Variation In Chromosome

Front 1

Metacentric

Back 1

Centromere at the middle and has arms of equal length

Front 2

Submetacentric

Back 2

Centromere displaced at an end creating long and short arms

Front 3

Acrocentric

Back 3

Centromere near an end with long arm and knob/satellite

Front 4

Telocentric

Back 4

Centromere at or very near to end of chromosome

Front 5

Karyotype

Back 5

Complete set of chromosomes possessed by an organism

Front 6

Karyotype

Back 6

Usually presented as a picture of metaphase chromosomes lined up descendingly of size

Front 7

Ploidy

Back 7

Number of sets of chromosomes in cells

Front 8

Monoploid

Back 8

One set of chromosome

Front 9

Diploid

Back 9

Two sets of chromosome

Front 10

Polyploid

Back 10

More than three sets of chromosome

Front 11

Chromosome mutation categories

Back 11

1. Chromosome rearrangements

2. Aneuploids

3. Polyploids

Front 12

Chromosome rearrangements

Back 12

Alteration in chromosome structure

Front 13

Aneuploids

Back 13

Alteration in chromosome number

Front 14

Polyploids

Back 14

One or more complete sets of chromosome being added

Front 15

Duplication

Back 15

Doubled part of chromosome

Front 16

Tandem duplication

Back 16

Duplicated region is immediately adjacent to original segment

Front 17

Displaced duplication

Back 17

Duplicated region is located distance away from original segment either on same or different arm or chromosome

Front 18

Reverse duplication

Back 18

Inverted duplication or reverse repeat

Front 19

True

Back 19

An individual homozygous for duplication carries the duplicated region on both homologous chromosomes.

Front 20

False

Back 20

An individual heterozygous for duplication has two unmutated chromosomes and one chromosome with the duplicate.

Hint 20

One unmutated

Front 21

Synapsis

Back 21

Pairing of homologues to form tetrad at prophase I

Front 22

True

Back 22

In heterozygotes, problem arise in chromosome pairing at prophase I of meiosis because two chromosomes are not homologous to their length.

Front 23

False

Back 23

Mutation may not have major effects on phenotype due to imbalances of gene products.

Hint 23

Mutation may have effects

Front 24

Deletion

Back 24

Loss of chromosome segment

Front 25

True

Back 25

Deletion can be easily detected because of shortened chromosome.

Front 26

False

Back 26

Genotypic consequences depend on which genes are located in the deleted region.

Hint 26

Phenotypic. E.g. If including centromere, chromosomes won't segregate

Front 27

Reasons why heterozygous individuals with deletion have multiple defects

Back 27

1. Heterozygous condition may produce imbalances in the amounts of gene products

2. Pseudodominance

3. Haploinsufficient gene

Front 28

Pseudodominance

Back 28

Deleted dominant allele or expression of recessive mutation

Front 29

Haploinsufficient gene

Back 29

Single copy of gene is insufficient to make wildtype phenotype

Front 30

Inversions

Back 30

Chromosome segment is inverted by 180° and must break for it to occur

Front 31

Paracentric

Back 31

Does not include centromere when inverting

Front 32

Pericentric

Back 32

Includes centromere when inverting

Front 33

True

Back 33

Inversion often have pronounced phenotypic effect due to inverted gene order.

Front 34

Position effect

Back 34

Outcome of inversion

Front 35

True

Back 35

An individual homozygous for inversion won't result to special problem since the homologous chromosomes can pair and segregate randomly.

Front 36

Inversion loop

Back 36

A heterozygous individual for particular inversion will have two homologous chromosomes align and pair if they will form this

Front 37

True

Back 37

Reduced recombination along inverted region.

Front 38

Dicentric chromatid

Back 38

Chromatid that has two centromeres

Front 39

Acentric chromatid

Back 39

Chromatid that lacks centromere

Front 40

Translocation

Back 40

Movement of genetic material between nonhomologous chromosomes or within same chromosome

Front 41

Nonreciprocal

Back 41

Genetic material moved from one chromosome to another without any reciprocal exchange

Hint 41

Minsan translocation, minsan feelings niya sayu.

