Genetics Test 2

Front 1

Sry

Back 1

• A sex determining region of the Y

Front 2

Msy

Back 2

• The male specific region of the Y

Front 3

3-point mapping

Back 3

• the parent must be heterozygous for all 3 genes

Front 4

47, XXX(Triple X)

Back 4

• females are phenotypically perfectly normal

Front 5

Additive action

Back 5

• (9:6:1 phenotype)
• Heterozygous(A_/B_) will cause same thing

Front 6

Amniocentisis

Back 6

• culture skin cells and karyotype can be done

Front 7

Angelman Syndrome

Back 7

• is a neuro-genetic disorder characterized by intellectual delay, sleep disturbance, seizures, jerky movements(especially hand flapping), and frequent laughing or smiling

Front 8

Bivalent

Back 8

• 2 homologs

Front 9

chiasmata

Back 9

• points of genetic exchange

Front 10

chorionic villus sampling(CVS)

Back 10

• vacuum that goes to the chorionic villi and cuts out some. Can be done earlier but is more invasive

Front 11

chromosome mutations(chromosome aberarrations)

Back 11

• A change in the total # of chromosomes
• The deletion or duplication of genes or segments of a chromosome
• Rearrangements of the genetic material within or among the chromosomes

Front 12

Complementary action

Back 12

• (9:7 phenotype)
• Follows Mendel, but only 2 phenotypes
• The 7 is double recessive
• So you need two enzymes to get to the final product, so if one enzyme does not work, then you will not get to the final product

Front 13

Complementation

Back 13

• Two alleles of the same gene

Front 14

Conditional mutations

Back 14

• Mutations affected by temperature

Front 15

cri-du-chat syndrome

Back 15

• Partial autosomal monosomies have been reported

Front 16

Dosage compensation

Back 16

• balances the dose of X c’some gene expression in females and male

Front 17

Down Syndrome

Back 17

• results from trisomy of chromosome 21

Front 18

Duplicate action

Back 18

• (15:1 phenotype)
• Only when both genes are recessive, there will not be a contribution
• Ex. 2 copies of the same gene

Front 19

Edwards Syndrome

Back 19

• trisomy 18

Front 20

Epistasis

Back 20

• The effect of one gene masks or modifies the effect of another gene or gene pair

Front 21

Euploidy

Back 21

• complete haploid sets of chromosomes are present

Front 22

Expressivity

Back 22

• the extent of expression in an individual

Front 23

genetic anticipation

Back 23

• affected parent could have affected offspring, (ex. Huntington) the offspring has an earlier onset and stonger degree of expression

Front 24

genomic imprinting

Back 24

• phenotypic expression may depend on the parental origin of the chromosome(depends on which parent you received c’some from)

Front 25

hemizygous

Back 25

• possesiion of only one copy of genes in an otherwise diploid cell

Front 26

Inhibiting action

Back 26

• (3:13 phenotype)
• 3 is the dominant form and 13 is the non-dominant form
• If A is dominant and B is dominant/ If A is recessive and B is recessive = no pigment
• If A is dominant and B is recessive=pigment

Front 27

interlocus distance

Back 27

• The degree of crossing over between any 2 loci on a single chromosome is proportional to the distance between them

Front 28

Klinefelter syndrome

Back 28

• male genitalia
• more than 1 X c’some (usually XXY, or a 47, XXY karyotype)

Front 29

Linkage

Back 29

• Genes that do no assort independently that are on the same gene

Front 30

linkage group

Back 30

• Genes on the same chromosome

Front 31

male infertility

Back 31

• is controlled by the absence or presence of the Y c’some

Front 32

map unit(mu)

Back 32

• is defined as 1% recombination between 2 genes on a chromosome

Front 33

Masking action

Back 33

• (12:3:1 phenotype)
• Example, mixing black and yellow pigment
• Black and yellow lab will mix and still be black bc black is more dominant

