DNA Basics
This molecule contains the "sets of instructions" for building proteins and is passed from parents to offspring.
DNA (Deoxyribonucleic acid)
The stage of the cell cycle where DNA is replicated.
S Phase
The phase where chromosomes line up in the center of the cell.
Metaphase
This is the phase of the cell cycle where the cell is not actively dividing.
Interphase
This is a functional segment of DNA that codes for a specific protein.
a gene
These short segments of DNA are found only on the lagging strand.
Okazaki fragments
According to the videos, the "M" in Mitosis should make you think of this word.
"Middle" or "Move" or "More cells
What is Deoxyribonucleic Acid?
DNA
This term refers to the actual division of the cytoplasm to form two new daughter cells.
Cytokinesis
These are the three components that make up a single nucleotide.
sugar (deoxyribose), a phosphate group, and a nitrogenous base
A resting state where cells perform their functions but do not prepare for division.
G0
The phase where the nuclear envelope reforms and two nuclei appear.
Telophase
During this specific sub-phase of Interphase, DNA replication occurs.
S phase (Synthesis phase)
This term describes a pair of chromosomes that contain the same types of genes in the same order—one from the mother and one from the father
homologous chromosomes
This strand is synthesized continuously toward the replication fork.
the Leading Strand
This type of reproduction produces offspring identical to the parent.
Asexual Reproduction
This monomer of DNA consists of a sugar, a phosphate, and a base.
Nucleotide
The cell cycle is essential for these three things: growth, healing/repair, and maintaining this (internal balance).
homeostasis
In the DNA "ladder," the sugar and phosphate form this part of the structure, while the nitrogenous bases form the "rungs."
the sugar-phosphate backbone
This phase follows G1 but precedes (comes before) G2.
S Phase
This is the phase where sister chromatids are finally pulled apart toward opposite ends of the cell.
Anaphase
What do we call uncontrolled cell growth caused by a breakdown in cell cycle regulation?
Cancer
In eukaryotes, DNA is wound around proteins to form this structure.
chromosome
DNA is described as "antiparallel." If one strand is 5' to 3', the other is ___.
3'-5'
DNA replication is "Semi-___" because it keeps half of the original strand.
Semi-conservative
The bond between nitrogenous bases (A-T, C-G) is called...
a Hydrogen Bond
This structure reappears inside the newly forming nuclei during Telophase.
the nucleolus
According to the base-pairing rules, Cytosine (C) always bonds with Guanine (G), and Adenine (A) always bonds with this.
Thymine (T)
Draw the four stages of mitosis (PMAT) from memory on a blank sheet of paper. If you can draw where the DNA, the spindle fibers, and the membrane are at each step without looking at your notes, you’ve got it.
Compare your drawing to your study guide!
In Telophase, the chromosomes begin to do this, returning to their "normal" stringy form.
decondense
This checkpoint is the most important "restriction point"—if the cell passes it, it usually completes the whole cycle.
G1 Checkpoint
Human somatic cells have this many chromosomes.
46
These proteins keep the nitrogenous bases from re-bonding after helicase passes through.
SSB Proteins
This structure is formed in plant cells during cytokinesis instead of a cleavage furrow.
a Cell Plate
This enzyme replaces RNA primers with DNA nucleotides.
DNA Polymerase I
Cytokinesis is not a separate step at the very end; it actually overlaps with these two phases of mitosis.
Anaphase and Telophase
If a cell has a mutation that disables Primase, what is the immediate result?
DNA Polymerase will never be able to start building new strands.
A scientist notices a cell with twice the normal amount of DNA, but only one nucleus. What phase did it likely just finish?
S Phase
If a drug prevents spindle fibers from shortening, which specific stage of mitosis will be blocked?
Anaphase
During the G1 phase, the cell grows and synthesizes proteins needed for this specific process.
DNA replication
If a cell starts prophase with 10 chromosomes, how many chromatids are present?
20
Why must the lagging strand be built in fragments?
Because DNA polymerase only works 5' to 3', and the lagging strand runs in the opposite direction of the opening fork.
In a 24-hour cell cycle, Mitosis usually takes about 1-2 hours. What does this tell you about Interphase?
It is the longest part of the cycle/takes up the vast majority of the time.
If a cell skips the G2 checkpoint and enters Mitosis with unreplicated DNA, what will be the result for the daughter cells?
They will have an incorrect or incomplete amount of DNA/mutations.
These are the weak chemical bonds that hold the two polynucleotide strands together.
hydrogen bonds
Plant vs. Animal Cells
Your notes show a rounded cell (likely an animal cell). Remember that in plant cells, cytokinesis involves forming a cell plate because their rigid cell walls can't just "pinch" in half. (look at the diagrams)
These specific structures (labeled in the diagrams) are responsible for pulling the chromosomes toward the poles.
kinetochore microtubules?
In this final stage of Interphase, the cell makes more organelles and organizes itself for the upcoming mitotic phase.
G2 phase
Because single-celled organisms like bacteria produce offspring with virtually identical DNA via mitosis, their offspring are often called this.
clones
1. Why do chromosomes condense?
2.Why does the nuclear envelope break down?
(This is not from the videos, but important to know.)
1. To make them easier to move without tangling/breaking
2. To allow the spindle fibers access to the chromosomes.
In this final stage of Interphase, the cell makes more organelles and organizes itself for the upcoming mitotic phase.
G2
Chromatid vs. Chromosome
Be sure you can distinguish between a single "chromatid" and a "sister chromatid pair." In Anaphase, they are pulled apart; once they are separate, they are each considered a full chromosome.