Studied by 4 people
What is genetics?
the stud of heredity and variation in cells
What are genes?
the functional unit of heredity and variation
What are alleles?
different versions of the same genes
What is your genotype made up of?
an individual’s complete set of alleles
What is genotype?
allele combinations you have
What is phenotype?
visible/observable traits
What is a genome?
genetic material of an organism
entire DNA sequence of an organism
Where are genes found? What are they part of
found on chromosomes
parts of then genomes that encode for RNA and protein
What is coding and noncoding RNA
coding: mRNA
noncoding: tRNA
What is gene expression?
‘turning on’ a gene to produce RNA and protein
essentially, making RNA
Which one is first, transcription or translation?
transcription
What is protein expression?
the type and abundance of protein in a cell
What do proteins determine?
they determine the phenotype of the cell because they control every reaction in the cell (i.e enzymes)
What do enzymes (proteins) do?
catalyzing the synthesis and transformation of all biomolecules
What do structural proteins do?
they maintain the cell shape
What are signalling proteins?
hormones and receptors
What makes individuals different from each other? (why do people have different phenotypes)Why do relatives look alike?
different alleles (a slight variation in gene sequence results in changes in the amino acid sequence of proteins)
differential regulation of gene and protein expression (more mRNA, means more proteins)
relatives possess common alleles and gene regulation, causing them to look alike
What is the smooth strain (S) of pneumonia?
a bacterium that has a capsule that protects it from the immune system
it is allows infection
What is the rough strain (R) of pneumonia?
bacterium that does not have the polysaccharides capsule
can’t evade immune system, non-virulent
What was Griffith’s experiment?
injected mice with the S strain (mice died) and injected mice with R strain (mice survived)
heat killed the S strain and injected mice with it (they survived)
injected mice with heat killed S strain and not heat killed R strain (mice died)
What did Griffith conclude?
the transforming principle
concluded that something from the hear killed S strain bacteria was passed to the R bacteria that transformed them into virulent bacteria
the transformation was permanent and heritable
What was Avery, MacLeod & McCarthy’s hypothesis?
transforming principle could be protein, DNA or RNA—which one is it?
What was Avery, MacLeod & McCarthy’s experimental approach?
eliminate each type of molecule and see whether transformation of R cells into S virulent form still occurs
What was Avery, MacLeod & McCarthy’s conclusion?
if the type of molecule is absent and transformation is gone, then this molecule is the transforming principle
What was Avery, MacLeod & McCarthy’s experiment
they added the cytoplasm of heat killed S cells and added them into separate tubes
in the first tube, they added RNAse (destroys RNA) and then added R cells. the however the mouse still died, so transformation still occurred
in the second test tube they added protease (destroys protein) and then added R cells. the however the mouse still died, so transformation still occurred
in the third tube, they added DNAse (destroys DNA) and then added R cells. the mouse survived therefore transformation was unable to occur. so DNA is transforming principle
Can viruses replicate without hosts?
no
What are the steps of viral replication?
virus attaches to the outside of the host cell
virus injects nucleic acid into the host
virus hijacks cell machinery to replicate its own components
virus is ejected from cell to infect other hosts
What is the lytic cycle?
the final step in viral replication that bursts open and kills host cells
massive reproduction of viruses
What are the steps of the lytic cycle?
phage infects a cell
the phage remains SEPARATE from the host DNA
the phage DNA replicates, new phage particles are assembled, phage proteins made
the cell burst open, releasing the phages
What are the steps if the Lysogenic cycle?
phage infects cell
phage DNA becomes integrated into host genome
the cell divides and prophage DNA is passed onto daughter cells
When can lysogeny switch to the lytic cycle?
under stressful conditions!
the phage DNA is excised from the bacterial chromosome and enters the lytic cycle
What was the Hershey and Chase experiment?
they had to answer whether bacteriophages inject DNA or protein
they labelled bacteriophage DNA and proteins with radioactive isotopes
32P labelled DNA and 35S labelled Proteins
They allowed infection of E.coli with the radioactive bacteriophage and separated the attached bacteriophage with a blender
they saw that there were no 35S in E.coli cells in the progeny bacteriophage (not radioactive). There was 35S in the detached bacteriophage
they say that 32p was in E.Coli cells and no 32P was found in the detached bacteriophage. 32P in progeny bacteriophage
Why did Hershey & chase use bacteriophages?
b/c they can’t reproduce themselves
they have to inject their heritable molecule into bacteria cell, and force the bacteria to make new viruses
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Flashcard (32)