Angiosperm Life Cycle & Flower Anatomy, Modified Structures, Pollination, and Seed Adaptations, Labs

Sepals

Leaf-like structures protecting the flower bud.

Petals

Colorful floral organs attracting pollinators.

Stamens

Male flower parts: anther + filament.

Carpel (Pistil)

Female parts: stigma, style, ovary.

Ovule

Contains egg; becomes seed after fertilization.

Ovary

Becomes fruit after fertilization.

Double Fertilization

One sperm fertilizes egg (2n), another forms endosperm (3n).

Endosperm

Triploid tissue that nourishes embryo.

Directed Pollination Hypothesis

Flowers evolve traits to attract specific pollinators.

Pollination Mechanisms

Bees: blue/yellow; Birds: red, no scent; Wind: small, unscented.

Self-Incompatibility

Prevents self-fertilization via chemical recognition.

Dioecy

Separate male/female plants.

Dichogamy

Stamens and carpels mature at different times.

Modified Leaves

Tendrils (climbing), spines (defense), needles (water conservation), onion scales (storage).

Modified Stems

Rhizomes (underground), stolons (runners), tubers (storage), corms (vertical storage), prop roots (support).

Modified Roots

Pneumatophores (air), storage roots (carrot), contractile roots (pull down bulb).

Seed Formation (Monocot vs. Eudicot)

Monocot: 1 cotyledon, persistent endosperm; Eudicot: 2 cotyledons, absorb endosperm.

Seed Dispersal

Wind (dandelion), water (coconut), animals (fruits), explosion (jewelweed).

Seed Dormancy

Delay of germination until favorable conditions; broken by stratification/scarification.

Simple Fruit

From one ovary (peach).

Aggregate Fruit

From many carpels of one flower (strawberry).

Multiple Fruit

From multiple flowers (pineapple).

Accessory Fruit

Includes non-ovary tissues (apple).

Shannon Index

Measures species diversity considering richness & evenness.

Simpson’s Dominance Index

Measures dominance; higher = lower diversity.

Pielou’s Evenness

Measures how evenly species are represented.

Dermal Tissue

Outer protective covering (epidermis).

Ground Tissue

Includes parenchyma, collenchyma, sclerenchyma; photosynthesis and support.

Vascular Tissue

Xylem and phloem; water and nutrient transport.

Primary Growth

Increases length via apical meristem.

Secondary Growth

Increases width via vascular and cork cambium.

Tree Trunk Layers

Cork → Phloem → Cambium → Xylem (sapwood → heartwood).

Amoeba

Free-living protozoan using pseudopodia; reproduces by fission.

Physarum

Plasmodial slime mold; multinucleate mass that forms sporangia.

Phagocytosis

Engulfing food particles by cell membrane.

Pseudopodia

“False feet” used for movement and feeding.