Chapter 8: Variation In Chromosome Structure And Number

Front 1

Terminal depletion

Back 1

When a segment is lost from the end of a chromosome

Front 2

Interstitial depletion

Back 2

Internal segment is lost from a chromosome

Front 3

Repetitive sequence

Back 3

DNA sequences that repeated in a genome

Front 4

Nonallelic homologous recombination

Back 4

Occurs within chromosomes due to repetitive sequences

Front 5

Gene Duplication

Back 5

Genetic material duplicated, with multiple copies of the region

Front 6

Gene Family

Back 6

Genes within a single (homologous) species that are derived from the same ancestral gene

Front 7

Homlologous

Back 7

Chromosomes having the same structural features and pattern of genes.

Front 8

Paralogs

Back 8

(Homologous) Genes related by duplication within a genome

Front 9

Copy of Number Variation
(CNV)

Back 9

Segment of DNA varying in copy numbers of the same species on a population level

Front 10

Segment Duplication

Back 10

Small segment of a chromosome that has another copy of the same gene (Ex. Two "A" Genes)

Front 11

Comparative Genomic Hybridization

(CGH)

Back 11

A technique to find depletion or duplication on a chromosome

Front 12

Hybridization

Back 12

1) Mating of same species with different characteristics

2) Two single stranded molecules renature to form a hybrid molecule

Front 13

Genetic Variation

Back 13

Genetic differences of same species or different species

Front 14

Allelic Variation

Back 14

Variation in specific genes

Front 15

Cytogeneticist

Back 15

Scientists that study chromosomes microscopically

Front 16

Metacentric

Back 16

Centromere is near the center

Front 17

Submetacentric

Back 17

Centromere is slightly off-centered

Front 18

Acrocentric

Back 18

Centromere significantly off center but not on the end

Front 19

Telocentric

Back 19

Centromere is at one end

Front 20

Karyotype

Back 20

Simple picture of a persons chromosomes in standard fashion via a micrograph

Front 21

G-Banding

Back 21

Giemsa dye used to observe banding pattern in chromosomes

Front 22

Pericentric Inversion

Back 22

Centromere lie within the inverted region

Front 23

Paracentric Inversion

Back 23

Centromere is found outside the inverted region

Front 24

Position Effect

Back 24

Change in phenotype when a gene position changes to another site on the chromosome

Front 25

Inversion Heterozygote

Back 25

Organism with one normal and one inverted chromosome

Front 26

Inversion Loop

Back 26

Homologous genes on both chromosomes align despite inverted sequence

Front 27

Acentric Fragment

Back 27

Chromosome without centromere

Front 28

Dicentric Fragment

Back 28

Chromosome with two centromeres

Front 29

Dicentric Bridge

Back 29

Region of the chromosomes where two centromeres connect

Front 30

Telomeres

Back 30

Prevents translocations; specialized repeated sequences of DNA

Front 31

Balanced Translocations

Back 31

Unaltered of total genetic material

Front 32

Unbalanced Translocations

Back 32

Large amounts of duplicated and/or deleted genetic material

Front 33

Roberstonian Translocation

Back 33

Breaks near the centromeres of two non-homologous acrocentric chromosomes

Front 34

Translocation Cross

Back 34

Occurs due to translocations, an unusual structure formed during meiosis for homologous chromosomes to synapse with each other.

Front 35

Semisterility

Back 35

When an individual has a lowered fertility

Front 36

Haplodiploid

Back 36

Where in some organisms one sex is haploid and the other is diploid (Ex. Bees)

Front 37

Endopolyploidy

Back 37

In a diploid individual, the phenomenon in which certain cells of the body may be polyploid

Front 38

Polytene chromosome

Back 38

Homologous chromosomes synapse and undergo replication, without separating

Front 39

Chromocenter

Back 39

The central point where polytene chromosomes aggregate

Front 40

Deletion

Back 40

A missing segment of chromosomal material

Front 41

Deficiency

Back 41

Missing region of a chromosome

Front 42

Duplication

Back 42

A repeated section of a chromosome

Front 43

Inversion

Back 43

Change of direction of genetic material on a single chromosome

Front 44

Translocation

Back 44

Segment of a chromosome that attaches to a different chromosome or moved to a different spot on the same chromosome

Front 45

Simple Translocation

Back 45

Single piece of a chromosome attached to another chromosome

Front 46

Reciprocal Translocation

Back 46

Two different chromosomes exchange pieces, producing abnormal chromosomes

Front 47

Euploid

Back 47

Organism with a chromosome number that is an exact multiple of a chromosome set

Front 48

Triploid

Back 48

Organism with three sets of chromosomes

Front 49

Tetraploid

Back 49

Organism with four sets of chromosomes

Front 50

Aneuploidy

Back 50

Number of chromosomes is not an exact multiple of a set in an organism

(Think opposite of Euploid)

Front 51

Trisomic

Back 51

Diploid with an extra chromosome

Front 52

Monosomic

Back 52

Diploid missing a chromosome

Front 53

Nondisjunction

Back 53

When chromosomes don't segregate properly

Front 54

Meiotic Nondisjunction

Back 54

Improper separation of chromosomes during meiosis

Front 55

Alloploid

Back 55

Organism containing sets of chromosomes from two or more different species

Front 56

Allodiploid

Back 56

Formed from closely related species carrying homeologus chromosomes

Front 57

Allotetraploid

Back 57

Two sets of chromosomes from two different species, total of four sets.

Front 58

Complete Nondisjunction

Back 58

Rare case of chromosomes undergo nondisjunction and migrate to a daughter cell

Front 59

Mosaicism

Back 59

Organism with a subset of cells genetically different from the rest of the organism

Front 60

Autopolyploid

Back 60

Individual with one or more extra set of chromosomes due to a defect in the spindle appparatus

Front 61

Homeologous

Back 61

Evolutionarily related chromosomes from two different species

(Not to be confused with homologous chromosomes!)