Biology Ch. 13-14 - Cellular Reproduction

Anaphase

The stage of mitosis where sister chromatids separate and are pulled to opposite poles of the cell by spindle fibers.

Anaphase I

The stage of meiosis I where homologous chromosome pairs (not sister chromatids) separate and move to opposite poles of the cell.

Anaphase II

The stage of meiosis II where sister chromatids finally separate and are pulled to opposite poles, similar to mitotic anaphase.

Metaphase

The stage of mitosis where chromosomes align at the cell's equator (metaphase plate) before separating.

Metaphase I

The stage of meiosis I where homologous chromosome pairs line up at the cell's equator.

Metaphase II

The stage of meiosis II where individual chromosomes (still consisting of sister chromatids) align at the equator.

Prophase

The first stage of mitosis where chromatin condenses into visible chromosomes, the nuclear envelope breaks down, and spindle fibers begin to form.

Prophase I

The first stage of meiosis I where homologous chromosomes pair up (synapsis), crossing

Prophase II

The stage of meiosis II where a new spindle apparatus forms in each haploid cell, similar to mitotic prophase but with half the chromosome number.

Telophase

The final stage of mitosis where chromosomes decondense, nuclear envelopes reform around each set of chromosomes, and the cell prepares to divide.

Telophase I

The stage of meiosis I where two haploid cells form, each containing one chromosome from each homologous pair.

Telophase II

The final stage of meiosis II where four haploid cells are produced, each with a single set of unreplicated chromosomes.

Cell cycle

The ordered sequence of events that a cell goes through from one division to the next, including interphase and cell division.

Interphase

The period between cell divisions when the cell grows, carries out normal functions, and replicates its DNA; consists of G1, S, and G2 phases.

G1 Phase

The first gap phase of interphase where the cell grows, produces proteins and organelles, and prepares for DNA replication.

S Phase

The synthesis phase of interphase where DNA replication occurs, resulting in duplicate copies of each chromosome.

G2 Phase

The second gap phase of interphase where the cell continues to grow, produces proteins needed for mitosis, and prepares for cell division.

Cytokinesis

The physical division of the cytoplasm that occurs after nuclear division, resulting in two separate daughter cells.

Mitosis

The type of cell division that produces two genetically identical diploid daughter cells, used for growth, repair, and asexual reproduction.

Meiosis

The type of cell division that produces four genetically unique haploid cells (gametes), used in sexual reproduction.

Cell Division

The process by which a parent cell divides into two or more daughter cells, including both mitosis and meiosis.

Chromosome Structure

Chromatin

The relaxed, thread

Chromosome

The condensed, visible structure of DNA and proteins that forms during cell division; humans have 46 chromosomes.

Chromatid

One of two identical copies of a replicated chromosome, joined at the centromere; sister chromatids separate during anaphase.

Cross

over

Centrioles

Paired cylindrical organelles found near the nucleus in animal cells that organize the spindle fibers during cell division.

Spindle Fibers

Microtubule structures that form during cell division to separate chromosomes; includes both kinetochore and polar fibers.

Kinetochore Fibers

Spindle fibers that attach to the kinetochore (protein structure) on chromosomes and pull chromatids or chromosomes apart.

Polar Fibers

Spindle fibers that extend from opposite poles and overlap at the cell's equator, helping to push the poles apart.

Reproduction Types

Sexual Reproduction

Reproduction involving the fusion of two gametes (egg and sperm) from different parents, producing genetically diverse offspring.

Asexual Reproduction

Reproduction involving a single parent that produces genetically identical offspring through mitosis.

Fission

A form of asexual reproduction where a single

Budding

A form of asexual reproduction where a new organism develops as an outgrowth from the parent organism.

Fertilization

The fusion of male and female gametes (sperm and egg) to form a diploid zygote.

Reproductive Cells

Gametes

Specialized reproductive cells (sperm and egg) that are haploid and fuse during fertilization.

Sperm

The male gamete, typically small and motile, containing genetic material from the male parent.

Ova (Egg)

The female gamete, typically larger and non

Haploid (1n)

Having one complete set of chromosomes, typical of gametes (23 chromosomes in humans).

Diploid (2n)

Having two complete sets of chromosomes, one from each parent (46 chromosomes in humans).

Development Terms

Embryos

Early developmental stages of multicellular organisms following fertilization, before recognizable features develop.

Blastocyst

An early

Differentiation

The process by which unspecialized cells become specialized into specific cell types with distinct structures and functions.

Stem cell

An unspecialized cell capable of self

Totipotent

Stem cells capable of differentiating into any cell type in the body, including placental tissue; only found in the earliest embryonic stages.

Pluripotent

Stem cells capable of differentiating into nearly any cell type in the body, but not placental tissue; found in the inner cell mass of blastocysts.

Multipotent

Stem cells capable of differentiating into a limited range of related cell types; found in specific tissues (like blood stem cells).

Cyclin

Regulatory proteins that control the progression of cells through the cell cycle by activating kinase enzymes.

Kinase

Enzymes that phosphorylate (add phosphate groups to) target proteins, often regulated by cyclins to control cell cycle progression.

Growth Factor

Signaling molecules that stimulate cell growth, division, and differentiation by binding to receptors on target cells.

Apoptosis

Programmed cell death, a controlled process where cells self

Cancer

A disease characterized by uncontrolled cell division and growth, resulting from mutations that disable normal cell cycle controls.

Tumor

An abnormal mass of tissue resulting from excessive cell division; can be benign (non