Ch. 9 Patterns of Inheritance Flashcards
Genetics
Science of heredity (study of the inheritance of traits)
- founded by Gregor Mendel
Who was Gregor Mendel?
“Father of Genetics”
- experiment with pea plants for seed shape, color (flower/seed), pod shape, flower position, stem length plant mating
- parents pass onto offspring discrete heritable factors that retain individuality generation to generation
Chromosome Theory of Inheritance
Genes are physical units located on chromosome and the behavior of chromosomes during meiosis/fertilization determine inheritance patterns
Mono-hybrid cross
Cross w/ only 1 variable at a time
Allele
Alternative form of a gene
- each trait is determined by 2 alleles (1 from each parent)
Dominant
Allele that rules/dominates over other
- expressed (A)
Recessive
Hidden/masked by dominant allele
- expressed w/ 2 recessive alleles (a)
Genotype
Genetic description a trait based on a pair of alleles (BB)
Phenotype
Physical appearance/description of a trait
Homozygous
Genotype w/ same pair of allele (purebred)
Heterozygous
2 different types of alleles in genotype (hybrid)
Parental Cross
Pure dominant crossed with pure recessive
Principle of Segregation
Pairs of alleles separate during gamete formation
Principle of Independent Assortment
Each pair of alleles separate independently during gamete formation
Dihybrid cross
Genes fro two traits are independent
Probability
Mathematical science that predicts the chance a certain event will occur
Rules of multiplication
The change that two independent events will occur together is the product of their chances occurring separate
Does chance have memory?
No. A change event is not affected by previous events.
Trihybrid Cross
3 traits at the same time
Wild type
The phenotype most commonly found in nature
Self-fertilization
Fusion of sperm and egg that are produced by the same individual organism
Cross fertilization
Fusion of sperm and egg derived from two different individuals