Diploid vs Haploid Cells - Quick Reference

Somatic Cells (Body Cells)

• Definition: body cells, non-sex cells.
• Examples: skin, brain, nerve, muscle, white blood cells, red blood cells.
• Diploid nature: somatic cells are diploid; they have paired chromosomes.
• Humans have 23 pairs, totaling 46 chromosomes: $23$ pairs and $46$ chromosomes.
• Each pair consists of one chromosome from each parent.

Karyotype and Chromosome Organization

• When chromosomes are organized in order, it is called a karyotype.
• Diploid cells have two of each chromosome (paired): two chromosome 1s, two chromosome 2s, etc.
• Humans have two copies of each chromosome: one from mother, one from father.

Mitosis (Diploid Cell Division)

• Diploid cells are produced by mitosis.
• Stages (in order): Interphase; Prophase; Metaphase (chromosomes lined up in the middle);
  Anaphase (sister chromatids pulled apart);
  Telophase (nuclei reform); Cytokinesis (cytoplasm divides) -> two diploid daughter cells.

Gametes and Haploid Cells

• Gametes are sex cells; haploid.
• Female gametes: eggs (ova); male gametes: sperm.
• In ovaries, eggs are produced; in testes, sperm are produced.
• Haploid cells have a single set of chromosomes; not paired.
• Human haploid number: $23$; each egg or sperm contains $23$ chromosomes.

Meiosis (Formation of Haploid Gametes)

• Meiosis consists of two rounds of division: Meiosis I and Meiosis II.
• One diploid cell gives rise to four haploid cells after meiosis II.

Quick Comparison: Diploid vs Haploid

• Diploid: paired chromosomes; total $46$; somatic cells; produced by mitosis.
• Haploid: single set of chromosomes; total $23$; gametes; produced by meiosis.
• Karyotype differences: Diploid shows paired chromosomes; Haploid shows single chromosomes.