Ch. 15 Vocab

Question 1

A gene located on a sex chromosome, resulting in a distinctive pattern of inheritance

Answer 1

sex-linked genes

Question 2

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

Answer 2

Duchenne muscular dystrophy

Question 3

a human genetic disease caused by a sex-linked recessive allele resulting in the absence of one or more blood-clotting proteins; characterized by excessive bleeding following injury

Answer 3

Hemophilia

Question 4

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

Answer 4

Barr body

Question 5

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

Answer 5

linked genes

Question 6

an offspring whose phenotype differs from that of the parents; also refers to the phenotype itself

Answer 6

Recombinant

Question 7

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

Answer 7

crossing over

Question 8

an ordered list of genetic loci along a chromosome

Answer 8

Genetic map

Question 9

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

Answer 9

linkage map

Question 10

a unit of measurement of the distance between genes

Answer 10

map units

Question 11

an error in meiosis or mitosis in which members of a pair of homologous chromosomes or a pair of sister chromatids fail to separate properly from each other

Answer 11

nondisjunction

Question 12

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

Answer 12

aneuploidy

Question 13

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

Answer 13

monosomic

Question 14

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

Answer 14

trisomic

Question 15

a chromosomal alteration in which the organism possesses more than two complete chromosome sets; the result of an accident of cell division

Answer 15

polyploidy

Question 16

a human genetic disease caused by the presence of an extra chromosome 21; characterized by mental retardation and heart and respiratory defects

Answer 16

Down syndrome

Question 17

a phenomenon in which expression of an allele in offspring depends on whether the allele is inherited from the male or female parent

Answer 17

genomic imprinting

Question 18

a basic principle in biology stating that genes are located on chromosomes and that the behavior of chromosomes during meiosis accounts for inheritance patterns

Answer 18

chromosome theory of inheritance