Front 34

Modifying action

Back 34

• (9:3:4 phenotype)
• The first gene gives pigment or no pigment and the second gene gives more expression

Front 35

Non disjunction

Back 35

• in which chromosome or chromatids fail to disjoin and move to opposite poles during meiosis I(homologous c’somes separate) or meiosis II(chromatids)

Front 36

pseudo-autosomal region(PARS)

Back 36

• On both ends of the Y chromosome are the pseudo-autosomal regions(PARS) that share homology with regions on the X chromosome, and synapse and recombine with it during meiosis

Front 37

prader wii syndrome

Back 37

• is the most common known genetic cause of life threatening obesity on children

Front 38

Patau syndrome

Back 38

• trisomy 13

Front 39

Penetrance

Back 39

• the percentage of individuals in a pedigree that show at least some degree of expression

Front 40

Pleiotropy

Back 40

• When the expression of a single gene has multiple effects

Front 41

Polyploidy

Back 41

• occurs when >2 sets of chromosomes are present

Front 42

Primary Sex Ratio

Back 42

• reflects the proportion of male to female conceived in a population

Front 43

Secondary Sex Ratio

Back 43

• reflects the proportion of each sex that is born

Front 44

sex determination

Back 44

• is controlled by X c’some number = or > autosomal c’some number(number of sets) and

Front 45

Sex-Influenced Inheritance

Back 45

the sex of an individual influences the expression of a phenotype that is not, limited to one sex of the other(male pattern baldness)

Front 46

Sex-Limited inheritance

Back 46

• occurs in cases where the expression of a specific phenotype is limited to one sex single crossover(SCO)(dev. Of waddle in chicken )

Front 47

testis-determining factor(TDF)

Back 47

• is a protein encoded by a gene in the SRY that triggers testes formation.

Front 48

Trisomy (2n+1)

Back 48

• for the sex chromosomes has a less dramatic phenotype than trisomies for autosomes, which are often lethal
• Recall: (47, XXY; 47, XYY; 47 XXX)

Front 49

Trivalent

Back 49

• When 3 copies of a chromosome are synapsed the configuration

Front 50

Turner Syndrome

Back 50

• 1 X chromosome
• no Y chromosome (45, X karyotype)
• female genitalia

Front 51

univalent

Back 51

• an unpaired chromosome

Front 52

X-linkage

Back 52

• Genes present on the x chromosome exhibit different patterns than on the y chromosome

Front 53

XX/XO (butterly, Protenor) mode of sex determination

Back 53

• depends on the random distribution of the X c’some into ½ of all the male gametes

Front 54

XX/XY(lygaeus) mode of sex determination

Back 54

• Zygotes with the 2 X chromosomes(homogametous) result in females
• Zygotes with 1 x chromosome and 1 y chromosome

Front 55

XXY karyotype(Jacobs Syndrome)

Back 55

• is that such males are over 6 ft tall.

Front 56

ZZ/ZW sex determination

Back 56

• Female: heterogametic(ZW) sex
• Male: homogametic(ZZ) sex
• i.e. most birds but not all

Front 57

autopolyploidy

Back 57

• The addition of 1 or more sets of chromosomes identical to the haploid complement of the same species

Front 58

Allopolyploidy

Back 58

• Or the combination of chromosome sets from different species as a consequence of interspecific matings

Front 59

allotetraploid

Back 59

• arises form hybridization of 2 closely related species

Front 60

amphidiploid

Back 60

• occurs when the sterile hybrid undergoes a natural chromosomal doubling, a fertile is produced

Front 61

somatic cell hybridization

Back 61

• Dissolving the cell wall(cellulose) with cellulose and merge cells and dissolve the cell membrane

Front 62

Endopolyploidy

Back 62

• when some cells in an otherwise 2n organism are polyploidy

Front 63

Haploidy (monoploidy)(n)

Back 63

• has been observed(albeit rarely) in plants, but has been induced in many plant species through plant tissue culture techniques