Three foci of genetics-
Transmission of genetic information from- parent to offspring (transmission genetics), over many
generations within a population (evolutionary genetics) and DNA to gene action in/ within cells (molecular
development genetics).
Gregor Mendel-
● Proposed there are two copies of genes controlling a particular characteristic in each of the cells-
somatic cells (cells other than sex cells). However, when plant forms gametes only one gene out
of the pai enters the cell.
● Variants of genes are called alleles.
● One allele is dominant (3:1 :: dominant:recessive) explains there is no blending theory (if tall and
short plant is combined than all plants are medium height)
Central dogma-
Model organisms-
Species used in biological experimentation with presumption that findings from their analysis holds true
for other species, especially closely related ones. Usually are-
● Small, inexpensive, convenient organisms.
● Have short generation time.
● Small genomes is useful, in terms of DNA base pairs. Usually large genomes is because of
repetition of DNA bases between genes.
● Organisms with easy to mate and produce many offsprings.
Tools for genetic analysis-
● Molecules- DNA polymerase (makes copy of single strand from existing sequence, also can label
nucleotides added by polymerase), Nucleases (cut DNA at specific parts/ single nucleotides),
Ligases (joins DNA molecules end to end).
● Clone DNA- making many copies of entire specific gene or a portion. Inserting in host (e.coli)
DNA and using its polymerase to clone.
● Transformations-Inserting foreign DNA into the genomes of many model species creating GMO.
● Hybridising DNA molecules- hydrogen bonds can be denatured by heat and cooled to anneal.
Fluorescent tags can be inserted in this process to reveal the location of the gene.
● DNA sequencing
, Information for making an organism in the nucleotide sequence of the DNA. Can be passed on to
generations by each separated strand serves as a template for producing new molecules.
Fredrick griffth’s discovery of transformation-
a) Transformation- the DNA from heat killed S cells is taken up by R cells to transform into S live
cells that can be recovered.
b) To decide what part of the S heat killed cells is causing the R cells to become virulent, each cell
part was chemically destroyed from S cells to prevent R live cells from using it. Polysaccharides
were suspected as R cells need them to change to S cells. But, only destruction of DNA
prevented R cells becoming virulent.
c) To show that DNA is the transforming agent and genetic material. The DNA parts with virulence
from S dead cells transfer to the R cell’s DNA and counter non-virulence parts.
Transmission of genetic information from- parent to offspring (transmission genetics), over many
generations within a population (evolutionary genetics) and DNA to gene action in/ within cells (molecular
development genetics).
Gregor Mendel-
● Proposed there are two copies of genes controlling a particular characteristic in each of the cells-
somatic cells (cells other than sex cells). However, when plant forms gametes only one gene out
of the pai enters the cell.
● Variants of genes are called alleles.
● One allele is dominant (3:1 :: dominant:recessive) explains there is no blending theory (if tall and
short plant is combined than all plants are medium height)
Central dogma-
Model organisms-
Species used in biological experimentation with presumption that findings from their analysis holds true
for other species, especially closely related ones. Usually are-
● Small, inexpensive, convenient organisms.
● Have short generation time.
● Small genomes is useful, in terms of DNA base pairs. Usually large genomes is because of
repetition of DNA bases between genes.
● Organisms with easy to mate and produce many offsprings.
Tools for genetic analysis-
● Molecules- DNA polymerase (makes copy of single strand from existing sequence, also can label
nucleotides added by polymerase), Nucleases (cut DNA at specific parts/ single nucleotides),
Ligases (joins DNA molecules end to end).
● Clone DNA- making many copies of entire specific gene or a portion. Inserting in host (e.coli)
DNA and using its polymerase to clone.
● Transformations-Inserting foreign DNA into the genomes of many model species creating GMO.
● Hybridising DNA molecules- hydrogen bonds can be denatured by heat and cooled to anneal.
Fluorescent tags can be inserted in this process to reveal the location of the gene.
● DNA sequencing
, Information for making an organism in the nucleotide sequence of the DNA. Can be passed on to
generations by each separated strand serves as a template for producing new molecules.
Fredrick griffth’s discovery of transformation-
a) Transformation- the DNA from heat killed S cells is taken up by R cells to transform into S live
cells that can be recovered.
b) To decide what part of the S heat killed cells is causing the R cells to become virulent, each cell
part was chemically destroyed from S cells to prevent R live cells from using it. Polysaccharides
were suspected as R cells need them to change to S cells. But, only destruction of DNA
prevented R cells becoming virulent.
c) To show that DNA is the transforming agent and genetic material. The DNA parts with virulence
from S dead cells transfer to the R cell’s DNA and counter non-virulence parts.
