DNA Structure
The structure of the DNA molecule is called a _____ ____.
double helix
According to Chargraff's rules for complimentary base pairs adenine (A) always pairs with the base _______ in the complimentary strand of DNA.
thymine (T)
DNA replication means that the cell is _________ the DNA. Another term for replication.
copying
The longest phase of the cell cycle. The cell spends 90% of its time in this phase.
interphase
The shortest phase of the cell cycle where the division of the nucleus and the cell actually occur. The cells spends about 10% of its life in this stage.
M-phase
nucleotides
According to Chargraff's rules for complimentary base pairs guanine (G) always pairs with the base _______ in the complimentary strand of DNA.
cytosine (C)
So that there is enough for both cells to have the right amount of DNA when they split.
Replication of DNA occurs during this stage of interphase of the cell cycle.
the S phase or synthesis phase
This type of sugar is found in the nucleotides that make up DNA molecules.
deoxyribose
True or False: DNA is found in all living organisms.
true
The 3 parts of a nucleotide are the ________, _______, & __________.
In DNA replication, this enzyme is responsible for unzipping the DNA molecule by breaking the hydrogen bonds between the nitrogen bases. A replication fork is created when this happens.
helicase
During this first stage of interphase, the cell is growing larger and taking in nutrients. The most important check point of the cell cycle occurs after this stage.
G1
DNA replication is said to be _______-__________ because the process always results in one old parent DNA strand being paired one new daughter DNA strand.
semi-conservative
DNA stand for ________________.
deoxyribonucleic acid
These types of bonds hold together the rungs of the DNA double helix.
hydrogen bonds
This enzyme is responsible for gluing back together the fragmented pieces of the new daughter strand of the lagging strand after replication is complete.
ligase
During the third stage of interphase, the cell is growing larger, taking in nutrients, and prepares itself for the M-phase by making sure it has the right amount of organelles and other cellular components.
G2
When you look at a DNA molecule, you notice that one strand's sugar and phosphate backbone molecules are flipped in orientation from the other strand's backbone molecules. These strands are said to be ___________.
antiparallel
Variations (different choices) in traits are controlled by varying sequences of which part of the DNA structure?
nitrogenous bases or bases
These phosphate and deoxyribose sugar make up the ________ of the DNA molecule.
backbone
This enzyme is responsible for creating the new DNA daughter strand by grabbing onto the nucleotides with complimentary bases that match those on the old DNA parent strand and adding them to the growing strand.
DNA polymerase
This check point is the most important check point of the cell cycle. It happens right after the G1 phase. If the cell is not ready to divide, it will pull itself out of the cell cycle and carry on with its normal, everyday functions without preparing to divide.
G1 check point
When a scientist mixed the DNA from a rabbit with the DNA of a dog, she found that some of the DNA from the rabbit paired up with some of the DNA from the dog. This is possible because...
Similar nucleotides are present in both organisms. A always pairs with T and C pairs with G.