Chapter 8: Abberations

Question 1

Chromosomes can be identified by

Answer 1

1. location of centromere
2. size
3. banding patterns

Question 2

Metacentric

Answer 2

centromere near the middle of the chromosome

Question 3

Subcentric

Answer 3

centromere slightly off-center

Question 4

Acrocentric

Answer 4

centromere significantly off-center but not at either end

Question 5

Telocentric

Answer 5

centromere is at one end

Question 6

Chromosomes are numbered according to

Answer 6

size (large to small)

Question 7

Banding patterns are used if

Answer 7

multiple chromosomes have a similar size and centromere location.

Question 8

Stains are applied to see what?

Answer 8

banding patterns

Question 9

Deletion

Answer 9

the condition in which a segment of chromosomal materials is missing

Question 10

Duplication

Answer 10

repetition of a segment of DNA more than once within a genome

Question 11

Inversion

Answer 11

a change in the direction of genetic material along a chromosome in which a segment is flipped so it runs in the reverse direction

Question 12

Translocation

Answer 12

the phenomenon in which one segment of a chromosome breaks off and becomes attached to a different chromosome or a different part of the same chromosome

Question 13

_______ alters the total amount of genetic material in the chromosome

Answer 13

deletion

Question 14

_______ tends to be terminal

Answer 14

deletion

Question 15

_______ occurs when a chromosome breaks in 1 or more places and a fragment is lost

Answer 15

deletion

Question 16

terminal deletion

Answer 16

at the end of a chromosome

Question 17

interstitial deletion

Answer 17

internal segment lost

Question 18

deletion effects depend on if __________ or ____________ genes were lost

Answer 18

essential, nonessential

Question 19

_______ alter the total amount of genetic material in the chromosome

Answer 19

duplications

Question 20

extra material is gained in

Answer 20

duplications

Question 21

may be caused by abnormal crossing over i.e. misaligned homologous chromosomes

Answer 21

duplications

Question 22

Pericentric inversion

Answer 22

the centromere is located within the inverted region of the chromosome

Question 23

paracentric inversion

Answer 23

the centromere is found outside the inverted region

Question 24

inversions cause it to run

Answer 24

in the opposite direction

Question 25

does not affect the amount of genetic material

Answer 25

inversions

Question 26

piece of a chromosome is attached to another, not its sister chromatid.

Answer 26

translocations

Question 27

Balanced translocation

Answer 27

does not alter the total amount of genetic material

Question 28

unbalanced translocation

Answer 28

results in a cell having too much or too little genetic material compared to a normal cell

Question 29

Robertsonian translocation

Answer 29

*most common type in humans * REARRANGEMENT OF GENETIC MATERIAL THAT ARISES FROM BREAKS NEAR THE CENTROMERES OF TWO NONHOMOLOGOUS ACROCENTRIC CHROMOSOMES

Question 30

two types of changes in chromosome number

Answer 30

1. variation in the number of SETS of chromosomes 2. variation in the number of chromosomes WITHIN a set

Question 31

Euploid

Answer 31

an organism in which the chromosome # is an exact multiple of a chromosome set. Ex. Dipliod (2n), Triploid (3n), Tetraploid (4n)

Question 32

Aneupliod

Answer 32

an abnormal variation in chromosome # such that the total # of chromosomes is not an exact multiple of a set or number. Ex. 2n+1, 3n-1: an aberration of euploidy

Question 33

Endopolyploidy

Answer 33

occurrence of cells that are polyploid in an otherwise diploid animal

Question 34

Euploidy variations

Answer 34

variation in the # of sets of chromosomes

Question 35

Aneuploidy variations

Answer 35

variation in the # of chromosomes within a set

Question 36

causes an imbalance of gene expression

Answer 36

Aneuploidy variations

Question 37

often detrimental to phenotype

Answer 37

Aneuploidy variations

Question 38

Meiotic Nondisjunction

Answer 38

chromosomes do not segregate equally during meiosis

Question 39

Mitotic Nondisjunction

Answer 39

chromosomes do not segregate equally during mitosis

Question 40

* will result in gametes with the incorrect amount of chromosomes * effects differ based on if it occurs in meiosis 1 or 2

Answer 40

Meiotic Nondisjunction

Question 41

*Occurs in somatic cells *Abnormality in chromosome # is occurring after fertilization

Answer 41

Mitotic Nondisjunction

Question 42

Two possibilities of Mitotic Nondisjunction

Answer 42

1. sister chromatids separate improperly 2. sister chromatid improperly attached to mitotic spindle is degraded

Question 43

Mosaic

Answer 43

cells of part of an organism differ genetically from the rest of the organism.