Mendelian Inheritance Notes Flashcards
What is Pangenesis?
A hypothesis proposing that all cells produce tiny particles called ‘gemmules’ which travel through the bloodstream to reproductive organs
Pangenesis was proposed by Hippocrates around 400 B.C.
What does the blending hypothesis of inheritance suggest?
Factors controlling hereditary traits are malleable and can blend together from generation to generation
Who conducted landmark genetic studies on garden peas?
Gregor Mendel conducted landmark genetic studies from 1856 to 1864
What was the title of Mendel’s work published in 1866?
Experiments in Plant Hybridization
What are hybrids in the context of Mendel’s experiments?
The offspring resulting from the breeding of two individuals with different characteristics
Why did Mendel choose garden peas (Pisum sativum) for his experiments?
They existed in several varieties with distinct characteristics and allowed for easy controlled crosses
What are the two types of breeding experiments Mendel conducted?
- Self-fertilization
- Cross-fertilization
What is a true-breeder?
A variety that produces the same trait over several generations
What is the Law of Segregation?
The two copies of a gene segregate from each other during gamete formation, so each gamete carries one copy of a gene
What does genotype refer to?
The specific allelic composition of an individual
What does phenotype refer to?
The observable traits of an individual
What is a Punnett square?
A grid that predicts the outcome of simple genetic crosses
What is the genotypic ratio in a cross between two heterozygous tall plants (Tt)?
1 : 2 : 1 (TT : Tt : tt)
What is the phenotypic ratio in a cross between two heterozygous tall plants (Tt)?
3 : 1 (Tall : Dwarf)
Fill in the blank: An individual with two identical alleles is termed _______.
homozygous
Fill in the blank: An individual with two different alleles is termed _______.
heterozygous
What is the significance of Mendel’s empirical approach in his experiments?
It was used to deduce empirical laws governing hereditary traits
What did Mendel’s results reveal about the blending mechanism of heredity?
The results refuted a blending mechanism; traits do not blend but are inherited as discrete units
Who rediscovered Mendel’s work in 1900?
Hugo de Vries, Carl Correns, and Erich von Tschermak
