unit 8

Question 1

what are chromosomes made out of?

Answer 1

DNA pieces coiled around proteins called histones

Question 2

DNA is what kind of molecule and what is it’s function?

Answer 2

DNA is a macromolecule (nucleic acid) and its function is to share genetic information

Question 3

how many and what kind of DNA are there?

Answer 3

DNA and RNA

Question 4

nucleotides are made up of 3 parts, what are they?

Answer 4

sugar (5-carbon), phosphate, nitrogen base

Question 5

where does DNA nucleotide stay?

Answer 5

stays inside the nucleus

Question 6

where does RNA nucleotide stay?

Answer 6

stays in and outside nucleus

Question 7

DNA nucleotides are made up of–

Answer 7

a deoxyribose sugar, phosphate, and 4 nitrogen base

Question 8

what are the four nitrogen bases DNA nucleotides are made up of?

Answer 8

adenine, guanine, cytosine, thymine

Question 9

what is the shape of DNA?

Answer 9

two strands connected, shape of a twisted ladder-double helix

Question 10

what makes up the sides of the rails of the double helix of DNA?

Answer 10

sugar and phosphate

Question 11

true or false: DNA has directionality: read from 5’ to 3’

Answer 11

true

Question 12

the strands of DNA run in what direction?

Answer 12

they run in opposite directions, antiparallel

Question 13

the 5’ (5 prime) end is at the–

Answer 13

phosphate

Question 14

the 3’ (3 prime) end is at the–

Answer 14

sugar

Question 15

DNA codes for–

Answer 15

proteins

Question 16

Erwin Chargaff–

Answer 16

discovers the rules of base pairing: A-T, G-C

Question 17

Rosalind Franklin & Maurice Wilkins–

Answer 17

determined that the DNA molecule was a coiled spiral, they used a technique called x-ray diffraction

Question 18

James Watson & Francis Crick–

Answer 18

determined the exact structure of DNA, received the Nobel prize in 1962

Question 19

DNA replication–

Answer 19

-occurs in the nucleus of eukaryotes and in the cytoplasm of prokaryotes
-occurs during interphase (S phase) in eukaryotes
-there are approximately 6 billion pairs of nucleotides in human body cells (3 billion in haploid)
-it takes about six hours to copy all your DNA
-a DNA molecule produces 2 identical copies of iteslf

Question 20

steps in DNA replication–

Answer 20

1. enzymes unwind and unzip the DNA double helix
2. the enzyme DNA polymerase brings complementary nucleotides and attaches them to the matching nucleotides in the open strands

Question 21

why is DNA replication called semiconservative?

Answer 21

it is called that because two copies of the original DNA molecule are produced, each copy replicating the info from one half of the original DNA molecule.

Question 22

DNA=