Introduction to Cell Biology, Chromosomes, Cell Cycle, and Stem Cells

A set of vocabulary flashcards defining key cell biology, organelle, chromosome structure, cell division phase, and stem cell terminology from the lecture notes.

Germplasm theory

A theory proposed by Dr. Wiseman stating that germline cells are highly specialized cells developed specifically for passing genetic information from parents to offspring, rather than being constructed from parts of all other cells in the body.

Prokaryotes

Very small cells that lack membrane-bound organelles and typically possess a single chromosome.

Endoplasmic reticulum

A eukaryotic cell organelle where a large amount of protein synthesis occurs, specifically for proteins requiring heavy modification.

Golgi apparatus

An organelle described as the post office of the cell, responsible for packaging, marking, and transporting molecules being received or sent out from the cell.

Mitochondria

Energy-generating organelles containing their own unique genome inherited entirely from the mother's egg cell, featuring a folded interior membrane to maximize surface area for energy generation.

Chromosomes

Organized thread-like structures found in eukaryotic cells composed of chromatin that contain all of the cell's DNA.

Histones

Proteins consisting of histones 2a, 2b, 3, and 4 (two copies of each forming an interior ball) around which DNA wraps approximately $2.7$ times, held in place by histone 1 to prevent unwrapping.

30 nanometer fiber

A structure formed when the basic histone-DNA complexes wind around themselves, which then further wraps to form a chromatid.

Telomeres

Specially repeated nucleotide segments located at both ends of a chromosome that protect the rest of the DNA from being degraded during cell replication.

Apoptosis

Cellular suicide that is triggered when a cell's telomeres are completely degraded and no longer protect the DNA from being destroyed.

Karyotype

A graph or visual display showing human chromosomes arranged into $23$ pairs.

Diploid cells

Cells that contain two sets of chromosomes.

Haploid cells

Cells that contain only one set of chromosomes.

G0 phase

A non-dividing phase where a cell splits off from the main cell cycle after growing enough to perform its specific specialized function indefinitely without dividing.

G1/S checkpoint

A cell cycle checkpoint that verifies if the cell is large enough and has sufficient materials, nucleotides, and energy available to undergo DNA replication.

S phase

The synthesis phase of the cell cycle that takes up about a third of the cell's life cycle, focused exclusively on replicating DNA.

G2/M checkpoint

The major checkpoint driving mitosis where the cell verifies that DNA damage/mistakes are repaired and that the cell has sufficient size, water, nutrients, and energy to survive giving half its contents away.

Cytokinesis

The final step following telophase during which the cell membrane physically pinches apart, leaving two separate daughter cells.

Pluripotent stem cells

Stem cells that have the ability to turn on specific genes and differentiate into any type of cell in the body.

Multipotent stem cells

Stem cells capable of differentiating into a smaller, specific subset of specialized cell types (such as skeletal, cardiac, or smooth muscle) but unable to form unrelated cell types like neurons.

Induced pluripotent stem cells

Regular differentiated cells that have been chemically or genetically modified to reactivate pluripotent or multipotent stem cell genes.