Beginnings of Molecular Biology

DNA entered public eye with the ____

O.J. Simpson Trial (1995)

What year was Dolly the sheep cloned?

1997

When was the human genome sequenced?

2001

Now DNA is used “______”

Colloquially

In Vivo means

in a living organism

In Vitro means

In a test tube

Study of _______ is key in genetics and molecular biology research

mutations

Major breakthroughs follow ____ breakthroughs

technological

An ______ framework guides all biological research

evolutionary

Heredity:

Transmission of characteristics from parent to offspring

Gregor Mendel gave us:

The law of segregation, The law of independent assortment, The law of dominance

Law of Segregation:

During the formation of gametes, the paired hereditary determinants separate in such a way that each gamete is equally likely to contain either member of the pair

Law of Independent Assortment:

Segregation of the members of any pair of hereditary determinants is independent of the segregation of other pairs in the formation of gametes.

The Law of Independent Assortment assumes that:

genes lie on different chromosomes

Law of Dominance:

For each physical trait, one member of any pair of hereditary determinants is dominant so that the physical trait that it specifies appears in a 3:1 ratio

According to the Law of Dominance alternative form of gene is ______

recessive

Incomplete Dominance:

A form of intermediate inheritance in which one allele for a specific trait is not completely dominant over the other allele

Incomplete Dominance results in a

combined phenotype

What is an example of incomplete dominance?

White and Red flower producing a pink flower

Chromosomal Theory of Inheritance:

A unifying theory stating that inheritance patterns can be explained by assuming the genes are located in specific sites on chromosomes

Boveri and Sutton understood that:

the position of the gene plays a huge role in segregation

Frederick Griffith showed that DNA is the _____

transforming principle

Frederick Griffith’s experiment used an _____ approach

in vivo

Frederick Griffith studied what bacteria and what animal

Streptococcus pneumoniae

Mice

Streptococcus pneumoniae haș two variants which are:

rough harmless colonies

smooth pathogenic colonies

Avery, MacLeod and McCarty used an _____ model with purified DNA

in vitro

Beadle & Tatum linked mutations to _______

metabolism

What did Beadle and Tatum work with?

Neurospora crassa

Beadle and Tatum selected auxotrophic mutants that cannot grow without ______

niacin

One gene - one enzyme is now known as:

one gene - one polypeptide

Hershey and Chase used :

bacteriophage T2

Hershey and Chase knew that bacteriophage T2:

infected and killed E. Coli

Had a protein coat

Contained DNA

What new technology did Hershey and Chase use to separate phage?

Blender

According to the Hershey and Chase experiment, infected bacteria contained

32P

According to the Hershey and Chase experiment, infected bacteria had no

35S

Hershey and Chase’s experiment led to the belief that ____ is heritable

DNA

Replication:

process of making an exact copy of DNA from the original DNA

Transcription:

process of DNA being copied to generate single-stranded RNA identical in sequence to one strand of the double-stranded DNA

Translation:

process of RNA sequence being converted into amino acid sequence of a protein

Reverse Transcription:

process of a single-stranded DNA copy being generated from single-stranded RNA

DNA → DNA

Replication

DNA → RNA

Transcription

RNA (mRNA) → Proteins

Translation

RNA → DNA

Reverse Transcription

Darwin:

concluded that evolution occurs when heritable variation leads to differential success in reproduction

All life evolved from the organism ____

LUCA

Advantageous Changes:

passed on to offspring by positive selection

Deleterious Changes:

tend to disappear by negative selection

Neutral Changes:

may be fixed or disappear in a population over time

Positive Selection of adaptive mutations:

not dominant mode of selection

Negative selection:

dominant and eliminates deleterious mutations while allowing random fixation of nearly neutral mutations

Most of evolution is due to _____

drift