Quiz 1 Molecular Genetics

Molecular biology

Study of gene structure at the molecular level

Garden pea is a good model organism why?

Lots of contrasting traits & large flowers

Monohybrid

Parents differ in 1 trait

Who proposed particulate mechanism of inheritance

Mendel

Punnett square

Modern day way of explaining how genes come together in a cross

Law of segregation

= and independent segregation of alleles during gamete formation

Sister chromatids

Replicated chromosomes

Homologous chromosomes

Chromosome pairs

Mitosis

Asexual reproduction & growth

Meiosis

Num of chromosomes cut in half

Locus

Physical location of a gene on a chromosome

Who proposed the chromosomal theory of inheritance

Walter Sutton

Who proved chromosomal theory of inheritance

Thomas Hunt Morgan

What was Thomas H Morgan’s experiment

Bred white eyed males and red eyed females, proved a genetic trait was linked to a particular chromosome

Crossing over

Alleles can trade places from one homologous chromosome to another

Map unit

Relevant distance or gene mapping

Griffith’s Experiments

S. Pneumoniae

Smooth bacteria (s) has a capsule + kills, rough (R) did not

R takes up genetic material from S and becomes fatal

Avery, MacLeod, and McCarty experiment

Continued Griffith’s work

When DNA removed, R bacteria did not become fatal

Hershey and Chase Experiment

T2 Virus infecting E. coli

DNA inserted into bacteria

What was DNA labeled with in Hershey and Chase’s experiment

32P

What were proteins labeled with in Hershey and Chase’s experiment

32S

Beagle and Tatum Experiment

Neurospora crassa (mold)

Created auxotrophs

Proposed one gene one enzyme hyp (now one gene one polypeptide)

Auxotrophs

Mutant strains that require an extra nutrient in their media to grow

Wild type does not need extra nutrient

Crick’s central dogma

DNA → RNA → Protein

mRNA

Similar composition to chromosomal DNA

Carries info from DNA → ribosome

Transcription

synth RNA from the template strand

tRNA

Crick’s adaptor molecule that links RNA and amino acids

Translation

Process of producing a protein product from a mRNA molecule

2 nucleic acids

RNA and DNA

parts of a nucleotide

5C sugar, phosphate group, 1 of 4 bases

2 types of pentoses

2-deoxyribose + ribose

How are bases linked to sugars

Glycosidic bonds

How are nucleotides linked together to form nucleic acids

Phosphodiester bonds

What is on the 5’ end of a nucleic acid strand

Phosphate

What is on the 3’ end of a nucleic acid strand

Hydroxyl (OH)

The backbone of a nucleic acid is made up of what

Sugars and phosphate parts

The backbone is hydrophilic or hydrophobic?

Hydrophilic

The bases are hydrophilic or hydrophobic?

Hydrophobic

What are Chargaff’s rules?

A-T + G-C

Watson and Crick

Proposed a right-handed double helix containing two entwined strands of DNA

What holds the DNA strands together

The bases H-bonds

How many base pairs (bp) per turn

10

DNA strands are

Complementary and anti parallel

What are the major and minor grooves of DNA

Places where proteins interact

RNA

Forms lots of secondary structures and has a large structural variety

Double Stranded RNA

Antiparallel

Right handed helix, irregular bp, single stranded regions

Alpha helix

Ribonucleo-proteins

RNA that folds into 3D structures in the presence of proteins

What base spontaneously delaminates to form uracil?

Cytosine

Ribozyme

Catalytic RNA

Natural selection depends on what two things?

Population variance and competition

Genome

Complete copy of genetic info of an oraganism

Recombinant DNA

Method for separation of a particular gene/segment from the genome and increasing its number

Restriction enzymes

Cut DNA in a predictable way at a precise location

Defense mechanism against invading DNA

Recognition site

Place where a restriction enzyme cuts

Palindromes 4, 6, or 8 bp long

Sticky end

Jagged end of either 3’ or 5’ + overhang 2-4 bases long

Blunt end

Cut straight across from each other

Cloning vector

Small DNA molecule capable for replication

Types of cloning vectors

Plasmids and phages

Why is the same restriction enzyme used for digestion of the vector and the inserted fragment

Complimentary sticky ends

Ligase is used to do what in creating a recombinant DNA plasmid vector

Seal the phosphodiester backbone

What is a BAC

Bacterial artificial chromosome

What is a YAC

Yeast artificial chromosome

Plasmid

Circular DNA molecule that replicates separately from the host chromosome

4 traits of a good plasmid vector

Origin of replication, selectable markers, unique restriction site for many enzymes, scoreable phenotype

How are small plasmids introduced into bacterial cells

Transformation

Electroporation

Cells are shocked to loosen the membrane

LacZ gene

Codes for beta-galactosidase which creates a blue dye

LacZ system

Tests to see if cloned DNA inserted by disrupting the gene and causing the colonies to grow white instead of blue

BACs and YACs

Used to clone and maintain large pieces of DNA

DNA library

Collection of DNA fragments/clones

Genomic library

Represents most fragments of an organisms genome

Genomic equivalent

Num of clones in a perfect library

cDNA library

Collection of fragments actually expressed/transcribed

Reflects mRNA

PCR

Testing that relies on DNA polymerase and primers to replicate a segment of DNA in a test tube

At what temp in PCR is DNA denatured

90-95

At what temp in PCR do primers anneal

40-60

At what temp does DNA synth occur in PCR testing

72

RT-PCR and qPCR

Used to measure / quantify mRNA levels

Things needed to do Sanger sequencing

Primer, DNA polymerase, Dideoxy nucleotides (ddNTP), a labeled primer/nucleotide

DNA microarray

Rapidly screens expression of a huge number of genes