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