At the organismal level Flashcards
Character vs Trait
Character:
Heritable feature that varies among individuals
Trait:
Each variant for a character
Self-fertilization
When pollen lands on carpel and fertilize egg on the same flower
Cross-polinating
- Immature stamens are removed
- Pollen from another plant is dusted onto flower
- Creates offspring of different variety
True-breeding plants
- Plants that self-pollinated over many generations
- Produced only the same variety as the parent plant
- Always passes down a phenotypic trait for many generations
Hybridization
Crossing of 2 true-breeding varieties
Law of segregation
- Heritable factor for white flower is hidden when purple-flower factor is present
- Purple flowers are dominant trait
- White flowers are recessive traits
- Reappearance of white was not diluted and the trait has not disappeared
- 3:1 ration (3 for dominant)
- 2 alleles for a character segregate during gamete formation and end up in different gametes
- Egg or sperm gets only one of the 2 alleles present in somatic cells
Law of independent assortment
- If plant F1 exhibits both dominant characters must look at F2
Each pair of alleles segregates independently of each other pair of allele during gamete formation
- 2 pairs of alleles segregate independently of each other
- Genes packaged into gametes in all possible allelic combinations
- Each gamete has one allele for each gene
Which is dominant and which is recessive?
- White or Purple
- Smooth or wrinkled
- Yellow or green
- D: Purple
R: White - D: Round/smooth
R: Wrinkled - D: Yellow
R: Green
Monohybrid
- Heterozygous for one character followed in a cross
Monohybrid croos
Cross between heterozygotes for one character
Dihybrid
- Individuals heterozygous for 2 characters followed in a cross
Digybrid cross
Cross between F1 dihybrids
Addition Rule
To calculate probaility of monohybrids
Multiplication Rule
To calculate probability of dihybrids
Complete dominance
When phenotype of heterozygote and domninant homozygot are indistinguishable