UNLV BIOL 251 2.1 & 2.2 Regner

Whose work was rediscovered in 1900?

Whose work was rediscovered in 1900?

Gregory Mendel's work

What did biologists begin genetic experiments on?

fly, rabbit, guinea pig, corn, tobacco

What was observed during mitosis and meiosis?

chromosomes; however it was unclear how genes and alleles were connected

genotype --> phenotype...

was a mystery

What was found in the nucleus in 1868?

DNA

What was the fibrous called?

nuclein

Two types of nucleic acids

ribonucleic acid (RNA)

deoxyribonucleic acid (DNA)

RNA contains

uracil and ribose sugar

DNA contans

thymine and deoxyribose sugar

DNA and RNA were present in the ____, had an ____ function, and had no connection btwn ____ acids and ____

nucleus; unknown; nucleic; genetics

What are drosophila?

fruit flies

T.H Morgan's group showed that

genes were carried on chromosomes

Which chromosome has the eye color gene?

X chromosome

Protein(s) complex has ____ amino acids

20

Protein(s) assumed to be _____ material

genetic

DNA was considered

unimportant and uninteresting

scientific name for ear infection

Griffith Streptococcus pneumonia

Types of ear infections

pneumonia, bacteremia, meningitis

do smooth strains produce virulent or avirulent capsules?

virulent

do rough strains produce virulent or avirulent capsules?

avirulent

What was the result when mice were injected with live cells of harmless (R) strain?

Mice live; no live R cells (R cells avirulent) in blood

What was the result with live cells of killer (S) strain?

mice got unalived; live S cells in blood

What was the result when mice were injected with heat-killed S cells?

mice live; no live S cells in blood

What was the result when mice were injected with live R cells + heat-killed S cells

mice unalive; live S & R cells in blood

What did Griffith conclude from this mice experiment?

Griffith concluded that something from the heat-killed S cells transformed the live R cells

What was the debate among scientists about the mice experiment?

debated about what molecule changed the R and S phenotypes

What was the standard assumption about the Transforming Principle?

proteins were responsible for unaliving the mice

What did scientists use that bind specifically to DNA?

dyes

DNA doubles during what phase of the eukaryotic cell cycle?

"S" phase

Symbol for diploid

2n

Symbol for haploid

n

Diploid and haploid describes the number of ____ and the amount of ____

chromosomes; DNA

After meiosis, games have ____ the amount of DNA

half

What is the Transforming Principle?

DNA, RNA, protein

What are the degradative enzymes?

RNase, Protease, DNase

Diagram of evaluating for the presence of cells

What does RNase and Protease contain?

the both contain Virulent S strain and R strain bacteria

What does DNase contain?

R strain bacteria only

What did the Transforming Principle conclude?

R cells were transformed by DNA from heat-killed S cells

Previous Exam Question:

What happened when Fred Griffith mixed heat-killed smooth (S) and live rough (R) strains of Streptococcus pneumoniae?

A. mRNA from the heat-killed S cells were translated into lethal proteins by mice cells; inoculated mice died

B. Heat-killed S cells were revived by the R cells; inoculated mice died

C. Some R cells absorbed the DNA from the heat-killed S cells; inoculated mice died

D. There was no change as compared with the control; all survived

E. Capsule from the heat-killed S cells induced a strong mouse immune response; all mice survived

Some R cells absorbed the DNA from the heat-killed cells; inoculated mice died

Most scientists accepted that genes were composed of what?

genes were composed of DNA

What two nitrogenous bases are purines?

adenine and guanine

What two nitrogenous bases are pyrimidines?

thymine and cytocine

Chargaff's Rule

distinguishing between which two nitrogenous bases were either purines or pyrimidines

What did Rosalind Franklin analyze at King's College?

analyzed DNA with X-ray crystallography

Franklin's results

Helical molecule

Turn every 3.4 nm

Diameter of 2.0 nm

X-ray crystallography diagram

Watson & Crick determined what with DNA?

