosomy X)

Question 28

What condition is characterized by an individual with an extra X chromosome (XXY)?

Answer 28

Klinefelter Syndrome

Question 29

What happens to extra X chromosomes in cells, making their aneuploidies less harmful?

Answer 29

They are inactivated (form Barr bodies).

Question 30

What happens to a gamete with an extra chromosome during nondisjunction?

Answer 30

It also creates a gamete missing that chromosome.

Question 31

Does the incidence of aneuploidies at birth increase with maternal age?

Answer 31

Yes

Question 32

Why are sex chromosome aneuploidies less harmful than autosomal aneuploidies?

Answer 32

Many sex chromosomes can be inactivated in each cell.

Question 33

What is the karyotype for Turner Syndrome?

Answer 33

XO (Monosomy X)

Question 34

What are the developmental effects of Turner Syndrome?

Answer 34

Development of female sex characteristics

Question 35

Does Triple-X Syndrome (XXX) typically lead to noticeable differences in individuals?

Answer 35

No

Question 36

Do individuals with Klinefelter Syndrome (XXY) have Barr bodies in their cells?

Answer 36

Yes

Question 37

Which chromosome is inactivated in individuals with Klinefelter Syndrome?

Answer 37

X chromosome

Question 38

When do many individuals with Klinefelter Syndrome discover their condition?

Answer 38

When seeking treatment for infertility