Term
| The __________ reveals a constancy of chromosome organization within a species. |
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Definition
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Term
| Since several chromosomes are of the same approximate size, use is made of special staining techniques (__________ __________ __________ hybridization techniques, or __________ techniques such as Giemsa or G-banding) to identify two homologous chromosomes. |
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Definition
1) Fluorescent in situ
2) Banding |
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Term
| The standard nomenclature for chromosomes is __________ for the short arm and __________ for the long arm. |
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Definition
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Term
Depending upon the location of the centromere in a chromosome, it is called __________ (centromere in the middle, V-shaped at anaphase), __________ (centromere is off-center and J-shaped), and __________ or __________ (centromere near the end, L-shaped).
A chromosome without a centromere is called __________ and an abnormal chromosome with two centromeres is __________.
__________ and __________ chromosomes are unstable. |
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Definition
1) Metacentric
2) Submetacentric
3) Acrocentric
4) Telocentric
5) Acentric
6) Dicentric
7) Acentric
8) Dicentric |
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Term
In humans, there is dosage compensation of X-chromosomes and silencing of all but one __________-__________ in human females; this occurs on the __________ day after fertilization.
In each cell of the embryo, one of the two __________-__________ is randomly silences by compaction of the DNA (__________).
The inactive X-chromosome is visible in the female's cell nuclei and is called a __________ __________.
As a result, human females are __________. |
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Definition
1) X-chromosome
2) 16th
3) X-chromosomes
4) Heterochromitinzation
5) Barr body
6) Mosaic |
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Term
Due to the random silencing of the __________-__________, half the cells of a heterozygous female are still normal which explains why females do not show the deleterious effects of X-linked __________ mutations.
The condensation of the inactive X-chromosome begins at a site called __________-__________ __________ (XIC) |
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Definition
1) X-chromosome
2) Recessive
3) X-inactivation center |
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Term
Present day X and Y-chromosomes evolved from a common ancestral chromosome by loss of most of the __________-__________ genes.
Clearly, there is still some __________ between the X and Y-chromosome since they can pair in __________ and undergo __________ __________.
Actually, there are some gene in the X-chromosome that have __________ in the Y-chromosome (these do not follow sex-linked characteristics but behave like __________ genes).
During X-chromosome silencing, these common genes (shared with the __________-__________) are not silenced. |
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Definition
1) Y-chromosome
2) Homology
3) Meiosis
4) Crossing over
5) Homologs
6) Autosomal
7) Y-chromosome |
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Term
The common regions between X and Y-chromosomes are called __________ regions.
Crossing over during __________ formation occurs in these regions. |
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Definition
1) Psudoautosomal
2) Sperm |
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Term
The Y-chromosome in humans contains a master control region called __________ which is necessary for the formation of __________ characteristics.
Rare XX humans have a __________ of the SRY region to one of the X-chromosomes and rare XY human females have a __________ of the SRY region in the Y-chromosome.
The SRY gene codes for a transcription factor called the __________ __________ __________. |
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Definition
1) SRY (sex-determining region in Y)
2) Male
3) Translocation
4) Deletion
5) Testis determining factor |
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Term
Only a small part of the Y-chromosome pairs with the X-chromosome and all recombination during __________ is confined to this small area; the rest of the __________-__________ remains intact as a set of completely linked genes which are passed from fathers to sons.
Since recombination does not occur in this gene block, the only genetic changes are caused by __________ which are rare events. |
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Definition
1) Meiosis
2) Y-chromosome
3) Mutations |
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Term
Closely related races will have more similarity in their __________-__________ sequences and more changes will be seen in the DNA sequences of more distantly related races.
Analysis is done using __________ __________ __________ because they tend to mutate much more often due to slippage and mismatch correction leading to changes in the number of repeats at any one SSR site. |
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Definition
1) Y-chromosome
2) Simple sequence repeats (SSRs) |
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Term
Changes occur much more frequently in the __________ and as a result they are more informative about ancestry.