DNA was a double helix without performing any independent experiments

What data did Watson & Crick use to build models of DNA helix?

alpha helix, width & no. bases per turn, purine = pyrimidines

How did knowing 3D structure of DNA help biologists?

understand DNA replication and transcription

How did purine and purine fit together?

wide fit

How did pyrimidine and pyrimidine fit together?

narrow fit

What were purine and pyrimidine consistent with?

consistent with X-ray diffraction data

How many rings did pyrimidines have?

1-ring

How many rings do purines have?

2-rings

DNA is ____ chains of nucleotides

2 chains

Structure of DNA

Pentose sugar, phosphate group, base

How is DNA synthesized?

connecting the sugars of one nucleotide to the phosphate of the next

How do the sugars connect when DNA is being synthesized?

connects via phosphodiester link/bond

Is Uracil a purine or pyrimidine

pyrimidine

Does DNA contain thymine or uracil?

thymine

Does RNA contain thymine or uracil?

uracil

What bonds are used to pair nitrogenous bases?

H bonds

Which nitrogenous base pairs with thymine?

adenine

Which nitrogenous base pairs with cytosine?

guanine

What are antiparallel strands?

two strands of DNA that run in opposite directions

5' to 3'

3' to 5'

Who won the Nobel Prize in Physiology of Medicine in 1962?

Francis Crick, James Watson, Maurice Wilkins

What year did Rosalind Franklin die?

1958

Which antiparallel are DNA sequences always written?

5' to 3'

What did Hershey and Chase discover?

Bacteriophage T2

What was the function of Bacteriophage T2?

Infects E. coli

What were the two groups of phage?

protein and DNA

How was protein labeled in Bacteriophage T2?

labeled with (superscript) 35S

How was DNA labeled in Bacteriophage T2?

labeled with (superscript) 32P

What did the Henry Chase experiment conduct?

to see which part of the phage (DNA or protein) serves as the genetic material and is transmitted to phage progeny?

What was the result of the Henry Chase experiment?

DNA is genetic material in bacteriophages

What was determined in the life cycle of the T2 bacteriophage?

DNA is the molecule of inheritance. Bacteriophage was put into the E.coli, the virus spread within the E. coli, then virus busted out of E. Coli.

Paradigm Shift (merriam webster)

An important change that happens when the usual way of thinking about or doing something is replaced by a new and different way

Paradigm shift (Cambridge Dictionary)

A time when the usual and accepted way of dong or thinking about something changes completely

What was the role of bacterial cells in the Henry Chase Experiment?

role = pellet

What was the role of the phage in the Henry Chase Experiment?

role = supernatant

100s of thousands of ____ are available at the Joint Genome Institution

genomes

Define Genome

the entre set of DNA found in a cell

What is inside a genome?

chromosomes, mitochondria, chloroplasts, prokaryotic extrachromosomal elements

What is within prokaryotic extrachromosomal elements

plasmids, transposons, integrons, borgs

How many bacterial and archaeal genomes have been sequenced?

Have these 200k microbes been grown in the lab?

no

What percentage of all prokaryotic genomes have been sequenced?

2.1%

How many bp & genes does E. coli have?

E. coli has 4,641,652 bp and 4419 genes

There's a lot of ____ in the prokaryotic world

diversity

Prokaryotic genome size varies tremendously

490,000 bp (smallest) - 9,105,828 bp (largest)

# of genes varies too

480 (smallest) - 9600 (largest)

What do smaller prokaryotic genomes associate?

obligate symbionts, near-obligate and obligate parasites have smaller genomes

Nanoarchaeum lives within or ____ to Ignicoccus, another archaeon

adjacent

How many bp and genes do Nanoarchaeum have?

Nanoarchaeum has 491000 bp and 536 genes

How many bp and genes do Ignicoccus have?

Ignicoccus has 1297583 bp and 1434 genes

Chlamydia trachomatis (chlamydia) and Treponema pallidum (syphilis): cannot ____ without a host in nature

survive

bp and gene of Chlamydia

Chlamydia has 1,042,519 bp and 902 genes

bp and gene of Treponema (syphilis)

Syphilis has 1,138,011 bp and 1082 genes

Obligate symbionts, near-obligate and obligate parasites are missing genes and are dependent upon host for common components:

lipids, amino acids, nucleotides, vitamins, enzymes for cell wall synthesis and citric acid cycle