Week 1 Flashcards
Natural Selection
Individuals with certain traits are more likely to survive and reproduce in a given environment
Artificial Selection
Humans choose which will reproduce
ex: carrots, dogs
Domestication Syndrome
Floppy ears, white colour, coat colour variation, prolonged “childlike” behaviour
Gregor Mendel
Monk that studied inheritance by breeding pea plants
Antagonistic Traits
Traits with opposites, only two options
Pre-Mendel Inheritance Theories
- One parent contributes more
- Traits become mixed and changed forever
Mendel’s Law of Segregation
Alleles separate into gametes, and randomly united
Phenotype
Visible characteristic, trait
Genotype
Genetic makeup, based on DNA code
Alleles
Units of inheritance, forms of a single gene
Polymorphic
Several alleles found in a population
Monomorphic
Only one allele normal in a population
Monohybrid
One trait, heterozygous pair, ratio 3:1
Dihybrid
Two traits, heterozygous pair has a ratio of 9:3:3:1
Test Cross
Used to determine the genotype of an organism expressing the dominant phenotype by crossing with the recessive phenotype
Product rule
Independent events occurring at the same time
Sum rule
When determining of “either/or” events, add together
Binomial Theorem
Certain # of successes + failures, use Pascal’s Triangle
Co-dominance
Both alleles are visible in the phenotype (1:2:1)
Incomplete dominance
An intermediate between alleles is present in the phenotype (1:2:1)
Multiple Alleles
More than two alleles for any one gene
- Reciprocal crosses are used to detect the dominance series
Pleiotropy
One gene influences multiple traits
- ex sickle cell syndrome
Epistasis
One gene hides the other gene’s effect
Recessive Epistasis
If an organism has two recessive alleles for a trait, the appearance of the other trait is masked (ratio 9:4:3)
- Labrador retrievers, Bombay bloodtype