Y-chromosomes have many __________ sites and all are __________ of mutation. |
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Definition
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Term
| A specific set of alleles at two or more loci present in a particular chromosome is called a __________. |
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Definition
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Term
__________ DNA sequences have also been used for tracing ancestry of human races.
Like the __________-__________ sequences, mitochondrial DNA also does not undergo __________.
However, it is transmitted from __________ to their children (both sons and daughters; __________ do not contribute a significant amount of mitochondrial DNA since it has little cytoplasm compared to that contributed by the egg). Therefore, ancestry can be followed by analysis of mitochondrial DNA of __________. |
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Definition
1) Mitochondrial
2) Y-chromosome
3) Recombination
4) Mothers
5) Sperm
6) Females |
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Term
| __________ is when the cell division process occasionally goes wrong and chromosome partitioning is done incorrectly. |
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Definition
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Term
Individuals having an abnormality involving a whole chromosome set are called __________ or __________ (__________ = three chromosome sets; __________ = four chromosome sets) while those having an abnormal number of chromosomes (but not an extra complete set) are called __________.
An extra chromosome is called __________ while loss of one chromosome is called __________. |
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Definition
1) Euploids
2) Polyploids
3) Triploid
4) Tetraploid
5) Aneuploids
6) Trisomy
7) Monosomy |
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Term
| __________ of chromosome numbers are very poorly tolerated in humans. |
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Definition
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Term
Incidence of nondisjunction leading to __________ __________ goes up dramatically with the age of the mother.
It is fairly constant until age __________. |
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Definition
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Term
Due to the presence of three homologous chromosomes, trisomic have abnormal __________.
Usually, two chromosomes go to one pole and the third to the other pole.
In __________ __________ individuals, this happens randomly for each set of homologous chromosomes. |
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Definition
1) Meiosis
2) Double trisomic |
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Term
__________ for the sex chromosomes are viable and both XXX and XXY are seen.
XXX ones are __________ while XXY (__________ __________) have __________ characteristics. XO individuals survive occasionally and have __________ characteristics (__________ __________). They are usually sterile and have mental retardation. |
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Definition
1) Trisomics
2) Female
3) Klinefelter's syndrome
4) Male
5) Female
6) Turner's syndrome |
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Term
| Loss of part of a chromosome is called a __________; it leads to the uncovering of the gene on the normal chromosome and expression of deleterious __________ genes. |
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Definition
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Term
| The larger the deletion, the greater the probability that a harmful or lethal __________ gene will be uncovered. |
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Definition
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Term
There are many mechanisms for the generation of deletions.
One mechanism is due to recombination between two directly repeated sites in the same chromosome (__________ __________).
Normally, recombination occurs between __________ sites in the __________ homologous chromosomes; no deletions result from such a combination.
However, recombination between __________ sites on __________ chromosome can have devastating effects depending upon the orientation of the recombination sites.
If the sites are directly repeated, the whole sequence between the two sites along with one of the two repeats is __________.
If the two recombining sites are in __________ orientation, the entire sequence between the two sites is inverted. |
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Definition
1) Ectopic recombination
2) Two
3) Two
4) Two
5) One
6) Lost
7) Inverted |
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Term
| __________ involves the doubling of part of a chromosome; they may be __________ or __________. |
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Definition
1) Duplication
2) Tandem
3) Inverted |
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Term
| An example of a mutation due to a duplication is the __________-__________ phenotype in Drosphila. It is __________-__________ and partly dominant over the wild-type eye shape. It is caused by the duplication of the segment __________ in the __________-__________. |
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Definition
1) Bar-eye
2) X-linked
3) 16A
4) X-chromosome |
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Term
The genes for red and green pigments in the rod cells of human retinas are __________-__________ and near each other.
Because the two genes arose by the duplication of a single ancestral gene, they can pair sometimes and undergo unequal __________ __________.
This can result in gain and loss of color pigment genes or creation of defective fusion genes leading to __________-__________ color blindness. |
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Definition
1) X-linked
2) Crossing over
3) X-linked |
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Term
Part of a chromosome is inverted; if the centromere is not included in the inversion, then it is called a __________ __________. If the centromere is included then it is a __________ __________.
