genetics - bio 2200 shiu exam 1
genetics - ANS-the study of genes/heredity
why do we study genetics? - ANS-the genetic background of an individual affects its
characteristics
gene - ANS-the basic unit of inheritance
alleles - ANS-alternative forms of a gene
wild type (WT) - ANS-the standard/normal form
mutant - ANS-a form different from the wild type
genotype - ANS-genetic makeup of an organism
phenotype - ANS-observable properties of an organism
what does a minus sign mean? - ANS-it is a mutant
eukaryotes - ANS-organisms in which the genetic material is enclosed in a nucleus,
generally has (multiple) linear DNA in its nucleus and (one) circular DNA in their
organelles (mitochondria and chloroplasts), can be multi- and unicellular
Ex: mus musculus (mouse), homo sapiens (human)
prokaryotes - ANS-have no nuclei, generally has (one) circular DNA in its cytoplasm,
almost always unicellular
Ex: escherichia coli (intestinal bacterium)
Griffith's Transformation Experiment - ANS-- streptococcus pneumoniae bacteria in
mice
- showed that genetic material passed from dead bacteria into nearby living ones,
allowing them to change their cell surface (rough-->smooth)
- S strain=infectious, R strain=safe, heat killed S strain=safe, heat killed S strain + R
Strain=infectious
, - R bacteria uptake genetic material from dead S bacteria & are transformed into an
infection strain
Avery's Transformation Experiments - ANS-- lyse dead S cells
- separate cell extract from cell debris
- determine which component of the extract is capable of transforming an R strain into
an S strain
- add SIII to the cell extract (to destroy sugars/polysaccharides)--> transformation
- add protease (to destroy proteins)--> transformation
- add RNase (destroy RNA)--> transformation
- add DNase (destroy DNA) -->no transformation
- conclusion: transforming principle is DNA
Hershy-Chase Bacteriophage Experiments - ANS-- DNA is the genetic material
- bacteriophage T2 bc it only contains DNA and proteins so it has to be one
- T2 DNA labeled w radioactive phosphorus, proteins labeled w radioactive sulfur
- 32P labeled DNA found inside host, 35S labeled protein was found outside the host
- bc the T2 injects genetic material inside the host, DNA must be carrying the genetic
info
DNA vs RNA - ANS-BOTH:
- polymers composed of monomers called nucleotides
- each nucleotide is composed of a pentose sugar, a nitrogenous base, and a
phosphate group
RNA:
- pentose sugar= ribose
- has a hydroxyl group (OH)
DNA:
- pentose sugar= deoxyribose --> remove oxygen
- only has a hydrogen
- written 5' to 3'
nitrogenous bases - ANS-- nitrogen containing bases
- purines (double ring, 9 membered) A and G
- pyrimidines (one ring, 6 membered) T, C, and U (RNA)
nucleotides - ANS-base is attached by a covalent bond btwn the 1' carbon of the
pentose sugar and a nitrogen in the base
genetics - ANS-the study of genes/heredity
why do we study genetics? - ANS-the genetic background of an individual affects its
characteristics
gene - ANS-the basic unit of inheritance
alleles - ANS-alternative forms of a gene
wild type (WT) - ANS-the standard/normal form
mutant - ANS-a form different from the wild type
genotype - ANS-genetic makeup of an organism
phenotype - ANS-observable properties of an organism
what does a minus sign mean? - ANS-it is a mutant
eukaryotes - ANS-organisms in which the genetic material is enclosed in a nucleus,
generally has (multiple) linear DNA in its nucleus and (one) circular DNA in their
organelles (mitochondria and chloroplasts), can be multi- and unicellular
Ex: mus musculus (mouse), homo sapiens (human)
prokaryotes - ANS-have no nuclei, generally has (one) circular DNA in its cytoplasm,
almost always unicellular
Ex: escherichia coli (intestinal bacterium)
Griffith's Transformation Experiment - ANS-- streptococcus pneumoniae bacteria in
mice
- showed that genetic material passed from dead bacteria into nearby living ones,
allowing them to change their cell surface (rough-->smooth)
- S strain=infectious, R strain=safe, heat killed S strain=safe, heat killed S strain + R
Strain=infectious
, - R bacteria uptake genetic material from dead S bacteria & are transformed into an
infection strain
Avery's Transformation Experiments - ANS-- lyse dead S cells
- separate cell extract from cell debris
- determine which component of the extract is capable of transforming an R strain into
an S strain
- add SIII to the cell extract (to destroy sugars/polysaccharides)--> transformation
- add protease (to destroy proteins)--> transformation
- add RNase (destroy RNA)--> transformation
- add DNase (destroy DNA) -->no transformation
- conclusion: transforming principle is DNA
Hershy-Chase Bacteriophage Experiments - ANS-- DNA is the genetic material
- bacteriophage T2 bc it only contains DNA and proteins so it has to be one
- T2 DNA labeled w radioactive phosphorus, proteins labeled w radioactive sulfur
- 32P labeled DNA found inside host, 35S labeled protein was found outside the host
- bc the T2 injects genetic material inside the host, DNA must be carrying the genetic
info
DNA vs RNA - ANS-BOTH:
- polymers composed of monomers called nucleotides
- each nucleotide is composed of a pentose sugar, a nitrogenous base, and a
phosphate group
RNA:
- pentose sugar= ribose
- has a hydroxyl group (OH)
DNA:
- pentose sugar= deoxyribose --> remove oxygen
- only has a hydrogen
- written 5' to 3'
nitrogenous bases - ANS-- nitrogen containing bases
- purines (double ring, 9 membered) A and G
- pyrimidines (one ring, 6 membered) T, C, and U (RNA)
nucleotides - ANS-base is attached by a covalent bond btwn the 1' carbon of the
pentose sugar and a nitrogen in the base
