Cell Division: Mitosis, Meiosis, and Chromosome Biology

A set of vocabulary flashcards defining key structures, stages, and concepts of cell division, mitosis, and meiosis covered in the lecture.

Interphase

A stage of the cell cycle where the cell is not dividing, characterized by decondensed DNA, an intact nuclear membrane, and a visible nucleolus.

Telophase

The final stage of nuclear division in mitosis, identified by two distinct nuclear regions forming for the daughter cells and the reformation of nuclear envelopes.

Cell Plate

A structure that forms between two new daughter cells during division in plant cells, representing the formation of the new cell wall.

Sister Chromatids

An $X$-shaped structure consisting of a condensed chromosome paired and attached to its exact duplicated copy.

Chromatin

The combination of DNA and its supporting proteins, referred to as chromatin whether condensed or decondensed.

Histones

Supporting protein bead-like structures around which DNA wraps to compact and organize inside the chromosome.

Centromere

The middle adhering region that connects duplicated sister chromatids together, containing no active genes.

Gene

An active coding region of DNA that opens up to allow a protein to be synthesized from its sequence.

Telomeres

Protective structures located at the ends of chromosomes that prevent them from sticking together and causing abnormalities leading toward cancer.

Diploid

Having two complete sets of chromosomes, representing the normal chromosome number of a sexually reproducing body cell ($46$ in humans).

Haploid

Having half the number of chromosomes found in a normal body cell, characteristic of gametes ($23$ in human sex cells).

Autosomes

The $22$ homologous pairs of chromosomes in human cells that do not determine biological sex.

Mitosis

A process of nuclear division in asexual cell division where a single parent cell divides to form two identical clone daughter cells.

Meiosis

The foundational cell division process for sexual reproduction that yields four genetically unique haploid gametes per division.

Gametes

A general biological term for sex cells, specifically sperm cells and egg cells, which are genetically unique and haploid.

Centrioles

Paired cytoskeletal structures characteristic of animal cells that help orchestrate the separation of chromosomes during division.

Asters

Microtubules of the cytoskeleton that position and move centrioles during cell division.

Cytokinesis

The physical division of the cytoplasm and non-nuclear organelles, including the Golgi apparatus and endoplasmic reticulum, into daughter cells.

Zygote

The first diploid cell of a developing organism, formed at fertilization and possessing totipotent capabilities.

Reproductively Fit Adult

The body form of an organism within its life cycle that is biologically capable of producing gametes for sexual reproduction.

Gametogenesis

The process of meiosis occurring in the ovaries or testes to generate functional gametes.

Prophase

The first stage of mitosis, during which the nuclear membrane begins breaking down and chromatin condenses into distinct sister chromatids.

Spindle Fibers

Microtubule fibers that attach directly from the centriole to the centromere of chromosomes to facilitate separation.

Anaphase

The mitotic phase where spindle fibers shorten, pulling sister chromatids apart so that their trailing arms form distinct $V$-shaped structures.