Genetics

Question 1

Father of modern genetics, inheritance patterns through garden peas looking for characteristics (colour, seed shape etc.). Discovered factors of inheritance (alleles), dominant and recessive traits.

Answer 1

Gregor mendel

Question 2

found non-protein substance from nuclei of white blood cells from pus bandages, called nuclein (nucleic acid), evidence that proteins aren’t hereditary material

Answer 2

Friedrich miescher

Question 3

isolated dna and rna based on diff types of sugars (deoxyribose and ribose), showed that they’re made up of individual units (nucleotides) which have a sugar, phosphate, and nitrogenous base. Also said that nucleotide units repeat which means dna is too simple to be genetic material

Answer 3

phoebus levene

Question 4

trying to develop a vaccine for pneumonia. used mice and virulent and non-virulent pneumonococcus. Saw that when heat treated virulent and non-virulent mixed, mice still died. Discovered transformation - bacteria picking up DNA from environment.

Answer 4

frederick griffith

Question 5

experimented using unicellular green algae (acetabularia). Removed either the foot or cap from different algae and they were able to regenerate if it contained a foot. He hypothesized that the hereditary information is stored in the nucleus.

Answer 5

joachim hammerling

Question 6

worked with maclyn mccarty and colin macleod. described the transforming principle through further experimentation with griffiths work. Demonstrated DNA was transforming principle and further proved DNA as genetic material

Answer 6

oswald avery

Question 7

used radioactivity labeled viruses to infect bacterial cells. to determine if protein or DNA was responsible for infecting bacterial cells and producing new viruses. Viral DNA had phosphorus, and protein had radioactive sulfur. Found infected cells contained radioactive phosphorus (DNA), proving DNA is hereditary material, being accepted by the scientific community.

Answer 7

alfred hershey & martha chase

Question 8

experimented with viruses to determine if protein/RNA is responsible for viral replication. Isolated tobacco mosaic virus and the holmes ribgrass virus which contain protein and 1 strand of RNA. Made hybrid with RNA from HRV and protein from TMV. Infected tobacco plant and showed characteristics of HRV. Found evidence that RNA is the hereditary material that RNA is hereditary and in nucleic core.

Answer 8

Heine Fraenkel-Conrat

Question 9

worked on organisms and analyzed DNA compositions. found that DNA compositions are species specific, differ in relative amts from one species to another. A = T, C = G. A+G = T+C

Answer 9

erwin chargaff

Question 10

kings college london, worked on x-ray crystallography, looked at DNA. produced a x-ray diffraction pattern of DNA that suggested a helical shape, position groups of atoms, long and thin, uniform diameter of 2nm, dna coils every 3.4 nm

Answer 10

rosalind franklin + maurice wilkins

Question 11

deduced the structure of DNA using chargaffs, wilkins and FRANKLINS work. Built a model of a double helix, based on uniform diameter, base pairing, hydrogen bonds, were given nobel prize

Answer 11

james watson and francis crick

Question 12

double stranded packed into super coiled structure due to positive charged proteins and negative charged DNA

Answer 12

prokaryote dna

Question 13

supercoiled DNA stored in

Answer 13

nucleoid region

Question 14

1.2 mm long, can fit into a bacterium that is 0.001 mm long

Answer 14

e. coli chromosome

Question 15

DNA twists into a double helix due to hydrogen bonding between the two strands, 2nm wide

Answer 15

step 1

Question 16

dna (-) wraps tightly around histone proteins (+) in order to create nucleosomes

Answer 16

step 2

Question 17

200 base pairs of DNA wrapped twice around a cluster of 8 histone proteins, then passed through a h1 protein to hold the shape, 11nm wide

Answer 17

nucleosomes

Question 18

DNA between nucleosomes bind to the H1 histone proteins creating tightly packed chromatin also called a solenoidal fibre, 30nm wide

Answer 18

step 3

Question 19

protein structure condenses into a chromosome, 1400 nm wide

Answer 19

step 4

Question 20

pentose sugar, phosphate, organic base containing nitrogen

Answer 20

nucleotides

Question 21

bond between sugar & phosphate

Answer 21

phosphodiester bond

Question 22

bond between sugar and base

Answer 22

n-glycosidic bond

Question 23

width of DNA

Answer 23

2nm

Question 24

distance between each base pair

Answer 24

3.4nm

Question 25

phosphate bridges, hydrogen bonding, hydrophobic interactions

Answer 25

3 forces of dna stability

Question 26

depends on hydration level, sequence type, amount of supercoiling

Answer 26

dna conformation

Question 27

a - dehydrated, b- naturally found in living organisms

Answer 27

conformations in organisms

Question 28

replication = 2 new daughter strands that for a new double helix and the two original templates reform into original parent DNA molecule (WILL ALWAYS HAVE ORIGINAL PARENT)

Answer 28

conservative theory

Question 29

watson & crick, daughter DNA is made up of one parent and one daughter strand, identical helices are formed

Answer 29

semi conservative theory

Question 30

parent strands are broken up into fragments, new daughter strands are made up of an assortment of parental and new DNA

Answer 30

dispersive theory

Question 31

e. coli cells grown in a heavy 15N medium, then transferred into a normal 14N medium and allowed to divide, 14N was incorporated into the new strands of DNA (first replication) Cells then allowed to divide again in 14N for more replications. Centrifuged DNA and cesium chloride added to create density gradient. More 14N as time goes on, less hybrid N. Proved semi conservative theory.

Answer 31

meselson and stahl experiment