Cell Division Flashcards
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What is the cell cycle?
The cell cycle is the series of events through which a cell grows, duplicates its DNA, and divides to produce two daughter cells.
What are the types of cells and their division frequency?
Rapidly dividing cells: Skin cells, intestinal lining cells.
Rarely dividing cells: Nerve cells, muscle cells.
What is mitosis, and what is its function?
Mitosis is the process of nuclear division in somatic cells that ensures each daughter cell receives an identical set of chromosomes. Its main function is growth, repair, and replacement of cells.
How many daughter cells are produced during mitosis?
Two daughter cells.
What is the chromosomal content of daughter cells after mitosis?
Daughter cells are diploid (2n), with the same number of chromosomes as the parent cell.
What are the key events of prophase?
— Chromatin condenses into visible chromosomes.
— The nuclear membrane breaks down.
— The mitotic spindle begins to form.
What is the role of centrioles in mitosis?
Centrioles organize the spindle fibers, which help separate sister chromatids during mitosis.
What is a parent cell?
The original cell that divides to produce daughter cells.
What is a daughter cell?
The two genetically identical cells produced from a parent cell during mitosis.
What are sister chromatids?
The two identical copies of a chromosome connected by a centromere after DNA replication.
What is a centromere?
The region of a chromosome where sister chromatids are joined and where spindle fibers attach during mitosis.
How many cells are produced during meiosis?
Four daughter cells.
What is the chromosomal content of daughter cells after meiosis?
Daughter cells are haploid (n), containing half the number of chromosomes as the parent cell.
How many divisions occur during meiosis?
Two divisions: meiosis I and meiosis II.
Does synapsis and crossing over occur in mitosis or meiosis?
Synapsis and crossing over occur only in meiosis during prophase I, not in mitosis.
What is the relationship between DNA, chromosomes, and chromatin?
— DNA is the genetic material that carries instructions for life.
— Chromosomes are condensed structures of DNA and proteins visible during cell division.
— Chromatin is the uncondensed form of DNA found in the nucleus during interphase.
What regulates the progression of the cell cycle?
Cyclins and cyclin-dependent kinases (CDKs) regulate the cell cycle by ensuring proper progression through checkpoints.
What happens when the cell cycle is not properly regulated?
Unregulated cell division can lead to cancer, where cells divide uncontrollably and invade other tissues.
What happens during the G1 phase of interphase?
The cell grows, produces organelles, and performs its normal functions.
What happens during the S phase of interphase?
DNA replication occurs, and each chromosome duplicates to form sister chromatids.
What happens during the G2 phase of interphase?
The cell prepares for mitosis by synthesizing proteins and ensuring that all DNA is properly replicated.
How does cytokinesis differ in plant and animal cells?
— In animal cells, cytokinesis occurs through the formation of a cleavage furrow.
— In plant cells, cytokinesis occurs through the formation of a cell plate.
Do plant cells have centrioles?
No, plant cells do not have centrioles, but they can still form a spindle apparatus.
What is independent assortment, and when does it occur?
Independent assortment is the random orientation of homologous chromosomes during metaphase I of meiosis, leading to genetic variability.
