Lesson 9: DNA

Question 1

where are genes carried and what form are they carried in

Answer 1

genes are carried on chromosomes in the form of DNA

Question 2

how was DNA discovered

Answer 2

it was discovered by Friedrich Miescher in 1869, who isolated a compound found in the nucleus of a cell

Question 3

what was the compound Friedrich found in the nucleus of the cell called

Answer 3

nuclein

Question 4

how long did it take to determine that DNA was responsible for heredity

Answer 4

decades after Friedrich isolated this compound

Question 5

who verified that genetic material was contained in the nucleus?

Answer 5

joachim hammerling verified this in the 1930s
- it was noted that in a single celled algae called Acetabularia, the cell would only regrow if the nucleus was still present

Question 6

what did hammerling determine from his experiment with algae

Answer 6

he determined that the nucleus must contain the genetic material

Question 7

who proved hammerling’s hypothesis? how did they do this

Answer 7

hammerling’s hypothesis was proven in 1952 by Alfred Hershey and Martha Chase
- they did so by showing that viruses only need to inject their DNA into a cell to take over their organelle to produce more virus, which proved that DNA was the hereditary material
- this is because when virus injects DNA, its instructions override the other instruction and instructs the cell to make more virus (genetic material AKA DNA was the hereditary material that gave instructions)

Question 8

what is DNA chemically composed of and who was this discovered by

Answer 8

in the 1920s, Phoebus Levene discovered DNA had 3 main components
- a pentose sugar (5 carbon cyclical sugar)
- a phosphate group with a negative charge
- a nitrogenous base

Question 9

what do the components of DNA come together to form?

Answer 9

a nucleotide, which are building blocks of DNA

Question 10

What is DNA?

Answer 10

deoxyribonucleic acid; its a molecule or a bunch of atoms stuck together which combine to form the shape of a long spiraling ladder- it is a molecular blueprint for a living thing

Question 11

what does DNA tell amino acids to do

Answer 11

how to line up and form themselves into protein shapes

Question 12

DNA lives in… amino acids live in…

Answer 12

DNA= nucleus
amino acids= cytoplasm

Question 13

whats RNA

Answer 13

like DNA but shorter and is missing one side

Question 14

what is RNA able to do and how do they do it

Answer 14

RNA can go out the cytoplasm and into the ribosomes, which reads RNA codes and sticks them together in a chain which forms a perfect protein

Question 15

explain the sequence ish of DNA, RNA, etc

Answer 15

DNA makes RNA which makes proteins which makes life or what not

Question 16

what are the 4 possible nitrogenous bases that make up the nucleotides of DNA

Answer 16

• adenine (A)
• guanine (G)
• thymine (T)
• cytosine (C)

Question 17

who discovered the key relationships between nitrogenous bases, and what are they

Answer 17

in 1940, erwin chargaff discovered the relationship between the bases
- the amount of adenine = amount of thymine
- amount of guanine = amount of cytosine

Question 18

what did the discovery of the relationship of the bases help with

Answer 18

helped determine the structure of DNA

Question 19

what did rosalind franklin do

Answer 19

while working with maurice wilkins, she discovered that the DNA molecules must have a helix or corkscrew shape

Question 20

how did james franklin and francis crick determine the structure of DNA

Answer 20

they met with wilkins and saw the image that rosalind had taken- then they built a model and determined that DNA had the double helix shape

Question 21

what did the model of the structure of DNA account for (what facts)?

Answer 21

• that DNA is made of a pentose sugar, a phosphate group, and nitrogenous bases
• the proportion of A-T and C-G is equal
• DNA has the shape of a helix