Meiotic consequences of an inversion depend upon whether it is homo or heterozygous; __________ inversions have normal meiosis (although the gene order has been rearranged).
Problems tend to occur if inversion is __________. |
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Definition
1) Paracentric inversion
2) Pericentric inversion
3) Homozygous
4) Heterozygous |
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Term
In heterozyous inversion, paring of homologs creates an __________ __________ which greatly reduces __________ or totally suppresses it in the inverted region.
Non-recombinant gametes have a full set of genes and survive; however one of the two parental gametes is __________ and the other __________. |
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Definition
1) Inversion loop
2) Recombination
3) Normal
4) Inverted |
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Term
__________ __________ and __________ __________ are created due to recombination within the inversion loop of a paracentric inversion.
The resulting recombinant gametes are __________-__________ and the genetic consequence is an absence of recombination within the __________ segment. |
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Definition
1) Dicentric bridges
2) Acentric fragments
3) Non-viable
4) Inverted |
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Term
The consequences of a crossover within a pericentric inversion lack __________ __________ (dicentric) or __________ __________. The recombinant gametes are non-viable just the same, because __________ and __________ are created once again.
Despite recombination within an inversion loop, four viable gametes may result if a two strand __________ crossover occurs with the sites of the two recombinations falling close to each other. |
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Definition
1) Bridge-chromosomes
2) Acentric fragments
3) Deletions
4) Duplications
5) Double |
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Term
| __________ are changes in a position of a chromosome segment. It may be __________ or between nonhomologous chromosomes. |
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Definition
1) Translocations
2) Intrachromosomal |
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Term
__________ translocation involves the movement of a segment within the same chromosome.
__________ translocations may be non-reciprocal (__________) or reciprocal (__________-__________) |
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Definition
1) Intrachromosomal
2) Interchromosomal
3) Unidirectional
4) Bidirectional |
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Term
__________ translocation will change gene orders and map-distances in the same linkage group.
During meiosis in heterozygotes for a translocation, pairing of homologous sequences produced unbalanced gametes that may be __________. |
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Definition
1) Intrachromosomal
2) Nonviable |
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Term
| __________ translocations are a special kind of non-reciprocal translocation in which two acrocentric chromosomes fuse to create a single chromosome with one centromere. |
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Definition
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Term
| When the expression of a gene is altered due to a change in its location in the genome the phenomenon is called __________ __________. |
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Definition
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Term
__________ has played an important role in plant separation.
Fusion of a diploid gamete with a normal haploid gamete produces a __________ individual.
Parthenogenesis yields a __________ individual.
Doubling the chromosome number of a plant using alkaloid colchine yields a __________ __________. |
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Definition
1) Polyploidy
2) Triplpoid
3) Haploid
4) Homozygous diploid |
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Term
| __________ is the result of failure of the cell division apparatus, a process called __________. |
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Definition
1) Polyploidy
2) Endoreduplication |
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Term
| __________ usually occurs as a result of mating between a diploid and a tetraploid individual. |
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Definition
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Term
| __________ results from formation of an individual from a gamete without fertilization. |
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Definition
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Term
| __________ is usually lethal (because of unmasking of lethal recessive mutations). |
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Definition
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Term
| Polyploids with an __________ number of chromosomes sets are more fertile than those with an __________ numbers of sets. |
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Definition
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Term
| In triploids, there is __________ for every chromosome. |
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Definition
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Term
| What are the two classes available in tetraploids? |
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Definition
1) Autotetraploid
2) Allotetraploid |
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Term
__________ have four copies of the same genome.
__________ have two copies each of two different genomes.
All __________ generally have better chromosome pairing and are more fertile than __________. |
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Definition
1) Autotetraploids
2) Allotetraploids
3) Allotetraploids
4) Autotetraploids |
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Term
| __________ have complex segragation patterns due to the presence of four copies of a gene. |
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Definition
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Term
| __________ behave like diploids. |
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Definition
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Term
| __________ denotes conserved arrangement of groups of linked genes between different related species. |
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Definition
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