Plant Reproduction and Life Cycle Overview

Flower

Reproductive structure producing gametes and seeds.

Gametes

Haploid cells involved in sexual reproduction.

Seeds

Embryo with nutrient stores in a protective coat.

Fruits

Develop from flowers, containing seeds.

Sexual Reproduction

Involves meiosis and fertilization for offspring.

Meiosis

Nuclear division reducing chromosome number by half.

Fertilization

Fusion of haploid gametes forming a diploid zygote.

Sporophyte

Diploid phase of land plant life cycle.

Gametophyte

Haploid phase of land plant life cycle.

Alternation of Generations

Life cycle with alternating diploid and haploid forms.

Spores

Haploid cells growing into adult individuals.

Sporangia

Structures where meiosis produces haploid spores.

Mitosis

Cell division producing genetically identical cells.

Zygote

Diploid cell formed from fertilized gametes.

Asexual Reproduction

Production of clones without fertilization.

Clones

Genetically identical copies of the parent plant.

Vegetative Reproduction

Cloning new plants from adult parts.

Runners

Horizontal stems producing new plants at nodes.

Rhizomes

Underground stems that produce new shoots.

Apomixis

Asexual embryo development in ovule.

Photoperiodism

Plant response based on day and night lengths.

Photoperiod

Relative lengths of day and night.

Floral Meristem

Apical meristem developing into flower structures.

Long-day plants

Bloom in midsummer with longest days.

Short-day plants

Bloom in spring or fall with shortest days.

Day-neutral plants

Flower regardless of photoperiod.

Phytochrome

Plant pigment involved in photoperiod response.

CONSTANS (CO)

Gene expression triggered by clock proteins.

Florigen

Hypothetical flowering hormone from leaves.

Calyx

Group of sepals protecting flower buds.

Corolla

Group of petals attracting pollinators.

Stamens

Male reproductive structures producing pollen.

Anthers

Pollen-producing organs on stamens.

Filament

Stalk supporting the anther in stamens.

Carpels

Female reproductive structures producing ovules.

Stigma

Moist tip of carpel receiving pollen.

Style

Slender stalk connecting stigma and ovary.

Ovary

Base of carpel containing ovules.

Perfect flowers

Contain both stamens and carpels.

Imperfect flowers

Contain either stamens or carpels only.

Monoecious plants

Have both stamen and carpel flowers.

Dioecious plants

Have either stamen or carpel flowers.

Megasporocyte

Diploid cell dividing to form megaspores.

Embryo sac

Multicellular haploid gametophyte from megaspore.

Micropyle

Opening to the ovule for pollen entry.

Haploid nuclei

Nuclei in embryo sac segregating during development.

Ovules

Structures in ovary containing female gametophytes.

Microsporangia

Structures in anthers containing diploid microsporocytes.

Microsporocytes

Diploid cells that undergo meiosis to form microspores.

Microspores

Haploid cells produced from microsporocytes via meiosis.

Pollen Grain

Haploid, immature male gametophyte with two nuclei.

Male Gametophyte

Develops from microspores, produces sperm after maturation.

Generative Cell

Cell in male gametophyte that produces sperm cells.

Tube Cell

Larger cell in pollen grain aiding in fertilization.

Pollination

Transfer of pollen from anther to stigma.

Fertilization

Union of sperm and egg forming a diploid zygote.

Self-fertilization

Sperm and egg from the same individual combine.

Outcrossing

Sperm and egg from different individuals combine.

Cross-pollination

Pollen transfer between different individuals.

Inbreeding Depression

Reduced biological fitness from mating between closely related individuals.

Temporal Avoidance

Male and female gametophytes mature at different times.

Spatial Avoidance

Physical separation of anthers and stigma in flowers.

Molecular Matching

Blocking pollination if pollen and stigma proteins match.

Mutualism

Mutually beneficial relationship between pollinators and plants.

Pollination Syndromes

Correlations between flower structure and pollinator traits.

Coevolution

Adaptation of flowers and pollinators enhancing pollination efficiency.

Wind-pollinated Species

Produce many pollen grains, rely on wind for pollination.

Animal-pollinated Species

Make fewer pollen grains, attract animals for pollination.

Insect Pollination

Enhances sexual reproduction efficiency and species formation.

Dioecious Species

Plants with separate male and female individuals.

Alpine skypilot

Plant with distinct flower traits based on habitat.

Speciation

Formation of new species through evolutionary processes.

Gene flow

Transfer of genetic material between populations.

Pollination

Transfer of pollen from male to female reproductive structures.

Insect pollinators

Insects that facilitate pollination by visiting flowers.

Bee pollination

Bees prefer yellow or blue flowers with nectar.

Butterfly pollination

Flowers visited by butterflies have flat landing platforms.

Moth pollination

Moth-pollinated flowers are often white and heavily scented.

Bird pollination

Birds prefer flowers with high nectar and red color.

Wind pollination

Pollination method using wind, often odorless flowers.

Fertilization

Fusion of sperm and egg to form a zygote.

Double fertilization

Two fertilization events in angiosperms producing zygote and endosperm.

Primary endosperm nucleus

Triploid cell formed during double fertilization.

Endosperm

Nutrient-storing tissue for developing embryo.

Seed development

Process of seed maturation after fertilization.

Seed coat

Protective outer layer surrounding the seed.

Mature seed

Contains embryo, endosperm, and seed coat.

Embryogenesis

Development process from zygote to multicellular embryo.

Pollen tube

Structure that delivers sperm to the ovule.

Sporophyte

Diploid phase in the plant life cycle.

Ovule

Structure that develops into a seed after fertilization.

Fruit

Mature ovary enclosing seeds for protection.

Nectaries

Flower parts that produce nectar to attract pollinators.

Basal Cell

Divides to form root tip and suspensor.

Suspensor

Transports nutrients from parent to embryo.

Terminal Cell

Forms cell mass for embryo development.

Protoderm

Exterior layer forming the plant's epidermis.

Ground Meristem

Forms ground tissue inside protoderm.

Procambium

Develops into vascular tissue in embryo.

Cotyledons

Seed leaves that store nutrients for seedlings.