DNA Discovery History
This scientist's work with pea plants in 1866 laid the foundation for the field of genetics.
who is gregor mendel
These are the three components that make up a single DNA nucleotide
what are nitrogenous base, deoxyribose sugar, and phosphate group
This enzyme is responsible for unwinding and unzipping the DNA double helix at the replication fork
helicase
This phase of interphase is where the cell undergoes its primary growth and doubles its size
G1
During this phase of mitosis, chromosomes align along the equatorial plane of the cell
metaphase
Using "Photo 51" obtained by X-ray crystallography, this scientist concluded that DNA was a double helix with an antiparallel sugar-phosphate backbone
who is rosalind franklin
This term describes the opposite orientation of the two DNA strands, where one runs 5’ to 3’ and the other runs 3’ to 5’
antiparallel
Because DNA polymerase can only add nucleotides to the 3' end, this strand is synthesized in short segments called Okazaki fragments.
lagging strand
DNA replication specifically occurs during this phase of interphase
S phase
This stage is characterized by the physical separation of sister chromatids as they move toward opposite poles
anaphase
These two researchers used a phage known as T2 to provide final evidence that DNA (not protein) was the genetic material
These proteins are where DNA winds around to form nucleosomes
histones
This enzyme relieves the torsional strain (overwinding) ahead of the replication fork by adding nicks in the DNA
topoisomerase
This "resting" phase is occupied by non-dividing cells like mature nerve or cardiac cells
G0
In animal cells, cytokinesis is achieved through the formation of this structure that constricts the cell inward
cleavage furrow
This rule, named after the scientist who discovered it, states that in any species, the percentage of Guanine equals Cytosine, and Adenine equals Thymine
what is Chargaff's rule
This "beads on a string" structure represents the 10-nm fiber level of DNA packaging
nucleosome
Proven by Meselson and Stahl, this model of replication results in two daughter molecules that each contain one old parent strand and one new strand
semi-conservative replication
This internal checkpoint ensures that all chromosomes have been fully replicated and that the DNA is not damaged before entering mitosis
G2
Unlike animal cells, plant cells must form this structure from vesicles to build a new cell wall between daughter cells
cell plate
These two scientists won the race to build a double helix model of DNA in 1953
who were Watson and Crick?
This form of chromatin is densely packed and usually contains DNA that is not expressed
heterochromatin
This enzyme is required to seal the gaps between Okazaki fragments by forming phosphodiester bonds
DNA ligase
These (hint: two word) proteins hold sister chromatids together at the centromere until they are ready to separate
cohesion proteins
This mitotic stage involves the nuclear envelope reforming around each set of chromosomes and the spindles depolymerizing
telophase