Cell Division and Reproduction Quiz

Study Notes

Cell division is the process by which cells replicate.
Cell division is essential for the growth and development of multicellular organisms, and also for repair and replacement of damaged cells.

Asexual reproduction involves the production of offspring from a single parent, with offspring genetically identical to the parent.
Sexual reproduction involves two parent cells joining to produce offspring with a combination of genetic material from both parents.

Prokaryotes have circular chromosomes.
Binary fission involves the following steps:
- Replication of the chromosome
- Separation of the copies to opposite ends of the cell
- Division of the cell into two daughter cells

Eukaryotic chromosomes are linear and made of DNA with proteins.
Chromatin consists of the complex of DNA and proteins.
Sister chromatids are identical copies of a chromosome held together at the centromere.

The eukaryotic cell cycle is a series of stages that a cell goes through from its formation to its division.
Cell cycle phases include:
- Interphase:
  - G1: Cell growth and normal function
  - S: DNA Replication
  - G2: Preparation for division
- Mitotic Phase:
  - Mitosis: Nuclear division
  - Cytokinesis: Cytoplasm division

The cell cycle is regulated by a control system with checkpoints.
Checkpoints ensure correct replication and division by monitoring the environment and cell readiness.
G0 phase: A resting state where cells temporarily exit the cell cycle.

Cancerous cells differ from healthy cells by:
- Uncontrolled growth and division
- Ability to invade other tissues
- Ability to metastasize (spread to other parts of the body)
Benign tumors remain localized.
Malignant tumors spread and can be fatal.

Somatic cells are non-reproductive cells of the body.
Most somatic cells are diploid, meaning they contain two sets of chromosomes, one from each parent.
Homologous pairs are chromosomes with the same genes, one from each parent.
Autosomes are chromosomes that are not sex chromosomes.
Sex chromosomes determine sex (X and Y in humans).
Locus: The specific location of a gene on a chromosome.

Meiosis is a type of cell division that produces four haploid daughter cells from a single diploid cell.
Meiosis I:
- Prophase I: Condensation of chromosomes, synapsis (pairing of homologous chromosomes), crossing over (exchange of genetic material between non-sister chromatids)
- Metaphase I: Alignment of homologous chromosome pairs at the metaphase plate
- Anaphase I: Separation of homologous chromosome pairs, moving to opposite poles
- Telophase I: Formation of two daughter nuclei, each with one chromosome from each homologous pair.
Meiosis II: Similar to mitosis, but starting with haploid cells.
- Sister chromatids separate, resulting in four haploid daughter cells.
Tetrad: Pair of homologous chromosomes, comprised of four chromatids altogether.
Kinetochore: A protein structure at the centromere that attaches to spindle fibers.

Both involve chromosome duplication.
Mitosis results in two identical diploid daughter cells for growth and repair.
Meiosis results in four genetically different haploid daughter cells for sexual reproduction.

Independent orientation: The random lining up of homologous chromosome pairs during Meiosis I.
Random fertilization: The fusion of any sperm with any egg.
Crossing-over: The exchange of genetic material between non-sister chromatids.
Chiasma: The point of contact between non-sister chromatids during crossing over.

Karyotyping: A visual display of all chromosomes in a cell.
Karyotyping is performed to:
- Detect chromosome abnormalities
- Identify the sex of an individual
- Determine the genetic basis of certain diseases.