5-4 Vocab

Question 1

Pedigree

Answer 1

A diagram of a family tree with conventional symbols, showing the occurrence of heritable characters in parents and offspring over multiple generations

Question 2

Multifactorial

Answer 2

Referring to a phenotypic character that is influenced by multiple genes and environmental factors

Question 3

Polygenic Inheritance

Answer 3

An additive effect of two or more genes on a single phenotypic character

Question 4

True breeding

Answer 4

Referring to organisms that produce offspring of the same variety over many generations of self-pollination

Question 5

Sickle-cell Disease

Answer 5

A recessively inherited human blood disease in which a single nucleotide change in the β-globin gene causes hemoglobin to aggregate, changing red blood cell shape and causing multiple symptoms in affected individuals

Question 6

Character

Answer 6

An observable heritable feature that may vary among individuals

Question 7

Incomplete Dominance

Answer 7

The situation in which the phenotype of heterozygotes is intermediate between the phenotypes of individuals homozygous for either allele

Question 8

Deletion

Answer 8

(1) A deficiency in a chromosome resulting from the loss of a fragment through breakage. (2) A mutational loss of one or more nucleotide pairs from a gene

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

Nondisjunction

Answer 10

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

Question 11

Map units

Answer 11

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

Question 12

Chromosome theory of inheritance

Answer 12

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

Question 13

Barr Body

Answer 13

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

Question 14

Parental Types

Answer 14

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

Question 15

Trisomic

Answer 15

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

Question 16

Wild Type

Answer 16

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

Question 17

Sex-linked gene

Answer 17

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 18

Hemophilia

Answer 18

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 19

Inversion

Answer 19

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

Question 20

Recombinant Types

Answer 20

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