Cell Division and Mitosis Overview

Cell Division

Process by which a parent cell divides into two daughter cells.

Eukaryotic Chromosomes

Structures made of DNA and proteins in eukaryotic cells.

Cell Cycle

Life cycle of a cell from formation to division.

Mitosis

Nuclear division resulting in genetically identical daughter cells.

Meiosis

Cell division producing gametes with half chromosome number.

Asexual Reproduction

Reproduction involving a single organism, like Amoeba.

Binary Fission

Type of cell division in prokaryotes and unicellular eukaryotes.

Zygote

Fertilized egg that develops into a multicellular organism.

Cell Cycle Control System

Regulatory system ensuring proper cell cycle progression.

Checkpoint Proteins

Proteins that monitor and regulate the cell cycle.

Genome

Complete set of genetic information in a cell.

Karyotype

Visual representation of an organism's complete set of chromosomes.

Somatic Cells

All body cells except reproductive cells, containing 46 chromosomes.

Gametes

Reproductive cells (sperm and egg) with 23 chromosomes.

Ploidy

Number of sets of chromosomes in a cell.

Diploid

Cells with two sets of chromosomes (2n), like humans.

Haploid

Cells with one set of chromosomes (n), like gametes.

Homologous Chromosomes

Chromosome pairs with similar structure and genetic content.

Chromatin

Complex of DNA and proteins forming chromosomes.

Histone Proteins

Proteins that help package DNA into chromatin.

Chromosome Structure

Linear DNA molecule associated with proteins.

Cellular Organization

Arrangement of genetic material within a cell.

Eukaryotic Cell Size

Typical size ranges from 10 to 100 µm.

DNA Length in Cells

Human cell DNA length is about 2 meters.

Autosomes

Non-sex chromosomes; humans have 22 pairs.

Sex Chromosomes

Chromosomes determining sex; XX or XY in humans.

Cell Division Regulation

Highly regulated series of events in cell division.

Mitotic Spindle

Structure that separates chromosomes during mitosis.

Nucleosome

DNA wrapped around histones forming a unit.

Linker DNA

Connects nucleosomes like beads on a string.

10-nm fiber

Initial DNA structure formed by nucleosomes.

30-nm fiber

Thicker fiber formed by coiled nucleosomes.

300-nm fiber

Formed by looped domains attached to nuclear matrix.

Metaphase chromosome

Highly condensed chromosome during cell division.

Sister chromatids

Identical copies of a replicated chromosome.

Centromere

Region where sister chromatids are joined.

Cohesins

Proteins that hold sister chromatids together.

Eukaryotic cell cycle

Sequence from cell formation to division.

Interphase

Phase where cell grows and DNA replicates.

Mitotic phase

Shortest phase involving mitosis and cytokinesis.

G1 phase

First growth phase, lasts 8-10 hours.

S phase

DNA synthesis phase, lasts 6-8 hours.

G2 phase

Second growth phase, lasts 4-6 hours.

Cytokinesis

Division of cytoplasm and its contents.

Prophase

Chromosomes condense and spindle begins to form.

Prometaphase

Nuclear envelope fragments, spindle fibers attach.

Metaphase

Chromosomes align at the metaphase plate.

Anaphase

Sister chromatids separate and move apart.

Telophase

Nuclear membranes reform around separated chromosomes.

Chromosome duplication

Process of replicating chromosomes before division.

Radial loop domains

300-nm fiber loops attached to nuclear matrix.

Cell checkpoint

Regulatory point ensuring cell cycle progression.

Chromosome arm

Part of a chromosome extending from the centromere.

Nuclear matrix

Framework providing structure within the nucleus.

Duplicated chromosomes

Chromosomes that have undergone replication.

Cohesin Proteins

Proteins that hold sister chromatids together.

Kinetochore Microtubules

Microtubules that attach to chromatids during mitosis.

Polar Microtubules

Nonkinetochore microtubules that push cell poles apart.

Cleavage Furrow

Indentation indicating cytokinesis in animal cells.

Cell Plate

Structure forming between plant daughter cells during cytokinesis.

Somatic Cell Division

Produces two genetically identical daughter cells.

Centrosome

Microtubule organizing center defining spindle poles.

Aster

Radial array of microtubules from centrosome.

Metaphase Plate

Equatorial plane where chromosomes align during metaphase.

G1 Checkpoint

Control point assessing cell readiness to divide.

G0 Phase

Nondividing state for cells not receiving division signals.

Cyclins

Proteins regulating cell cycle checkpoints.

Cyclin-Dependent Kinases

Enzymes activated by cyclins to regulate cell cycle.

Cancer

Disease caused by uncontrolled cell cycle regulation.

Benign Tumor

Non-invasive tumor remaining at original site.

Malignant Tumor

Tumor that invades surrounding tissues and metastasizes.

Metastasis

Spread of cancer cells to distant body parts.

Checkpoints

Control points regulating cell cycle events.

M Phase

Phase of mitosis where cell divides.

S Phase

Phase where DNA is replicated.

G2 Phase

Phase preparing cell for mitosis.

Cytoplasmic Division

Process of dividing the cytoplasm during cytokinesis.