A1.2 HL only

Question 1

Leading strand

Answer 1

the strand of nascent DNA which is synthesized in the same direction as the growing replication fork

Question 2

replication fork

Answer 2

the area where the replication of DNA will actually take place

Question 3

Lagging strand

Answer 3

one of two strands of DNA found at the replication fork, or junction, in the double helix

Question 4

template strand

Answer 4

the strand that is used during transcription to produce RNA

Question 5

coding strand

Answer 5

the DNA strand whose base sequence is identical to the base sequence of the RNA transcript

Question 6

ribosome

Answer 6

an intercellular structure made of both RNA and protein, and it is the site of protein synthesis in the cell

Question 7

DNA polymerase II

Answer 7

enzyme in DNA replication that checks for mistakes and repairs them

Question 8

euchromatin

Answer 8

the less tightly coiled DNA that allows transcription factors and chromatin remodelers access, enabling transcription to occur

Question 9

Nucleosome

Answer 9

a section of DNA that is wrapped around a core of proteins

Question 10

heterochromatin

Answer 10

the highly coiled DNA that is no longer used in protein synthesis

Question 11

Supercoil

Answer 11

a highly wound, wrapped, and condensed DNA strand

Question 12

Chromosome

Answer 12

made up of proteins and DNA organized into genes

Question 13

cell division

Answer 13

cell cycle in which the cell grows and replicates its chromosome(s) beforedividing

Question 14

histones

Answer 14

a protein that provides structural support for a chromosome

Question 15

octamer

Answer 15

The complex of eight histone proteins

Question 16

H1 histone protein

Answer 16

plays a dominant role in establishing the compaction state of an array ofnucleosomesas well as influencing the conformation

Question 17

transcription factors

Answer 17

a proteinthat controls the rate of transcription of genetic information from DNA to messenger RNA

Question 18

prophase

Answer 18

the first phase of mitosis where chromosomes form

Question 19

Naked DNA

Answer 19

DNA that is not associated with proteins, lipids, or any other molecule to help protect it

Question 20

Thomas Morgan

Answer 20

biologist who discovered the inheritance pattern of genes located near each other on similar choromosomes

Question 21

Oswald Avery

Answer 21

biologist who discovered genes are made of DNA and its role in development

Question 22

Alfred Hershey

Answer 22

biologist who confirmed that DNA is the principle molecule in heredity

Question 23

Martha Chase

Answer 23

biologist who confirmed that DNA is the principle molecule in heredity

Question 24

bacteriophages

Answer 24

viruses that infect and replicate only in bacterial cells

Question 25

viral DNA

Answer 25

DNA viruses have DNA genomes that are replicated by either host or virally encoded DNA polymerases

Question 26

protein capsule

Answer 26

the protective structure surrounding viruses

Question 27

Radioactive isotopes

Answer 27

An unstable form of a chemical element that releases radiation as it breaks down and becomes more stable

Question 28

isotope 32P

Answer 28

A radioactive form of the element phosphorus. It is used in the laboratory to label DNA and proteins.

Question 29

isotope 35S

Answer 29

the most stable radioactive isotope of sulfur, used in biochemical research to radioactively label proteins

Question 30

pellet

Answer 30

The sedimented portion that accumulates during centrifugation

Question 31

supernatant

Answer 31

The soluble liquid reaction of a sample after centrifugation

Question 32

X-ray crystallography

Answer 32

a scientific field concerned with revealing the structure of matter at the atomic level. The essential method involves exposing a crystallised sample of a molecule to x-rays, usually with an instrument called an x-ray camera

Question 33

Erwin Chargaff

Answer 33

biologiest who discovered that in the DNA of any species and any organism, the amount of guanine should be equal to the amount of cytosine and the amount of adenine should be equal to the amount of thymine

Question 34

Rosalind Franklin

Answer 34

discovered the density of DNA and, more importantly, established that the molecule existed in a helical conformation. Her work to make clearer X-ray patterns of DNA molecules laid the foundation for James Watson and Francis Crick's suggestion that DNA is a double-helix polymer in 1953

Question 35

James Watson

Answer 35

biophysicist who played a crucial role in the discovery of the molecular structure of deoxyribonucleic acid (DNA)

Question 36

Francis Crick

Answer 36

important theoretical molecular biologist and played a crucial role in research related to revealing the helical structure of DNA