Chapter 15: The Chromosomal Basis Of Inheritance

Question 1

Chromosome Theory of Inheritance

Answer 1

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

Question 2

Hemophilia

Answer 2

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

Question 3

Barr Body

Answer 3

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

This is because one of the X chromosomes in females is deactivated

Question 4

Linked genes

Answer 4

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

Question 5

Genetic recombination

Answer 5

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

Question 6

Parental types

Answer 6

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

Question 7

Recombinant type

Answer 7

An offspring whose phenotype differs from that of the true breeding P generation Parents

Question 8

Genetic Map

Answer 8

An ordered list of genetic loci along a chromosome

Question 9

Linkage Map

Answer 9

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

Question 10

Map units

Answer 10

A unit of measurements of the distance between genes. one map unit is equivalent to 1% recombination frequency

Question 11

Nondisjunction

Answer 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

Question 12

Aneuploidy

Answer 12

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

Question 13

Monosomic

Answer 13

Referring to a diploid cell that has only one copy of a particular chromosome instead of the normal 2

Question 14

Trisomic

Answer 14

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

Question 15

Polyploidy

Answer 15

A chromosomal alteration in which the organism possessed more than two complete chromosome sets. It is the result of an accident of cell division

Question 16

Deletion

Answer 16

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

Question 17

Duplication

Answer 17

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

Question 18

Inversion

Answer 18

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

Question 19

Translocation

Answer 19

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

Question 20

Down syndrome

Answer 20

A human genetic diseases usually caused by the presence of an extra chromosome 21

Question 21

Genomic imprinting

Answer 21

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

Question 22

Sex linked gene

Answer 22

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

Question 23

X linked gene

Answer 23

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