Cell Division and Reproductive Strategies

Flashcards covering cell division (mitosis and meiosis), various types of asexual and sexual reproduction, and plant vs. animal cell differences.

Mitosis

The process of dividing the cell nucleus used for growth or repair, producing two genetically identical diploid ($2n$) daughter cells.

Oncogenes

Genes that control how fast or how often cell division happens; if they mutate, they can cause uncontrolled cell division known as cancer.

Malignant

A type of tumor that will spread and is categorized as harmful or bad.

Benign

A type of tumor that will not spread and can usually be removed through surgery.

Chromatin

The non-dividing form of DNA that has a threadlike appearance; it exists during interphase and reappears during telophase.

Chromosome

The supercoiled form of DNA that appears during cell division; it consists of two chromatids attached at a centromere.

Interphase

The period between mitotic divisions including phases $G_1$, $G_0$, $S$, and $G_2$; it is a stage of growth and specialized function rather than division.

Supercoiling

The process in early prophase where the chromosomes shorten and thicken.

Asters

Star-shaped structures made of tubulin that grow around the centrioles.

Spindle

A football-shaped structure created by microtubules that extend from pole to pole and connect to centromeres to move chromosomes.

Metaphase

The stage of mitosis where the spindle fibers push and pull on double chromosomes to line them up at the cell's equator.

Anaphase

The phase characterized by the splitting of centromeres and the movement of chromatids toward opposite poles as the cell begins to stretch.

Cytokinesis

The division of the cytoplasm that often begins in late anaphase and results in the formation of two equal-sized daughter cells.

Cell Plate

A structure formed by Golgi bodies in plant cells during cytokinesis to build a new cell wall between daughter cells.

Homologous Chromosomes

Pairs of chromosomes that match in size, centromere location, and gene location.

Somatic Cells

Body cells that are diploid ($2n$) and undergo conservative division to grow and repair tissues.

Gametes

Reproductive cells (sperm or eggs) that are haploid ($n$) and produced through meiosis for sexual reproduction.

Synapsis

The process in Meiosis I where homologous chromosomes (tetrads) come together so that pieces of chromosomes can be exchanged.

Crossing Over

The exchange of genetic material between homologous chromosomes during prophase I, which introduces genetic variation.

Binary Fission

The method of asexual reproduction used by prokaryotes, which can occur every $20\,\text{minutes}$ in favorable conditions.

Plasmid DNA

Self-replicating loops of DNA in bacteria that can contain 'bonus' genes like antibiotic resistance.

Budding

A form of asexual reproduction where a complete miniature version of the adult grows out of the parent, such as in Hydra.

Fragmentation

A reproduction strategy where a part of an individual is broken or cut, and the fractured piece grows into a new individual, such as in starfish.

Parthenogenesis

A process where unfertilized eggs develop into adults, as seen in the production of haploid male honeybees.

Spores

Specialized, non-metabolically active reproductive cells protected by a cell wall that can travel great distances via wind or water.

Angiosperms

Flowering plants that represent the most widespread and diverse group of plants.

Oogenesis

The production of an ovum (egg cell) through meiosis, characterized by unequal division to store nutrients into one large cell.