Cell and Nuclear Division Flashcards

Vocabulary practice flashcards covering cell cycle phases, plant and animal cytokinesis, mitosis, meiosis, and genetic variation based on the IB Biology syllabus.

Cell Cycle

The sequence of events including Interphase (G1, S-DNA replication, G2), Mitosis, and Cytokinesis through which a cell grows and divides.

Cytokinesis

The physical splitting of the cytoplasm in a parent cell between daughter cells following nuclear division.

Plant Cytokinesis

The process in plant cells where Golgi vesicles fuse to form a cell plate and build a cell wall containing pectin in the middle of the cell to divide it into two.

Animal Cytokinesis

The process in animal cells where a contractile ring of actin filaments constricts to pinch the cell membrane inward, forming a cleavage furrow that splits the cell into two.

Equal Cytokinesis

The standard form of cell division where cytoplasm and organelles are split equally, ensuring each daughter cell receives roughly half of the parent cell's organelles.

Unequal Cytokinesis

An asymmetric form of cytoplasm division where one resulting cell receives significantly more cytoplasm than the other, as seen in fungal budding and animal oogenesis.

Budding

A form of unequal cytokinesis in fungi where a mother cell forms an outgrowth of its cell wall with a small amount of cytoplasm, receives a nucleus, and buds off into a separate cell.

Oogenesis

The process of creating female egg gamete cells through unequal cytokinesis during meiosis, yielding one large haploid egg cell and small polar bodies that soon die.

Mitosis

A eukaryotic cell division process aimed at creating 2 daughter cells that are genetically identical to the mother cell.

Phases of Mitosis (PMAT)

The sequential stages of nuclear division in mitosis: Prophase, Metaphase, Anaphase, and Telophase.

Mitotic Micrograph Identification

The microscopic visualization of distinct nuclear division stages (Interphase, Prophase, Metaphase, Anaphase, Telophase) in stained plant or animal tissue.

S Phase (S-DNA replication)

The stage during interphase in which DNA is duplicated, serving as a prerequisite for both mitosis and meiosis so each new cell receives a complete set of genetic instructions.

Chromosome Supercoiling

The mechanism of condensation during which DNA strands wrap tightly around histone proteins and coil extensively to move safely during nuclear division.

Meiosis

A reduction division in eukaryotic cells that reduces the chromosome number from diploid to haploid, generating genetically varied cells that can develop into gametes.

Diploid

Refers to a cell containing two full sets of homologous chromosomes, represented as $2n$.

Haploid

Refers to a cell containing a single set of unpaired chromosomes, represented as $n$, typical of gametes.

Non-disjunction

A chromosome separation failure during Meiosis I or Meiosis II that results in gametes with abnormal chromosome numbers.

Down Syndrome

A developmental disorder caused by a non-disjunction mutation leading to trisomy 21 (an extra copy of chromosome 21).

Crossing Over

The exchange of genetic material between non-sister chromatids of homologous chromosomes during prophase I of meiosis, creating new allele combinations.

Random Orientation

The random arrangement of maternal and paternal homologous chromosome pairs along the metaphase plate in meiosis, generating genetic diversity in resulting gametes.