Plant Science – Key Vocabulary

A set of vocabulary flashcards summarising essential plant science terms from the lecture notes.

Life Cycle

Series of developmental stages an organism passes from birth to death.

Flowering Plant

Plant group that produces flowers, fruits and seeds for sexual reproduction.

Germination

Activation of a seed leading to growth of the embryonic plant.

Pollination

Transfer of pollen from anther to stigma enabling fertilisation.

Seed Dispersal

Movement of seeds away from parent plant to reduce competition.

Fruiting Plant

Plant that has developed fruit containing seeds after fertilisation.

Life-Cycle Trigger

Environmental condition that initiates a change to the next life-cycle stage.

Leaf

Primary photosynthetic organ; blade + petiole.

Photosynthesis

Process using light, CO₂ and water to produce glucose and O₂ via chlorophyll.

Respiration (Cellular)

Enzymatic breakdown of glucose with O₂ to produce CO₂, H₂O and ATP.

Transpiration

Loss of water vapour from leaves and stems, driving xylem water flow.

Palisade Mesophyll

Tightly packed chlorophyll-rich cells below upper epidermis; main photosynthesis site.

Spongy Mesophyll

Loosely packed leaf layer with air spaces for gas exchange.

Cuticle

Waxy leaf layer that reduces water loss.

Stoma (plural Stomata)

Pore in epidermis allowing gas exchange.

Guard Cell

Specialised epidermal cell controlling stomatal opening and closing.

Bundle-Sheath Cell

Leaf cell surrounding vascular bundle; involved in transport and protection.

Xylem

Dead, lignified vascular tissue transporting water and minerals root-to-leaf.

Phloem

Living vascular tissue transporting sugars and organic molecules leaf-to-sink.

Vascular Tissue

Plant tissue system composed of xylem and phloem for transport and support.

Ground Tissue

Plant tissue involved in photosynthesis, storage and support (cortex, pith, mesophyll).

Dermal Tissue

Outer protective covering of plants (epidermis, periderm).

Osmosis

Diffusion of water across a partially permeable membrane from high to low water potential.

Root Hair Cell

Extension of root epidermis providing large surface area for water absorption.

Anther

Flower structure that produces and releases pollen grains.

Filament

Slender stalk supporting anther, positioning it for pollen transfer.

Stigma

Sticky tip of pistil that captures pollen.

Style

Tube connecting stigma to ovary; pathway for pollen tubes.

Ovule

Structure within ovary containing female gamete; develops into seed after fertilisation.

Petal

Modified leaf, often coloured, that attracts pollinators.

Sepal

Outer floral leaf protecting bud before it opens.

Fertilisation (Plant)

Fusion of male and female gamete nuclei forming a zygote.

Cotyledon

Seed leaf; stores or absorbs nutrients for embryo.

Endosperm

Nutrient-rich tissue in seed that feeds developing embryo.

Monocot

Seed with one cotyledon; parallel-veined leaves; floral parts in threes.

Dicot

Seed with two cotyledons; net-veined leaves; floral parts in fours or fives.

Radicle

Embryonic root that emerges first during germination.

Hypocotyl

Embryonic stem section between radicle and cotyledons.

Epicotyl

Embryonic shoot above cotyledons; forms first true leaves.

Limiting Factor

Environmental component (light, CO₂, temperature) that restricts photosynthesis when scarce.

Carbon Cycle

Biogeochemical circulation of carbon via photosynthesis and respiration among biosphere, atmosphere and lithosphere.

Pressure-Flow Mechanism

Active phloem transport model where sugar loading creates pressure gradients driving sap movement.

Transpiration Stream

Continuous column of water pulled up xylem from roots to leaves by transpiration.

Turgor Pressure

Internal water pressure in plant cells providing rigidity.

Seed Coat (Testa)

Protective outer covering of a seed.