1. Mendel - Before & Ideas Flashcards
Difference between truth and consensus
Truth - timeless
Consensus - changes with time
- think about consensus before and after discovery
Consensus before Mendel
traits/inheritance blended
Mendel’s purpose
- To find what controls inheritance
- To find the underlying principles of inheritance supported by statistics
- To be able to predict inheritance
Mendel’s phenotypes
only had 2 variants/alternatives
• TRUE BREEDING
True breeding
parents with a particular phenotype produce offspring with the same phenotype
Mendel may not have considered
heterozygotes
Tt - Mendel found
NO BLENDING
3 tall
1 small
- 1 pure breeding (TT)
- 2 hybrid (Tt)
Traits are…
preserved
• molecules inherited
• not liquid
Height would…
range
• no true inheritance
• answers biased (by question)
No blending of traits, got…
PARTICULATE INHERITANCE
Particular inheritance
characteristics can be passed from generation to generation through “discrete particles”
Mendel’s first law said that
inheritance is particulate
then asked how they’re related (or independent)
- do they influence each other, can they be mathematically related (predict 1 from another)
- paired phenotypes to find answer
If phenotypes (Tt and Yy) affected each other completely, you would find
3:1
3 TY:1 ty
Mendel found (Tt and Yy)
were INDEPENDENT
9:3:3:1
thought particles `
Mendel’s first law
SEGREGATATION
(Law of Purity of Gametes)
• the pair of alleles separate when making gametes (meiosis)
• separation of homologous chromosomes during meiosis leads to each cell (gamete) with 1 allele for the trait
