Cell Reproduction and Mitosis: Key Concepts for Biology 111

Zygote

A fertilized egg that results from the union of a sperm and an egg.

Genome

The complete set of genes or genetic material present in a cell or organism.

Prokaryotic Genome

Typically consists of a single circular chromosome and lacks membrane-bound organelles.

Eukaryotic Genome

Consists of multiple linear chromosomes and contains membrane-bound organelles.

Importance of Mitotic Cell Division

Essential for growth, development, and tissue repair in multicellular organisms.

Somatic Cell

Any cell of a living organism other than the reproductive cells.

Gamete

A reproductive cell that unites with another to form a zygote.

Diploid

A cell containing two complete sets of chromosomes, one from each parent.

Haploid

A cell containing a single set of unpaired chromosomes.

Homologous Chromosomes

Chromosome pairs, one from each parent, that are similar in shape, size, and genetic content.

Karyotype

A visual representation of the complete set of chromosomes in an organism.

Autosomes

Chromosomes that are not sex chromosomes.

Sex Chromosomes

Chromosomes that determine the sex of an individual.

Genes

Units of heredity that contribute to an organism's traits.

Loci (Locus)

Specific locations of genes on a chromosome.

Traits

Characteristics or features of an organism that are inherited.

Alleles

Different versions of a gene that determine distinct traits.

Histone Proteins

Proteins that help package and order DNA into structural units called nucleosomes.

Nucleosomes

Units of DNA wrapped around histone proteins, forming the basic structural unit of chromatin.

Chromatin Fiber

A complex of DNA and protein found in the nucleus that condenses to form chromosomes.

Duplicated Chromosomes

Chromosomes that have been replicated and consist of two sister chromatids.

Sister Chromatids

Identical copies of a chromosome connected by a centromere.

Cohesin Proteins

Proteins that hold sister chromatids together until they are separated during cell division.

Centromere

The region of a chromosome where the two sister chromatids are joined.

Cytokinesis

The process during cell division in which the cytoplasm divides, forming two daughter cells.

Cleavage Furrow

The indentation that begins the process of cytokinesis in animal cells.

Cell Plate

The structure that forms during cytokinesis in plant cells, leading to the separation of the two daughter cells.

G0 Phase

A resting phase where cells are not actively dividing and can be temporary or permanent.

Cell Cycle Checkpoints

Regulatory points in the cell cycle that ensure proper division and function.

Cdk/Cyclin Complex

A protein complex that regulates the cell cycle progression.

p53

A tumor suppressor protein that regulates the cell cycle and prevents cancer.

p21

A protein that inhibits the cell cycle and is regulated by p53.

Retinoblastoma (Rb)

A tumor suppressor protein that regulates the cell cycle by inhibiting progression from G1 to S phase.

Cancer

A disease characterized by uncontrolled cell division and growth due to mutations in cell cycle regulators.

Proto-Oncogenes

Normal genes that can become oncogenes when mutated, leading to cancer.

Tumor Suppressor Genes

Genes that protect a cell from one step on the path to cancer; mutations can lead to loss of function.

Prokaryotic Binary Fission

A method of asexual reproduction in prokaryotes where a single cell divides into two identical cells.

Eukaryotic Cell Division

A complex process involving mitosis and cytokinesis, resulting in two genetically identical daughter cells.