Chapter 12

Question 0

The phenotype for a character most commonly observed in natural populations

Answer 0

Wild type

Question 1

A principle stating that genes are located at specific positions (loci) on chromosomes and that the behavior of chromosomes during meiosis accounts for inheritance patterns

Answer 1

Chromosome theory of inheritance

Question 2

A gene located on either sex chromosome

Answer 2

Sex-linked gene

Question 3

A gene located on the X chromosome

Answer 3

X-linked gene

Question 4

A human genetic disease cause by a sex-linked recessive allele; progressive weakening and loss of muscle tissue

Answer 4

Duchenne muscular dystrophy

Question 5

A human genetic disease caused by a recessive allele; absence of one or more blood-clotting proteins, excessive bleeding following injury

Answer 5

Hemophilia

Question 6

A dense object lying along the inside of the nuclear envelope in cells of female mammals, representing a highly condensed, inactivated X chromosome

Answer 6

Barr body

Question 7

Genes located close enough together on a chromosome that they tend to be inherited together

Answer 7

Linked genes

Question 8

The production of offspring with combinations of traits that differ from those found in either P generation parent

Answer 8

Genetic recombination

Question 9

An offspring with a phenotype that matches one of the true-breeding parental phenotypes

Answer 9

Parental types

Question 10

An offspring whose phenotype differs from that of a true-breeding P generation parents

Answer 10

Recombinant types (recombinants)

Question 11

The reciprocal exchange of genetic material between nonsister chromatids during prophase I of meiosis

Answer 11

Crossing over

Question 12

An ordered list of genetic loci along a particular chromosome

Answer 12

Genetic map

Question 13

A genetic map based on the frequencies of recombination between markers during crossing over of homologous chromosomes

Answer 13

Linkage map

Question 14

A measurement of the distance between genes. One of these is equivalent to a 1% recombination frequency

Answer 14

Map units

Question 15

A map of a chromosome that locates genes with respect to chromosomal features distinguishable in a microscope

Answer 15

Cytogenetic maps

Question 16

When the members of homologous chromosomes do not move apart properly during meiosis I or sister chromatids fail to separate during meiosis II

Answer 16

Nondisjunction

Question 17

A chromosomal aberration in which one or more chromosomes are present in extra copies or are deficient in number

Answer 17

Aneuploidy

Question 18

Referring to a diploid cell that has only one copy of a particular chromosome instead of the normal two

Answer 18

Monosomic

Question 19

Referring to a diploid cell that has three copies of a particular chromosome instead of the normal two

Answer 19

Trisomic

Question 20

A chromosomal alteration in which the organism possesses more than two complete chromosome sets. Results in an accident in cell division

Answer 20

Polyploidy

Question 21

An alteration in a chromosome that occurs when a chromosomal fragment is lost

Answer 21

Deletion

Question 22

An alteration in a chromosome when a deleted fragment attaches as an extra segment to a sister chromatid

Answer 22

Duplication

Question 23

An alteration in a chromosome when a chromosomal fragment reattaches to the original chromosome but in reverse orientation

Answer 23

Inversion

Question 24

An alteration in a chromosome when a fragment joins a nonhomologous chromosome

Answer 24

Translocation

Question 25

A human genetic disease usually caused by the presence of an extra chromosome 21; developmental delays that are generally treatable and non-life threatening

Answer 25

Down Syndrome