Chapter 7 Vocab Flashcards
1
Q
genetic map
A
- (also referred to as a genetic linkage map) a diagram that shows the relative locations of genes or other DNA segments on a chromosome
2
Q
synteny
A
- A situation in which two or more genes are located on the same chromosome
3
Q
linkage group
A
- A group of genes that are linked together because they are found on the same chromosome
4
Q
two-factor cross
A
- A cross in which an experimenter follows the outcome of two different traits
5
Q
three-factor cross
A
- A cross in which an experimenter follows the outcome of three different traits
6
Q
crossing over
A
- A physical exchange of chromosome pieces that most commonly occurs during prophase of meiosis I
7
Q
bivalent
A
- A structure in which two pairs of homologous sister chromatids have synapsed (i.e., aligned) with each other
8
Q
Nonrecombinant
A
- 1) a gamete or offspring in which the arrangement of particular alleles on a chromosome have not been altered by a crossover
- exhibit parental phenotypes
9
Q
Recombinant
A
- 1) refers to combinations of alleles or traits that are not found in the true-breeding parental generation
- 2) in a testcross, a phenotype or arrangement of alleles on a chromosome that occurs in the offspring but is not found in the parental generation
10
Q
recombinant offspring
A
- With regard to linkage studies, offspring that are produced by the exchange of DNA between two homologous chromosomes during meiosis in one or both parents, leading to a novel combination of genetic material
11
Q
Null hypothesis
A
- A hypothesis that assumes there is no real difference between the observed and expected values
12
Q
Genetic map
A
- (also referred to as a genetic linkage map) a diagram that shows the relative locations of genes or other DNA segments on a chromosome
13
Q
locus
A
- The physical location of a gene or other DNA segment within a chromosome
14
Q
testcross
A
- An experimental cross between a recessive individual and an individual whose genotype the experimenter wishes to determine
-homozygous recessive individual and a corresponding suspected heterozygote to determine the genotype of the latter.
15
Q
map distance
A
- The physical distance between sites (e.g., genes) on a single chromosome
16
Q
map unit (mu)
A
- A unit of map distance obtained from genetic crosses. One map unit is equivalent to 1% recombinant offspring in a testcross
17
Q
centiMorgan (cM)
A
- (same as a map unit) a unit of map distance obtained from genetic crosses
Named in honor of Thomas Hunt Morgan
18
Q
mapping functions
A
- Approaches to determine the quantitative relationship between recombination frequencies and physical distances along chromosomes
19
Q
mitotic recombination
A
- Production of a pair of chromosomes that have a new combination of alleles due to crossing over that occurs during mitosis.
20
Q
Map distance formula
A
- Map distance = (# of recombinant offspring/ total number of offspring), X 100
-1 map unit (cM) = 1% recombination (recomb. frequency)
21
Q
A
