Chapter 2: Mendelian Inheritance and Probability Flashcards
pangenesis
Hippocrates suggestion that “seeds” are produced by all parts of the body, which are then collected and transmitted to the offspring at the time of conception, causing certain traits of the offspring to resemble those of the parents. (400BCE)
What is Hippocrates concept of inheritance called?
pangenesis
blending inheritance
the view that the factors that dictate hereditary traits can blend together from generation to generation. Refuted by Mendel.
Who performed the first systematic study of genetic crosses?
Kölreuter, in experiments with tobacco from 1761 to 1766, concluded that both parents make equal genetic contributions to their offspring, consistent with blending inheritance: the factors that dictate hereditary traits can blend together from generation to generation. Refuted by Mendel.
What did Kölreuter conclude from his experiments?
Kölreuter, in experiments with tobacco from 1761 to 1766, concluded that both parents make equal genetic contributions to their offspring, consistent with blending inheritance: the factors that dictate hereditary traits can blend together from generation to generation. Refuted by Mendel.
Gregor Johann Mendel
1822-1884: Austrian monk botanist who performed crosses on peas in 1856, considered the father of genetics
hybridisation experiment
two distinct individuals with different characteristics are mated (crossed), to each other, the offspring are referred to as hybrids.
cross
mating two distinct individuals with different characteristics
hybrids
the offspring of a cross (a mating between two distinct individuals with different characteristics)
self-fertilisation
pollen and egg are derived from the same plant
cross-fertilisation
pollen and egg are derived from two different plants
character
one of the general characteristics of an organism, traits (or variants) describe specific properties of a character
trait
traits (or variants) describe specific properties of a character (one of the general characteristics of an organism)
variant
variants (or traits) describe specific properties of a character (one of the general characteristics of an organism)
strain
a strain (or true-breeding line) produces a trait (or traits) that do not vary in appearance from generation to generation, it is homozygous for that trait
true-breeding line
a true-breeding line (or strain) produces a trait (or traits) that do not vary in appearance from generation to generation, it is homozygous for that trait
monohybrid cross
A monohybrid cross is a mating between individuals who have different alleles at one genetic locus of interest. The character(s) being studied in a monohybrid cross are governed by two alleles for a single locus.
To carry out such a cross, each parent is chosen to be homozygous or true breeding for a given trait (locus). When a cross satisfies the conditions for a monohybrid cross, it is usually detected by a characteristic distribution of second-generation (F2) offspring that is sometimes called the monohybrid ratio.
single-factor cross
A monohybrid cross (or single factor cross) is a mating between individuals who have different alleles at one genetic locus of interest. The character(s) being studied in a monohybrid cross are governed by two alleles for a single locus.
To carry out such a cross, each parent is chosen to be homozygous or true breeding for a given trait (locus). When a cross satisfies the conditions for a monohybrid cross, it is usually detected by a characteristic distribution of second-generation (F2) offspring that is sometimes called the monohybrid ratio.
empirical approach
Empirical research is a way of gaining knowledge by means of direct and indirect observation or experience. Empirical evidence (the record of one’s direct observations or experiences) can be analyzed quantitatively or qualitatively. Through quantifying the evidence or making sense of it in qualitative form, a researcher can answer empirical questions, which should be clearly defined and answerable with the evidence collected (usually called data).
P generation
The parental generation, the initial generation that is crossed
F1 generation
The first filial generation, the initial offspring of a cross
F2 generation
The second filial generation, the offspring of the F1 generation
Particulate theory of inheritance
The genes that govern traits are inherited as discrete units that remain unchanged as they are passed from parent offspring, Mendell called them factors, we now call them genes
Gene
A unit of heredity that may influence the outcome of an organism’s traits
