Cellular Reproduction (Mitosis)

Flashcards covering key vocabulary terms related to cellular reproduction, mitosis, DNA, chromosomes, the cell cycle, and cell division processes in both prokaryotic and eukaryotic cells, based on lecture notes from Chapter 9.

Cell Division

The process by which a parent cell divides into two daughter cells, essential for growth, development, and repair.

DNA (Deoxyribonucleic Acid)

The hereditary information of all living cells, composed of nucleotides and packaged into chromosomes, forming a double helix.

Chromosomes

Structures containing a double helix of DNA plus proteins that organize DNA's 3-dimensional structure and regulate its use.

Genes

Units of inheritance, segments of chromosomal DNA ranging from a few hundred to several thousand nucleotides, spelling out instructions for making cell proteins.

Cell Cycle

The repeating pattern of growth and division that daughter cells formed by cell division may undergo.

Differentiation

The process by which daughter cells become specialized for specific functions (e.g., muscle cells for contraction, white blood cells for fighting infections).

Stem Cells

Cells characterized by self-renewal (capacity to divide) and potency (daughter cells can differentiate into specialized cell types).

Self-renewal

The capacity of stem cells to retain the ability to divide, sometimes for the entire life of an organism.

Potency

The characteristic of dividing stem cells to produce daughter cells that can differentiate into a variety of specialized cell types.

Meristem Cells

Stem cells found in plants, typically in the growing tips of roots, stems, and branches.

Differentiated Cells Capable of Dividing

Cells that can divide, but their daughter cells typically differentiate into only one or two specific cell types (e.g., liver cells).

Permanently Differentiated Cells

Cells that differentiate and never divide again (e.g., human red blood cells, most heart and brain cells).

Sexual Reproduction

A form of reproduction where offspring are produced by the fusion of gametes (sperm and eggs), involving meiotic cell division.

Asexual Reproduction

A form of reproduction where offspring are formed from a single parent without sperm fertilizing eggs, producing genetically identical offspring.

Prokaryotic Fission (Binary Fission)

The process of cell division in prokaryotic cells, involving DNA replication of a single circular chromosome followed by cell division.

Prokaryotic Cell Cycle

A relatively long period of growth in prokaryotic cells, during which the cell replicates DNA, followed by prokaryotic fission.

Histones

Proteins around which eukaryotic DNA is wrapped to condense it and reduce its length.

Telomeres

Protective caps at each end of a eukaryotic chromosome that prevent gene loss during replication.

Centromere

A middle area of a eukaryotic chromosome that temporarily holds two daughter DNA double helices together after DNA replication and serves as an attachment site for microtubules during cell division.

Eukaryotic Cell Cycle

Divided into two main phases: Interphase and Mitotic Cell Division, involving growth and DNA replication before division.

Interphase

The period between cell divisions in eukaryotic cells, sub-divided into G1, S, and G2 phases.

G1 Phase

The first growth phase during interphase, where the cell grows and differentiates.

S Phase (DNA Synthesis)

The phase during interphase when the cell's chromosomes are duplicated.

G2 Phase

The second growth phase during interphase, where the cell grows more and synthesizes proteins needed for cell division.

Mitotic Cell Division

Consists of mitosis (division of the nucleus) and cytokinesis (division of the cytoplasm), producing two daughter cells physically similar and genetically identical to each other and the parent cell.

Mitosis

The division of the nucleus during mitotic cell division, producing two daughter cell nuclei.

Cytokinesis

The division of the cytoplasm during mitotic cell division, placing half the cytoplasm, half the organelles, and one newly formed nucleus into each daughter cell.

Sister Chromatids

Two identical DNA double helices (and associated proteins) that make up a duplicated chromosome, attached to each other at the centromere.

Spindle

A structure composed of spindle microtubules that forms during mitosis and plays a crucial role in moving chromosomes.

Centrioles

Microtubule-containing structures in animal cells from which spindle microtubules originate; not present in plants, fungi or many algae.

Kinetochore

A protein-containing structure located at the centromere of each sister chromatid, serving as an attachment point for spindle microtubules.

Prophase

The first stage of mitosis where chromosomes condense, the nuclear envelope breaks down, the nucleolus disappears, and the spindle begins to form and capture chromosomes.

Metaphase

The stage of mitosis where kinetochore microtubules line up the chromosomes at the cell's equator.

Anaphase

The stage of mitosis where sister chromatids separate and move to opposite poles of the cell, becoming independent chromosomes.

Telophase

The final stage of mitosis where one set of chromosomes reaches each pole, decondenses, nuclear envelopes reform, nucleoli reappear, and spindle microtubules disappear.

Cell Plate

A structure formed in plant cell cytokinesis by the fusion of carbohydrate-filled vesicles from the Golgi apparatus along the cell's equator, eventually becoming a new cell wall.

Growth Factors

Molecules that many cells in the body release to signal the need for cell division.

Cell Cycle Checkpoints

Points in the eukaryotic cell cycle where proteins determine if a cell has successfully completed a specific phase and is ready to proceed.

Cyclins and Cdks (Cyclin-dependent kinases)

Proteins that regulate cell cycle checkpoints, stopping the cell cycle until defects are repaired.