CH 13 Chromosomal Basis Of Inheretiance

Question 1

Mendels “Hereditary factors”

Answer 1

We’re Genes

Question 2

Mitosis and Meiosis first discovered

Answer 2

Late 1800s

Question 3

Chromosome theory of inheritance

Answer 3

-Genes have specific loci(positions) on chromosomes
-Chromosomes undergo segregation and independent assortment

Question 4

Only Y Chromosomes have regions

Answer 4

That are homologous with corresponding regions of the X chromosomes

Question 5

SRY Gene

Answer 5

-on Y chromosomes
-required for testes development

Question 6

Sex linked traits

Answer 6

Governed by genes found on the sex chromosomes

Question 7

X-linked

Answer 7

-Color blindness
-Hemophilia
-Muscular dystrophy

Question 8

Y-linked

Answer 8

Hypertricosis

Question 9

For a reces X-linked trait to be expressed

Answer 9

-Female needs 2 copies of the allele(Homozygous)
-Male needs only one copy of the allele (hemizygous)

Question 10

Sex influenced traits

Answer 10

Genes found on the autonomies but dominant in one sex and recessive in the other

Question 11

Sex Limited Traits

Answer 11

Gene found on the autosomes but expressed in one sex

Question 12

Nondisjunction

Answer 12

Failure of homologues and sister chromatids to separate

Question 13

Down syndrome

Answer 13

Trisomy 21

Question 14

Patau syndrome

Answer 14

Trisomy 13

Question 15

Edward syndrome

Answer 15

Trisomy 18

Question 16

Klinefelter syndrome (male)

Answer 16

-poor beard growth
-breast development
-underdeveloped testes

Question 17

Turners Disease (Fmale)

Answer 17

-characteristic facial features
-web of skin
-constriction of aorta
-poor breast development
-underdeveloped ovaries

Question 18

Extranuclear Genes

Answer 18

Genes found in organelles, in the cytoplasm such as mitochondria and plastids
-no Mendel, not segregated during meiosis
-inherited maternally, zygote cytoplasm comes from egg

Question 19

Frederick Griffith

Answer 19

1928
-Provided evidence that the genetic material is specific molecule

Question 20

Hemizygous

Answer 20

Male X Chromosome has no active counterpart on Y chromosome

Question 21

Dosage compensation

Answer 21

Chromosomes inactivation, to prevent doubling up

Question 22

Barr Body

Answer 22

A deeply staining structure, seen in the interphase nucleus of a cell of an individual with more than one X chromosome,

Question 23

Genetic Mosaics

Answer 23

Individual cells may express different alleles, depending on which chromosomes is inactivated

Question 24

Maternal inheritance

Answer 24

Uniparental inheritance from the mother

Question 25

Genomic imprinting

Answer 25

The phenotype caused by a mutant allele is exhibited when the allele comes from one parent, but not when it comes from the other PWS AS