Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
|
Linked genes |
genes that are close together on the same chromosome, do not exhibit independent assortment during meiosis; genes located on sex chromosomes |
|
|
Unlinked genes |
exhibit independent assortment because they are on different chromosomes |
|
|
Wild type |
Individual with a "normal" phenotype |
|
|
Parentals |
Offspring that appear just like the parents |
|
|
Recombinants |
Offspring that are different from the parents (different allele makeup) |
|
|
Crossover |
Accounts for recombination in offspring, as breaks in parental chromosomes may form new allele linkages |
|
|
Results of fly cross -- independent assortment |
50/50 parental/recombinant |
|
|
Results of fly cross -- if linked and no crossing over |
100% parental |
|
|
Results of fly cross -- if linked and crossing over |
Frequency of recombinants depends on frequency of crossing over events |
|
|
Hemophilia |
X-linked recessive disorder; absence of one or more proteins required for blood clotting |
|
|
Recombination frequency |
Chances that crossing over will occur; farther apart the two genes are |
|
|
Map units |
Unit for recombination frequency; 1% of recombination frequency |
|
|
Sex-linked genes |
Genes located on sex (X) chromosomes |
|
|
Term used to describe alleles of sex chromosomes for men |
Hemizygous |
|
|
Parent(s) from which male receive X-linked traits |
Mother only |
|
|
Barr Body |
Inactivated X-chromosome in females |
|
|
Alterations in chromosome number |
Due to meiosis |
|
|
Alterations in chromosome structure |
Due to chemical reactions |
|
|
Nondisjunction |
1. Pair of homologous chromosomes do not move apart during Meiosis I or 2. Sister chromatids fail to separate during Meiosis II |
|
|
Consequences of Nondisjunction |
One gamete receives two copies of same chromosome and another gamete receives none at all |
|
|
Aneuploidy |
If a gamete with extra chromosome/none at all unites with a normal gamete in fertilization |
|
|
Trisomic aneuploidy |
2n+1; chromosome is present in triplicate |
|
|
Monosomic aneuploidy |
2n-1; chromosome is missing |
|
|
Down's Syndrome (trisomy 21) |
Extra copy of 21st chromosome; short stature, mental retardation, heart defects |
|
|
Klinefelter Syndrome |
Feminine characteristics and sterility in males |
|
|
Turner Syndrome |
Monosomic form of aneuploidy; sterility and physical deformations in women |
|
|
Deletion |
removal of a chromosomal segment |
|
|
Duplication |
repetition of a chromosomal segment |
|
|
Inversion |
reversal of a segment within a chromosome |
|
|
Translocation |
movement of a segment from one chromosome to another |
