Exam 3 Review: Plant Tissues, Cell Cycle & Mitosis, Meiosis, and Cell Regulation

Vocabulary practice flashcards covering plant anatomy and tissues, cell cycle phases, mitosis stages, meiosis, and cell cycle regulation.

Root System

The plant organ system responsible for absorbing water and minerals from the soil and storing carbohydrates, which provides shoots with water and essential minerals.

Shoot System

The above-ground plant organ system that produces sugars via photosynthesis using $\text{CO}_2$ and light energy to supply the root system.

Lateral Roots

Roots that branch off from a primary root and serve as the primary site where water absorption occurs.

Fibrous Root System

A root system characterized by a network of smaller roots that are all approximately the same size.

Taproot System

A root system featuring one large main primary root that gives rise to smaller lateral roots.

Node

The specific point on a plant stem where a leaf attaches.

Axillary Bud

The structure located on a plant stem from which a flower cluster or lateral branch can emerge.

Leaves

Plant organs whose functions include photosynthesis and dissipating excess heat.

Periderm

The protective dermal tissue layer that replaces the epidermis in woody plants.

Ground Tissue

Plant tissue responsible for storing sugars and carbohydrates; differentiated into an inner pith and an outer cortex.

Pith

The innermost region of ground tissue located internal to the vascular tissue in a plant stem or root.

Cortex

The outermost region of ground tissue located external to the vascular tissue.

Parenchyma Cells

Ground tissue cells that can differentiate into other cell types and function in storing sugar and carbohydrates in root tissue.

Collenchyma Cells

Living support cells found in young plant tissues that are characterized by cell walls of uneven thickness.

Sclerenchyma Cells

Dead support cells found in older, mature plant tissues that possess huge, thick, swollen cell walls.

Vessel Elements

Water-conducting cells of xylem that align end-to-end and contain small perforations to facilitate water flow.

Tracheids

Elongated, water-conducting cells that, together with vessel elements, make up the xylem in vascular tissue.

Phloem

Vascular tissue specialized for transporting sugars, consisting of sieve tube elements and companion cells.

Chromatin

The complex of DNA wrapped around structural proteins within the eukaryotic nucleus.

Chromosome Condensation

The tight coiling of chromatin that occurs during mitosis (prophase through telophase) to make moving DNA around easier.

Chromosome Decondensation

The uncoiling of chromosomes during interphase to allow cellular machinery access to genes for protein synthesis.

Sister Chromatids

A pair of identical copies of a replicated chromosome joined together before division.

$\text{G}_1$ Phase

The first gap phase of interphase in which the cell grows to its adult or mature stage, producing cytoplasm and organelles.

$\text{S}$ Phase

The synthesis phase of the cell cycle where the cell's genome/DNA and centrosomes/centrioles are duplicated.

$\text{G}_2$ Phase

The final stage of interphase where organelles are duplicated and all enzymes and proteins needed for mitosis are synthesized.

$\text{M}$ Phase

The phase of the cell cycle comprising both nuclear division (mitosis) and cytoplasmic division (cytokinesis).

Prophase (Mitosis)

The first phase of mitosis during which chromatin condenses into distinct chromosomes and the mitotic spindle begins to form.

Prometaphase (Mitosis)

The mitotic phase characterized by spindle microtubules making physical contact with sister chromatids at their kinetochores.

Metaphase (Mitosis)

The stage of mitosis where sister chromatids align along the middle (metaphase plate) of the cell.

Anaphase (Mitosis)

The mitotic stage during which sister chromatids separate and are pulled toward opposite poles of the cell.

Telophase (Mitosis)

The final stage of mitosis during which chromosomes arrive at the poles, decondense, and nuclear envelopes reform.

Cell Plate

A structure that forms during cytokinesis in dividing plant cells, developing into a separating cell wall between the daughter cells.

Contractile Ring

A ring of actin and myosin filaments that constricts during cytokinesis in animal/human cells, creating a visible cleavage furrow.

Cyclin-Dependent Kinase (Cdk)

A protein kinase that binds to cyclin and activates target enzymes or complexes (such as MPF) by transferring a phosphate group to them.

Human Somatic Cell

Any biological body cell of a human, which contains a total of $46$ chromosomes ($23$ pairs) and is diploid.

Autosomes

Non-sex chromosomes, of which humans have $22$ homologous pairs (a total of $44$ autosomes).

Gametes

Haploid sex cells—specifically sperm and eggs (ovules)—that contain half the genetic complement of somatic cells.

Fertilization

The union of two haploid gametes that produces a single diploid cell known as a zygote.

Meiosis

A two-round specialized cell division that reduces chromosome number to produce $4$ genetically distinct haploid gametes from one diploid cell.

Prophase I (Meiosis)

The stage of Meiosis I characterized by homologous chromosome pairing into tetrads and genetic exchange via crossing over.

Metaphase I (Meiosis)

The stage of Meiosis I where homologous chromosome pairs (tetrads) align along the center of the cell.

Anaphase II (Meiosis)

The stage in Meiosis II where sister chromatids separate and move toward opposite poles, directly mirroring mitotic anaphase.

Prophase II (Meiosis)

The stage of Meiosis II during which the nuclear envelope breaks down again in each haploid cell without prior DNA replication.

Density-Dependent Inhibition

A regulatory mechanism in normal tissue culture where crowded cells stop dividing once they contact one another; ignored by cancer cells.

Vascular Endothelial Growth Factor (VEGF)

A signaling protein secreted by cancer cells that stimulates nearby blood vessels to grow toward the tumor to supply it with nutrients.