Cell Biology, Differentiation, and the Cell Cycle

Comprehensive vocabulary flashcards covering plant cell organelles, DNA organization, phases of the eukaryotic cell cycle, levels of biological organization, stem cells, and early human embryonic development.

Nucleus

The organelle that controls the plant cell's activity and holds DNA.

Nucleolus

The cellular structure that makes the components used to build ribosomes, also known as ribosomal RNA (rRNA).

Cell membrane

The protective barrier that controls what enters and leaves the cell.

Rough ER

A region of the endoplasmic reticulum that folds and processes proteins.

Smooth ER

A region of the endoplasmic reticulum that makes lipids and helps with detoxification.

Endoplasmic Reticulum

A continuous membrane system composed of Rough ER, which folds and processes proteins, and Smooth ER, which makes lipids and aids detoxification.

Ribosomes

Cellular complexes that make proteins.

Golgi Apparatus

An organelle that modifies, sorts, and packages materials within the cell.

Mitochondria

Organelles that release usable energy from food.

Chloroplast

An organelle that uses sunlight to help make sugar in plant cells.

Cell Wall

A rigid outer layer that provides support and protection to the plant cell.

Chromosome

One long continuous thread of DNA consisting of thousands of genes and regulatory information (also known as a chromatid).

Gene

A section of DNA with instructions for making a protein, adhering to the principle that one gene equals one protein.

Homologous chromosomes

Pairs of chromosomes in normal body cells containing the same gene sequence, with one chromosome inherited from the biological mother and one from the biological father.

Sister chromatids

Identical copies of a duplicated chromosome formed during DNA replication and joined at the centromere.

Centromere

The specialized region of a chromosome where duplicated sister chromatids are held together.

Cell Cycle

A repeated pattern of growth, DNA duplication, and cell division that occurs in eukaryotic cells.

Purposes of the Cell Cycle

The two primary biological objectives of the cell cycle: growth and repair.

Interphase

The growth phase of the cell cycle comprising three parts ($G_1$, S, and $G_2$), resulting in a cell with 2 full sets of chromosomes and organelles.

$G_1$ phase

Gap 1 phase; the first part of interphase where the cell grows and makes proteins.

S phase

Synthesis phase; the stage of interphase where DNA replication occurs, doubling the number of chromosomes so the cell has 2 full sets.

$G_2$ phase

Gap 2 phase; the final stage of interphase characterized by more cell growth, duplication of organelles, and protein synthesis.

Mitosis

The phase of the cell cycle during which nuclear cell division occurs, progressing through prophase, prometaphase, metaphase, anaphase, and telophase.

Cytokinesis

The physical separation of the cytoplasm that starts at the end of mitosis.

Organism

One individual member of a species.

Organ System

A set of organs working together for a common function, such as the digestive system.

Organ

A set of tissues working together for a common function, such as the stomach.

Tissue

A group of cells working together for a common function, such as muscle tissue.

Cell

The most basic unit of life that possesses all the characteristics of life, such as a muscle cell.

Stem cells

Undifferentiated cells that can become differentiated into one or more types of specialized cells.

Embryonic stem cells

Stem cells that have never differentiated and possess the potential to become any cell type.

Adult stem cells

Cells found in adult bone marrow that are partially differentiated and can only become certain cell types.

Zygote

The single diploid cell resulting from the fertilization of an egg nucleus by a sperm nucleus.

Cleavage

The series of rapid mitotic cell divisions beginning around 30 hours after fertilization, progressing from the 2-cell stage to 4-cell and 8-cell stages.

Morula

An early embryonic stage consisting of a solid mass of cells reached approximately 72 hours after fertilization.

Blastocyst

The developmental embryonic stage formed at approximately 4 days post-fertilization.

Implanted Blastocyst

The embryonic stage that embeds into the uterine wall at 6 days after fertilization.