Front 42

Reciprocal

Back 42

Two-way exchange of segments between chromosomes

Front 43

Different effects on phenotype [translocation]

Back 43

1. Can create new linkage relations that affect gene expression or position effect

2. Disrupts the function of gene

Front 44

Robertsonian translocation

Back 44

Participating chromosomes break at their centromeres and long arms fuse to form single large chromosome with one centromere

Front 45

Causes of aneuploidy

Back 45

1. Chromosome may be lost during mm

2. Small chromosome generated by Robertsonian translocation be lost in mm

3. Due to nondisjunction or the failure of homologues/sister chromatids to separate in mm

Hint 45

Meiosis or mitosis (mm)

Front 46

Nullisomy

Back 46

Type of aneuploidy losing both members of homologous chromosomes

Front 47

Monosomy

Back 47

Type of aneuploidy losing one chromosome

Front 48

Trisomy

Back 48

Type of aneuploidy gaining one chromosone

Front 49

Tetrasomy

Back 49

Type of aneuploidy gaining two homologous chromosomes

Front 50

True

Back 50

More than one aneuploidy may occur in the same individual

Front 51

Uniparental disomy

Back 51

Individual with two copies of chromosome from one of the parent only

Front 52

Uniparental disomy

Back 52

May arise when trisomic embryo loses one of the triplicate chromosomes early in development

Front 53

Mosaicism

Back 53

Nondisjunction in mitotic division generating patches of cells with abnormal chromosome and other patches of normal karyotype

Front 54

Mosaicism

Back 54

Leads to region of tissue with different chromosome constitutions

Front 55

Somatic or meiotic

Back 55

Origin of trisomy mosaicism

Front 56

Mosaics

Back 56

1. Cells in organism have same genetic origins

2. Almost all loci are identical in different cell populations as all cells are derived from same zygotic genotype

3. Somatic mutations make us all mosaic

Front 57

Chimera

Back 57

1. One organism composed of genetically distinct cells

2. Chimerism have divergent genotypes all across the genome

3. They can be artificially produced from organ transplants of different animals

Front 58

Freemartinism

Back 58

Form of intersexuality arising from vasculat anastomosis of adjacent chorioallantoic sacs of male and female fetuses in multiple pregnancies

Front 59

Freemartinism

Back 59

Most commonly recognized non-inflammatory condition resulting to infertility involving tubular reproductive tract in bovine

Front 60

Freemartinism

Back 60

Has been demonstrated as a cause of infertility in heifers with apparently normal external genitalia but with sex chromosome chimerism

Front 61

Freemartin

Back 61

Infertile mammal with masculinized behavior and non-functioning ovaries

Front 62

Genetically the animal is chimeric.

Back 62

Karyotyping sample cells shows XX or XY chromosomes means

Front 63

Genetically the animal is chimeric and has microchimerism

Back 63

Animal originates as XX but gets XY component in utero by exchange of some cellular material from a male twin via vascular connections between placentas which means

Front 64

Genetically the animal is chimeric.

Back 64

Animal appears as XX but various reproductive development are altered due to acquiring anti-Müllerian hormone from the male twin

Front 65

True

Back 65

Freemartinism causes infertility in female cattle born twin to a male. When heifer twin shares uterus with a bull fetus, they also share placental membranes connecting them.

Front 66

True

Back 66

Estimates of percentage of natural beef cattle births that produce twins vary. One estimate puts percentage of 0.5% or 1 in every 200 births. Approximately half of the sets of twins should contain both a bull or heifer calf.

Front 67

Autopolyploidy

Back 67

Type of polyploidy wherein accidents of mm produce extra sets of chromosomes deriving from single spp

Front 68

Autotriploid or 3n

Back 68

May arise when nondisjunction in meiosis produces a diploid gamete that then fuses with normal haploid gamete forming triploid zygoye

Front 69

False

Back 69

In mitosis of autotriploid or 3n, homolohous chromosomes can pair or not pair in three ways.

Hint 69

Meiosis

Front 70

Allopolyploidy

Back 70

Arises from hybridization between two spp

Front 71

Allopolyploidy

Back 71

Resulting polyploid carries chromosome sets derived from two or more spp

Front 72

Mule

Back 72

Female horse plus male donkey

Front 73

Autopolyploidy

Back 73

-Chromosome complement consists of more than two copies of homologous chromosomes

-Arises by fusion of gametes of same spp

-Its cell contains homologous chromo sets

-Mainly caused by nondisjunction of chromosomes

-Don't undergo meiosis since it is from one parent

-Seen in crops like wheat, oats, sugar-cane, potato, peanut, banana, and coffee

Front 74

Allopolyploidy

Back 74

-Chromosome complement consist of more than two copies of chromosomes from different spp

-Arises by fusing gametes of different species

-All chromosome sets of its cell are not homologous

-Due to mating of different spp

-Can undergo meiosis

-Seen in crops like wheat and animals like mule

Front 75

Genetic rescue

Back 75

Introduction of new genetic variation into an inbred population

Front 76

Gene pool

Back 76

Stock of different genes in interbreeding population

Front 77

Plato

Back 77

No two persons are born exactly alike but each differs from the other in natural endowments, one being suited for one occupation and the other for another

Front 78

Johann Wolfgang von Goeche

Back 78

No two people see the world exactly alike, and different temperaments will often apply the same principle recognized by both differently. Even when one and same person won't always maintain the same views and judgements; earlier convictions must give way to later ones