BIOLOGY
YEAR 2
QUARTER 2
2020
Genetics
SUMMARY OF THE COURSE GENETICS
NWI-BB091
ELISE REUVEKAMP
,Inhoud
Lecture 1: Meiosis and Mendelian genetics...........................................................................................2
Mendelian genetics............................................................................................................................2
Meiosis vs mitosis...............................................................................................................................2
Lecture 2: More complex Mendelian genetics.......................................................................................6
Gene interaction:................................................................................................................................6
Deducing gene interaction strategies:................................................................................................6
Lecture 3: Population Genetics...............................................................................................................8
Gene pool...........................................................................................................................................8
Change of genetic variation................................................................................................................9
Selection...........................................................................................................................................10
Lecture 4: Quantitative genetics...........................................................................................................12
Quantitative Variance.......................................................................................................................12
Changes of quantitative traits...........................................................................................................12
Lecture 5: Linkage analysis (mapping)..................................................................................................15
Are the genes linked?.......................................................................................................................15
Trihybrid linkage analysis:.................................................................................................................17
Interference......................................................................................................................................18
Markers............................................................................................................................................18
Lecture 6: Large-scale chromosomal changes......................................................................................21
QTL = quantitative trait loci..............................................................................................................21
Chromosomal changes.....................................................................................................................22
Important findings from the tutorials...................................................................................................24
, Lecture 1: Meiosis and Mendelian genetics
Mendelian genetics
Mendelian genetics refers to an inheritance pattern that follows the laws of segregation and
independent assortment in which a gene inherited from either parent segregates into gametes at an
equal frequency.
Mendel’s Laws:
1. Law of uniformity when two pure lines (homozygous) that differ for one characteristic are
crossed, the appearance of the F1-progeny will be uniform. (AAxaa)
2. Law of equal segregation When individuals from the first uniform F1 generation are
crossed, the features of the parents and F1 will appear in a ratio of 3:1 or 1:2:1
3. Law of independent assortment Genes for different traits are sorted separately from one
another so that the inheritance of one trait is not dependent on the inheritance of another
Meiosis vs mitosis
Meiosis and fertilization contribute to genetic variation in offspring.
Mitosis produces identical genetic material that is passed on to cellular offspring (asexual
reproduction)
The three types of sexual life cycles
1. Diplontic – mitosis only occurs diploid cells (diploid stage is multicellular)
2. Haplo-diplontic – mitosis occurs in diploid and haploid cells (diploid + haploid stage is
multicellular)
3. Haplontic – mitosis only occurs in haploid cells (haploid stage is multicellular
Haploid gametes contain 22 autosomes and one sex chromosome.
Diploid cells contain 44 autosomes and 2 sex chromosomes. In total
you have 46 chromosomes.
Homologous chromosomes are the chromosomes that have the same
gene sequences. One homologous chromosome is inherited from the
organism’s mother and the other is inherited from the organisms
father.
Chromosome is a DNA molecule packed together with proteins.
Chromosome structure:
- Double helix of DNA
- Histones (proteins to package DNA)
- Nucleosome (DNA and histones complex)
- Chromatin (DNA strans and chromosomal proteins)
- Chromatid (one of the legs of a chromosome)
YEAR 2
QUARTER 2
2020
Genetics
SUMMARY OF THE COURSE GENETICS
NWI-BB091
ELISE REUVEKAMP
,Inhoud
Lecture 1: Meiosis and Mendelian genetics...........................................................................................2
Mendelian genetics............................................................................................................................2
Meiosis vs mitosis...............................................................................................................................2
Lecture 2: More complex Mendelian genetics.......................................................................................6
Gene interaction:................................................................................................................................6
Deducing gene interaction strategies:................................................................................................6
Lecture 3: Population Genetics...............................................................................................................8
Gene pool...........................................................................................................................................8
Change of genetic variation................................................................................................................9
Selection...........................................................................................................................................10
Lecture 4: Quantitative genetics...........................................................................................................12
Quantitative Variance.......................................................................................................................12
Changes of quantitative traits...........................................................................................................12
Lecture 5: Linkage analysis (mapping)..................................................................................................15
Are the genes linked?.......................................................................................................................15
Trihybrid linkage analysis:.................................................................................................................17
Interference......................................................................................................................................18
Markers............................................................................................................................................18
Lecture 6: Large-scale chromosomal changes......................................................................................21
QTL = quantitative trait loci..............................................................................................................21
Chromosomal changes.....................................................................................................................22
Important findings from the tutorials...................................................................................................24
, Lecture 1: Meiosis and Mendelian genetics
Mendelian genetics
Mendelian genetics refers to an inheritance pattern that follows the laws of segregation and
independent assortment in which a gene inherited from either parent segregates into gametes at an
equal frequency.
Mendel’s Laws:
1. Law of uniformity when two pure lines (homozygous) that differ for one characteristic are
crossed, the appearance of the F1-progeny will be uniform. (AAxaa)
2. Law of equal segregation When individuals from the first uniform F1 generation are
crossed, the features of the parents and F1 will appear in a ratio of 3:1 or 1:2:1
3. Law of independent assortment Genes for different traits are sorted separately from one
another so that the inheritance of one trait is not dependent on the inheritance of another
Meiosis vs mitosis
Meiosis and fertilization contribute to genetic variation in offspring.
Mitosis produces identical genetic material that is passed on to cellular offspring (asexual
reproduction)
The three types of sexual life cycles
1. Diplontic – mitosis only occurs diploid cells (diploid stage is multicellular)
2. Haplo-diplontic – mitosis occurs in diploid and haploid cells (diploid + haploid stage is
multicellular)
3. Haplontic – mitosis only occurs in haploid cells (haploid stage is multicellular
Haploid gametes contain 22 autosomes and one sex chromosome.
Diploid cells contain 44 autosomes and 2 sex chromosomes. In total
you have 46 chromosomes.
Homologous chromosomes are the chromosomes that have the same
gene sequences. One homologous chromosome is inherited from the
organism’s mother and the other is inherited from the organisms
father.
Chromosome is a DNA molecule packed together with proteins.
Chromosome structure:
- Double helix of DNA
- Histones (proteins to package DNA)
- Nucleosome (DNA and histones complex)
- Chromatin (DNA strans and chromosomal proteins)
- Chromatid (one of the legs of a chromosome)
