Introduction to Plants: Angiosperm Anatomy, Growth, and Physiology

Vocabulary flashcards covering plant structures, life cycles, growth types, tissues, hormones, nutrition, and transport mechanisms based on Kingdom Plantae lectures.

Angiosperms

Flowering plants belonging to Phylum Anthophyta that produce flowers, fruits, seeds, and vascular tissues, representing greater than $90\%$ of the plant kingdom.

Alternation of Generations

A life cycle characteristic of all plants involving an alternation between a diploid ($2N$) sporophyte plant form and a haploid ($1N$) gametophyte plant form.

Gametophyte

The multicellular haploid ($1N$) plant structure that produces gametes by mitosis and cytokinesis.

Sporophyte

The multicellular diploid ($2N$) plant structure that produces haploid spores (meispores) by meiosis.

Syngamy

The fertilization process resulting in the formation of a diploid ($2N$) zygote from two haploid gametes.

Indeterminate Plant Growth

An open-ended growth pattern where a plant continues to increase in size for as long as it remains alive.

Determinate Growth

A growth pattern that stops after a structure achieves a specific form or size, as seen in the production of flowers.

Meristem

A region of undifferentiated cells that produces new plant tissues through cell division.

Primary Growth

The elongation of plant organs (roots, stems, and leaves) driven by root apical meristems (RAM) and shoot apical meristems (SAM) in all plants.

Primary Xylem

A primary vascular tissue responsible for conducting water and dissolved minerals throughout the plant.

Primary Phloem

A primary vascular tissue responsible for conducting food, organic compounds, and solutes.

Parenchyma

The most abundant primary tissue type in plants, functioning in food and water storage and forming parts of the cortex and pith.

Collenchyma

A primary tissue located in the cortex that provides flexible protection and structural support to growing, elongating plant organs.

Sclerenchyma

A primary tissue located in the cortex that provides rigid protection and support to non-elongating plant organs.

Secondary Growth

The lateral expansion resulting in an increased diameter of roots and stems (never leaves) driven by lateral meristems.

Vascular Cambium

A ring of lateral meristem that produces secondary xylem (wood) to the inside and secondary phloem (inner bark) to the outside.

Cork Cambium

A lateral meristem producing rings of periderm (outer bark) that replace the epidermis and cortex for external protection.

Root Cortex

A cylinder of parenchyma cells enclosed by the root epidermis that is rich in starch and serves as a major food storage site.

Endodermis

The innermost cell layer of the root cortex responsible for the selective absorption of water and minerals.

Pericycle

A layer of meristematic cells enclosing the root vascular tissue that produces lateral or branch roots.

Internode

The section of a plant stem located between two adjacent nodes where elongation occurs.

Auxins

A class of growth-promoting hormones produced in shoot tips, seeds, fruits, leaves, and stems (not roots) that promote cell and shoot elongation while inhibiting lateral bud development.

Cytokinins

Growth-promoting plant hormones produced in seeds, fruits, and roots that promote cell division (cytokinesis) and lateral bud development while inhibiting leaf senescence.

Gibberellins

Growth-promoting plant hormones concentrated in seeds that promote stem elongation and stimulate the breakdown of food reserves during seed germination.

Abscisic Acid

A growth-inhibiting plant hormone found in seeds, mature leaves, and dormant buds that inhibits cell elongation and promotes leaf senescence.

Ethylene

A gaseous growth-inhibiting plant hormone produced by incomplete metabolism that promotes fruit ripening and leaf, fruit, and flower abscission.

Macronutrients

Essential plant mineral nutrients required in amounts of at least $1\,\text{g/kg}$ of dry plant mass.

Micronutrients

Essential plant mineral nutrients required in trace amounts equal to or less than $0.1\,\text{g/kg}$ of dry plant mass.

Transpiration

The evaporation of water from plant surfaces that creates a physical tension pull for long-distance bulk flow water transport.

Translocation

The energy-requiring transport of organic solutes, primarily sucrose, in the phloem from a source to a sink.

Double Fertilization

A reproductive process in angiosperms where one $1N$ sperm fertilizes the $1N$ egg to form a $2N$ zygote, and a second $1N$ sperm fuses with two $1N$ polar nuclei to form a $3N$ primary endosperm cell.

Stomatal Guard Cells

Specialized epidermal cells that regulate the opening and closing of stomata for gas exchange through changes in turgor pressure driven by potassium ($K^+$) flux.

Sieve-Tube Elements

Elongated phloem cells arranged end-to-end with sieve plates that lose their nuclei and cytoplasm at maturity to optimize bulk flow transport of phloem sap.