Genetics Chapter 9

duplication

chromosome _______ a mutation in which part of the chromosome has been doubled

inversion

chromosome _______ is when a chromosome segment is inverted 180 degrees. EX. ( ABCD BECOME CDBA)

deletion

chromosome ________ is the loss of a chromosome segment

allopolyploidy

chromosomes sets are form two or more species

reverse

____ duplication is when the duplicated sequence is inverted EX. "EF BECOMES FE"

robertsonian translocation 2

_____ had a role in evolution Apes and gorrilias have 46 chromosmes we have 48. Human chromosome number ___ was formed from this.

reciprocal

_____ translocation entails a 2-way exchange of segments between the chromosomes

tandem

_______ duplication is when the duplicated region is immediately adjacent to the original segment

polyploidy

_______ is common in plants

displaced

________ duplicated is when the duplicated sequence is located some distance from the original segment

paracentric pericentric

___________ inversions do not include the centromere, while _______ inversions include the centromere

translocation

a ___________ entails the movement of genetic material b/w NON-HOMOLOGOUS chromosomes or within the same chromosome

increases

a female risk of bear a trisomy 21 child _____ exponentially as she ages

autopolyploidy

all chromosomes sets are from a single species

robertsonian translocation nondisjuction

anueploidy is caused by the loss of a chromosome in mitosis/meiosis, or by _________ during which the small chromosome is lost, and _________ during which chromosomes/chromatids fail to separate during mitosis/meiosis

fragile sites 100,000 one

areas on the chromosome prone to breakage , usually ______________ bp long, and contain at least ___ gene

tetrasomy 2n + 2

gain of a homologous pair

trisomy 2n+1

gain of a single chromosome

down syndrome

having 3 full copies of chromosome 21

familial down syndrome

having 46 chromosomes and an extra copy of part of chromosome 21 caused by robertsonian translocation. 4% of trisomy 21 cases.

monosomy 2n-1

loss of a single chromosome

nullisomy 2n-2

lossof both members of a homologous pair , and equation

position effect

many genes are regulated in a position-dependent manner; if their positions are altered by an inversion, they may be expressed at inappropriate times or in inappropriate tissues, an outcome referred to as a ________

spontaneous abortions

most aneuploidly in humans result in __________________________

mosaicism

nondisjuction can causes patches of normal; cells and patches of abnormal cells

inversion loop

pairing of chromosomes in heterozygotes for an inversion requires an ___________

x-chromosome inactivation

sex-chromosome aneuploids are tolerated because of ____________ and because y chromosomes have so littler information on them

haploidinsufficient gene

some genes require two copies for normal function, when a single copy of a gene is not sufficient to produce a wild-type phenotype it is said to be a _____________

karyotype

the complete set of chromosomes possessed by an organism is called its ______

pericentric

there is a _________ inversion in human and chimpanzees chromosome 4

nullisomy, monosomy, trisomy, tetrasomy

4 types of common anueploid conditions

pseudodominance deletion

The expression of a normally recessive mutation is referred to as _________, and it is an indication that one of the homologous chromosomes has a ______

unequal crossing over

how do duplication arise?

polyploidly

in _____, one or more complete sets of chromosomes are added

pericentric

in _______ inversions the recombinant chromosomes either have too many copies of some some egnes and no copies of others.

aneuploidy

in _______ the number of chromosomes is altered: one or more individual chromosomes are added or deleted

nonreciprocal

in _______ translocation, genetic material moves from one chromosome to another without any reciprocal change

paracentric

in _________ inversions; during meiosiswhen crossing over occurs in the inversion sequence a dicentric chromatid (has 2 chromosomes) and a acentric chromatid (has 0 centromeres) is formed. 2 gametes are good but the other 2 are both missing genes and wont be viable.

chromosome rearrangements

in ______________ the structure of the chromosomes is altered for example a piece of chromosomes might be duplicated, deleted, or inverted.

robertsonian

in a _________ translocation, the 2 long arms of an acrocentric chromosome come together while to 2 end bits come together. the the smaller chromosome often fails to segregate

duplication, deletions, inversions, translocation

what are the four basic type of chromosomes rearrangements

uniparental disomy

when both chromosomes are inherited from the same parent. probably due to trisomy with one of the chromosomes being lost. gives rises to autosomal recessive disorder even if only one parent is a carrier.

loop out

when chromosomes who have been affected by duplication pair up during meiosis the duplicated sequence must ________ in order for the homologous sequences of the chromosomes to align

loop

when one chromosome has a deletion the normal segments of the chromosome must ___ inorder for homologous sections to pair