Mendel’s Work (genetic) Flashcards
What is genetic
Genetic is a branch of biology that studies how biological traits are inherited
Involves sexual reproduction
Originally what was genetics, what was the past understanding of this field
Long know that mating healthy vigorous animals would produce superior offspring ( better quality of parent passed on better characteristics to offsprings)
- no scientific basis or understanding of mechanisms
- lot of misconception about what could be passed on or not
What can be inherited, give examples
Only biological characteristics (heritable traits)
Example:
- height
- skin, hair and eye colour
- all developmental and control processes run by enzymes
What cannot be inherited
Acquired characteristic
Example:
- muscular development
- knowledge and learned skills
Give the grand lines of Mendel’s work
Mainly worked on pea plants
Choose characteristic easy to observe and quantify ( flower colour and height )
Used mathematical analysis to gave rise to a general principle known as Mendel laws
What is the scientific name of garden peas and why were they a suitable choice ?
Pisum sativum
Pea hybrids could be produced by crossing different varieties
- many pea varieties were available for Mendel to analyze
- the grow easily and in a short period of time
They can both cross fertilize and self fertilize
What were the flaws in mendel’s work
He had no idea of the existence of meiosis, chromosomes and genes
However it still explained how meiotic process could work to produce the result he obtained with no knowledge of it
What are 2 generalizations obtains through mendel’s work
The principle of segregation
- describes how pairs of gene variants are separated into reproductive cells
The principle of indépendant assortment
- describes how different genes independently separate from one another when reproductive cells develop
What is true breeding (pure lines)
any crosses performed will result in offspring with the same phenotype
What were Mendel’s experimental methods
- true breeding
- reciprocal crossing
Cross fertilize true breeding strains having alternate forms of a trait - allow hybrid offspring to self fertilize and count the number of offspring with each form of a trait
What is monohybrid cross ?
A cross to study only 2 variations of a single trait
Example in mendel’s experiments
Cross between a purple flower and a white one
Purple x white
Modern explanation for biological characteristics
It is controlled by genes located on the chromosomes
What are genes, what do they contain
The basic unit of heredity - made up of DNA
Each gene
Contain information needed to make a specific protein ( usually an enzyme )
-enzymes work in an assembly line fashion
Produce substance which ultimately affects the development of an organism
The gene locus (simplified )
Each gene occurs on a specific chromosome and as a specific location on it
Therefore each gene has a predictable location called the gene locus
How many copies of a particular gene exist for each characteristic of an organism?
Two ; one on each member of a homologous pair
