Bio 181 topic 6- Questions and Answers
1. Wild type The normal character phenotype is the wild type.
2. Mutant Traits alternative to the wild type are called mutant phenotypes.
3. Chromosome Mendelian genes are at specific loci on the chromosome and in turn segregate
theory of during meiosis.
inheritance
4. X-linked traits Genes on the X chromosome are called X-linked genes; many characters unrelated
to sex.
5. Linked genes Genes located on the same chromosome, linked genes, tend to be inherited
together because the chromosome is passed along as a unit.
6. Gene mapping Alfred Surtevant: Morgan's student constructed a genetic map of the genetic loci
along a particular chromosome.
Determining the relative positions of genes on a chromosome by measuring
recombination frequencies—genes with higher recombination are farther apart,
and genes with lower recombination are closer together
7. Linkage map A genetic map of a chromosome based on recombination frequencies.
8. Map unit 1% recombination frequency (centimorgan).
, Bio 181 topic 6- Questions and Answers
9. Recombination The production of ottspring with new combinations of traits inherited from two
frequency parents is genetic recombination: Recombination frequency = (# recombinants) x
100 / total ottspring.
10. X-linked reces- Heterozygous females will be always carriers; males receiving the recessive allele
sive phenotype from their mother will express the trait.
inheritance pat- More common in males (only one X).
terns Attected sons usually come from carrier mothers.
Fathers cannot pass X-linked traits to sons.
Daughters can be carriers if father is attected and mother is normal or carrier.
11. Hemizygous Having only one copy of a gene instead of the usual two; typically refers to males
for X-linked genes because they have only one X chromosome.
Because males have only one X chromosome, any male receiving the recessive
allele from his mother will express the trait.
12. SRY gene A gene on the Y chromosome called SRY (sex-determining region on the Y) is
responsible for the development of the testes in an embryo.
1. Wild type The normal character phenotype is the wild type.
2. Mutant Traits alternative to the wild type are called mutant phenotypes.
3. Chromosome Mendelian genes are at specific loci on the chromosome and in turn segregate
theory of during meiosis.
inheritance
4. X-linked traits Genes on the X chromosome are called X-linked genes; many characters unrelated
to sex.
5. Linked genes Genes located on the same chromosome, linked genes, tend to be inherited
together because the chromosome is passed along as a unit.
6. Gene mapping Alfred Surtevant: Morgan's student constructed a genetic map of the genetic loci
along a particular chromosome.
Determining the relative positions of genes on a chromosome by measuring
recombination frequencies—genes with higher recombination are farther apart,
and genes with lower recombination are closer together
7. Linkage map A genetic map of a chromosome based on recombination frequencies.
8. Map unit 1% recombination frequency (centimorgan).
, Bio 181 topic 6- Questions and Answers
9. Recombination The production of ottspring with new combinations of traits inherited from two
frequency parents is genetic recombination: Recombination frequency = (# recombinants) x
100 / total ottspring.
10. X-linked reces- Heterozygous females will be always carriers; males receiving the recessive allele
sive phenotype from their mother will express the trait.
inheritance pat- More common in males (only one X).
terns Attected sons usually come from carrier mothers.
Fathers cannot pass X-linked traits to sons.
Daughters can be carriers if father is attected and mother is normal or carrier.
11. Hemizygous Having only one copy of a gene instead of the usual two; typically refers to males
for X-linked genes because they have only one X chromosome.
Because males have only one X chromosome, any male receiving the recessive
allele from his mother will express the trait.
12. SRY gene A gene on the Y chromosome called SRY (sex-determining region on the Y) is
responsible for the development of the testes in an embryo.
