3-1 The Mechanisms of Inheritance Flashcards
What was the 19th century view on inheritance
blending of traits
What is artificial selection
people select for desirable traits in plants or animals rather than nature
Who was mendels question
how do new varieties of plants or breeds come about
What was Mendel’s hypothesis
- Each plant contains 2 factors for a trait
- When crossing 2 plants they randomly passed on one factor or the other to each offspring
- When crossing 2 pure strain plants that differ in a trait, each offspring will receive a dominant and recessive factor for that trait: all offspring will be hybrids for that trait
-And when crossing 2 hybrids, 5050 chance each parent’s contribution will be one factor or the other which means 4 possible combinations in their offspring
What were alleles previously called
factors
What does homozygous dominant mean
2 dominant form of allele
What does heterozygous mean
having 1 dom and 1 recessive
What does homozygous recessive mean
having 2 of the recessive form of an allele
What does monohybrid cross mean
crossing 2 plants that differ in only one characteristic
What does dihybrid crossing mean
crosses where the parent plants differed in 2 different characteristics
What are Mendel’s Principles
- Principle of segregation
- Principle of Dominance and Recessiveness
- Principle of independent assortment
What is the principle of segregation
- offspring inherit one discrete factor for a trait from each parent
- These factors maintain unique integrity from gen to gen
What is principle of dominance and recessiveness
Some expressions of a specific trait were dominant over others
What is the principle of independent assortment
Different traits were not inherited together as packages, they passed from gen to gen as independent units (Not exactly true)
What does monogenic mean
involving or controlled by a single gene.
