CH 15

Question 1

chromosome theory of inheritance

Answer 1

-states that genes are located at specific positions on chromosomes and that behavior is based on inheritance patterns

Question 2

wild type

Answer 2

-phenotypes that were commonly observed in natural populations

Question 3

sex-linked gene

Answer 3

-A gene that is located on either sex chromosome

Question 4

X-linked genes

Answer 4

-Genes on the X chromosome
-X chromosome has about 1100 genes

Question 5

Duchenne muscular dystrophy

Answer 5

-characterized by a progressive weakening of the muscles and loss of coordination

Question 6

Hemophilia

Answer 6

-x linked recessive disorder
-absence of one or more proteins required for blood clotting

Question 7

Barr body

Answer 7

• inactive X condensed

Question 8

linked genes

Answer 8

-Genes that are located on the same chromosome tend to be inherited together

Question 9

genetic recombination

Answer 9

-production of offspring with combinations of traits differing from either parent

Question 10

parental types

Answer 10

-Offspring with a phenotype matching one of the parental (P) phenotypes

Question 11

recombinant types/recombinants

Answer 11

-Offspring with nonparental phenotypes (new combinations of traits)

Question 12

crossing over

Answer 12

-accounts for the recombination of linked genes

Question 13

genetic map

Answer 13

-an ordered list of the genetic loci along a particular chromosome

Question 14

linkage map

Answer 14

-a genetic map of a chromosome based on recombination frequencies

Question 15

map units

Answer 15

-Distances between genes
-one map unit represents a 1% recombination frequency

Question 16

nondisjunction

Answer 16

-pairs of homologous chromosomes do not separate normally during meiosis

Question 17

Aneuploidy

Answer 17

-results from the fertilization of gametes in which nondisjunction occurred

Question 18

monosomic zygote

Answer 18

-only one copy of a particular chromosome

Question 19

trisomic zygote

Answer 19

-three copies of a particular chromosome

Question 20

Polyploidy

Answer 20

-a condition in which an organism has more than two complete sets of chromosomes

Question 21

Deletion

Answer 21

-removes a chromosomal fragment

Question 22

Duplication

Answer 22

-repeats a segment

Question 23

Inversion

Answer 23

-reverses orientation of a segment within a chromosome

Question 24

Translocation

Answer 24

-moves a segment from one chromosome to another

Question 25

Down syndrome

Answer 25

-an aneuploid condition that results from three copies of chromosome 21

Question 26

genomic imprinting

Answer 26

-Such variation in phenotype depends on which parent passed along the alleles for those traits