Molecular biology and genetics
02/10/18
- Heritability: the proportion of the variation in a population that is attributable to genetic
difference.
- Formula
- Can be calculated by comparing the variance of phenotype, in monozygotic vs dizygotic twins
- Meiosis – allows genetic variation. Prophase 1 of meiosis crossing over recombination happens.
Crossing over and recombination happens.
- Phenotype can also disease status, eg: diabetes and subject to migraines.
- A phenotypic train is a single observed parameter – can be inherited, environmental or a
combination.
Mendel
- Pea – demonstrating dominant inheritance of red flowers. – so which ones dominant and which
recessive
Mendelian train
- Simple phenotype classes
- Additive trains – heterozygotes have an intermediate phenotype
- Dominant – two not required.
- Some part of gene encodes for an RNA transcripts – can have its own biological activity eg: rRNA
and tRNA – or can be mRNA which encodes for a protein.
- The common allele is major and the less common allele is minor.
- The major allele is often referred to as wildtype.
- Locus = location of allele on a chromosome.
Inheritance can be 3 type
1) Recessive – 1/4
2) Dominant – 1/2
3) Sex – linked. – usually only males affected, and it can skip a generation.
Consequences of inheritance
- We can predict the possible genotype of offspring
- If you know which allele is dominant you can predict the phenotype of offspring
- Dominant can be homo or hetero for the allele
Consanguinity – where more or less distant cousins produce offsprings – can bring together recessive
disease alleles –
02/10/18
- Heritability: the proportion of the variation in a population that is attributable to genetic
difference.
- Formula
- Can be calculated by comparing the variance of phenotype, in monozygotic vs dizygotic twins
- Meiosis – allows genetic variation. Prophase 1 of meiosis crossing over recombination happens.
Crossing over and recombination happens.
- Phenotype can also disease status, eg: diabetes and subject to migraines.
- A phenotypic train is a single observed parameter – can be inherited, environmental or a
combination.
Mendel
- Pea – demonstrating dominant inheritance of red flowers. – so which ones dominant and which
recessive
Mendelian train
- Simple phenotype classes
- Additive trains – heterozygotes have an intermediate phenotype
- Dominant – two not required.
- Some part of gene encodes for an RNA transcripts – can have its own biological activity eg: rRNA
and tRNA – or can be mRNA which encodes for a protein.
- The common allele is major and the less common allele is minor.
- The major allele is often referred to as wildtype.
- Locus = location of allele on a chromosome.
Inheritance can be 3 type
1) Recessive – 1/4
2) Dominant – 1/2
3) Sex – linked. – usually only males affected, and it can skip a generation.
Consequences of inheritance
- We can predict the possible genotype of offspring
- If you know which allele is dominant you can predict the phenotype of offspring
- Dominant can be homo or hetero for the allele
Consanguinity – where more or less distant cousins produce offsprings – can bring together recessive
disease alleles –
