Chapter 15 - Chromosomal Basis of Inheritance

Question 1

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

Answer 1

Chromosome Theory of Inheritance

Question 2

The phenotype most commonly observed in natural populations; also refers to the individual with that phenotype

Answer 2

Wild Type

Question 3

A gene located on either sex chromosome. Most of these genes are on the X chromosome and show distinctive patterns of inheritance; there are very few genes on the Y chromosome

Answer 3

Sex-Linked Gene

Question 4

A gene located on the X chromosome; such genes show a distinctive pattern of inheritance

Answer 4

X-linked gene

Question 5

A human genetic disorder caused by a sex-link recessive allele; characterized by progressive weakening and a loss of muscle tissue

Answer 5

Duchenne Muscular Dystrophy

Question 6

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 6

Hemophilia

Question 7

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

Answer 7

Barr Body

Question 8

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

Answer 8

Linked genes

Question 9

General term for the production of offspring with combinations of traits that differ from those found in either parent

Answer 9

Genetic recombination

Question 10

An offspring with a phenotype that matches one of the true-breeding parental (P generation) phenotypes; also refers to the phenotype itself

Answer 10

Parental types

Question 11

An offspring whose phenotype differs from that of the true-breeding P generation parents; also refers to the phenotype itself

Answer 11

Recombinant types/recombinants

Question 12

The reciprocal exchange of genetic material between nonsister chromatids during prophase 1 of meiosis

Answer 12

Crossing over

Question 13

An ordered list of genetic loci (genes or other genetic markers) along a chromosome

Answer 13

Genetic map

Question 14

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

Answer 14

Linkage map

Question 15

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

Answer 15

Map units

Question 16

An error in meiosis or mitosis in which members of a pair of homologs or a pair of sister chromatids fail to separate properly from each other

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 2 complete chromosome sets. It is the result of an accident of cell division.

Answer 20

Polyploidy

Question 21

A deficiency in a chromosome resulting from the loss of a fragment through breakage; a mutational loss of one or more nucleotide pairs from a gene

Answer 21

Deletion

Question 22

An aberration in chromosome structure due to fusion with a fragment from a homolog, such that a portion of a chromosome is duplicated

Answer 22

Duplication

Question 23

An aberration in chromosome structure resulting from reattachment of a chromosomal fragment in a reverse orientation to the chromosome from which it originated

Answer 23

Inversion

Question 24

An aberration in chromosome structure resulting from attachment of a chromosomal fragment to a nonhomologous chromosome

Answer 24

Translocation

Question 25

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

Answer 25

Down Syndrome

Question 26

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

Answer 26

Genetic imprinting