BIO 260 Linkage
1. Alleles segregate into their gametes equally (1⁄2 of gametes A; 1⁄2 a)
• The alleles at one gene don't affect the segregation of alleles at a different
gene. Ex. Aa Bb
-(independent assortment: 1⁄4 A B; 1⁄4 A b; 1⁄4 a B; 1⁄4 a b)
-works if each gene has its own chromosome: Mendel postulated (assumed):
2. 1000s of genes; only a few chromosomes, thus some genes are closely linked
(on same chromosome) and don't assort independently.: What is the reality of what
Mendel postulated?
3. Gene Linkage: The tendency of close genes on a chromosome to be inherited together (NOT independent
assortment).
ex. Aa Bb individual
-linked A and B genes results in more AB and ab gametes than aB/Ab
4. Crossing Over: process of mixing/'recombining' alleles at 2 loci
5. Recombination: the genetic process by which one chromosome breaks off and attaches to another chromo-
some during reproductive cell division
-crossing over
6. 1. Due to far distance and crossing over between genes 1 and 2
2. Are on different chromosomes: What are reasons genes are not linked?
7. Opposite: Crossing over and linkage are processes
8. shuffles; keeps; together: Crossing over genes within a chromosome, linkages
genes
9. low: If genes are close together, the likelihood of a crossing over event is:
1/3
, 10. High: If genes are distant, the likelihood of a crossing over event is:
11. Map Unit: Indicates the distance between 2 genes on a chromosome
12. 1 map unit: a 1% chance of a CO b/n 2 genes =
13. Autosomal Linked Genes: Genes that are linked on non-sex chromosomes
-dihibryid cross doesn't follow 9:3:3:1 ratio
-all gametes are not equally likely
- combos of parental alleles are most common
14. Parental Offspring: have same look/phenotype as P (parent) generation
2/3
1. Alleles segregate into their gametes equally (1⁄2 of gametes A; 1⁄2 a)
• The alleles at one gene don't affect the segregation of alleles at a different
gene. Ex. Aa Bb
-(independent assortment: 1⁄4 A B; 1⁄4 A b; 1⁄4 a B; 1⁄4 a b)
-works if each gene has its own chromosome: Mendel postulated (assumed):
2. 1000s of genes; only a few chromosomes, thus some genes are closely linked
(on same chromosome) and don't assort independently.: What is the reality of what
Mendel postulated?
3. Gene Linkage: The tendency of close genes on a chromosome to be inherited together (NOT independent
assortment).
ex. Aa Bb individual
-linked A and B genes results in more AB and ab gametes than aB/Ab
4. Crossing Over: process of mixing/'recombining' alleles at 2 loci
5. Recombination: the genetic process by which one chromosome breaks off and attaches to another chromo-
some during reproductive cell division
-crossing over
6. 1. Due to far distance and crossing over between genes 1 and 2
2. Are on different chromosomes: What are reasons genes are not linked?
7. Opposite: Crossing over and linkage are processes
8. shuffles; keeps; together: Crossing over genes within a chromosome, linkages
genes
9. low: If genes are close together, the likelihood of a crossing over event is:
1/3
, 10. High: If genes are distant, the likelihood of a crossing over event is:
11. Map Unit: Indicates the distance between 2 genes on a chromosome
12. 1 map unit: a 1% chance of a CO b/n 2 genes =
13. Autosomal Linked Genes: Genes that are linked on non-sex chromosomes
-dihibryid cross doesn't follow 9:3:3:1 ratio
-all gametes are not equally likely
- combos of parental alleles are most common
14. Parental Offspring: have same look/phenotype as P (parent) generation
2/3
