Chapter 12: The Cell Cycle Flashcards
Define Cell Division
The reproduction of cells.
Define Cell Cycle
An ordered sequence of events in the life of a cell, from its origin in the division of a parent cell until its own division into two. The eukaryotic cell cycle is composed of interphase (including G1, S, and G2 Phases) and M phase (including mitosis and cytokinesis).
Most cell division results in genetically _____ daughter cells.
Identical
Define Genome
The genetic material of an organism or a virus.
The typical length of DNA in a human cell is _____.
2m
Define Chromosome
A cellular structure consisting of one DNA molecule and associated protein molecules. A eukaryotic cell typically has multiple, linear chromosomes, which are located in the nucleus. A prokaryotic cell often has a single, circular chromosome, which is found in the nucleoid, a region that is enclosed by the membrane.
Define Chromatin
The complex of DNA and proteins that makes up eukaryotic chromosomes. When the cell is not dividing chromatin exists in its dispersed form, as a mass of very long, thin fibers.
Define Somatic Cells
Any cell in a multicellular organism except a sperm or egg or their precursors.
How many chromosomes do somatic cells contain?
46
Define Gamete
A haploid reproductive cell, such as an egg or sperm, that is formed by meiosis or is the descendant of cells formed by meiosis. Gametes unite during sexual reproduction to produce a diploid zygote.
Each duplicated chromosome consists of _____.
Two sister chromatids.
Define Sister Chromatids
Two copies of a duplicated chromosome attached to each other by proteins at the centromere and, sometimes, along the arms. While joined, two sister chromatids make up one chromosome. Chromatids are eventually separated during mitosis or meiosis II.
The two chromatids, each containing an identical DNA molecule, are typically attached all along their lengths by protein complexes called _____.
Cohesins
Define Centromere
In a duplicated chromosome, the region on each sister chromatid where it is most closely attached to its sister chromatid by proteins that bind to the centromeric DNA.
Once the sister chromatids separate, they are no longer called sister chromatids; rather, they are considered ______.
Chromosomes
Define Mitosis
A process of nuclear division in eukaryotic cells conventionally divided into 5 stages: Prophase, Prometaphase, Metaphase, Anaphase, Telophase. Mitosis conserves chromosome numbers by allocating replicated chromosomes equally to each of the daughter nuclei. PP-MAT
Define Cytokinesis
The division of the cytoplasm to form two separate daughter cells immediately after mitosis, meiosis I, or meiosis II.
Define Mitotic (M) Phase
The phase of the cell cycle that includes mitosis and cytokinesis.
The _____ phase is the shortest portion of the cell cycle.
Mitotic
Define Interphase
The period in the cell cycle when the cell is not dividing. During interphase, cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase. Interphase often accounts for about 90% of the cell cycle.
What are the three phases that interphase can be divided in?
G1-S-G2
Define G1 Phase
The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins.
Define S Phase
The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.
Define G2 Phase
The second gap, or growth phase, of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.
