re/plantae/ KINGDOM PLANTAE

Evolution There are over 280,000 species of plants on Earth. They are estimated to have evolved from green algae million years ago. The fist plants to evolve where similar to mosses and reproduced using spores, an adaptation to being on land. Over time, selection favored plants that could tolerate dry land which lead to seed evolution. Plants with true seeds evolved around million years ago. As selection began to favor plants with seeds a new adaptation was seen, flowers and fruits, around million years ago. Some flowering plants have adapted to live back in the aquatic environment from wince they first evolved (aquatic angiosperms)

Life Cycle Plants have a life cycle that consists of alternating phases. “Alternating of Generations” Sporophyte (2N) Gametophyte (1N) In seeded plants the sporophyte is the most dominant form. The gametophytes are structures on the sporophyte. (Ex. flowers)

Classification Botany is the study of plants. In botany, plants are classified into divisions instead of phyla. The divisions are based on three factors: Vascularization Seed Production Flowering

Embryophyta LAND PLANTS

Embry0phytes In general, land plants are: autotrophs (photoautotrophs) reproduce asexually and sexually multicellular Phototropic- grow toward light cell walls made of cellulose The phyla of kingdom Plantae are divided into four major divisions… Bryophyta Pteridophyta Gymnosperms Angiosperms

Bryophyta (the mosses) Non Vascular Reproduce with Spores Includes the mosses, liverworts, and hornworts

Tracheophytes VASCULAR PLANTS

Tracheophytes- Vascular plants Tracheophytes are land plants that have vascular tissue. They include all plants except for bryophytes. Vascular tissue forms vessels that carry water, plant products and nutrients up and down the plant. Xylem: Vessels that carry water and soil nutrients from the roots to the plant parts. (flows up!) They are always interior to the phloem. Phloem: Vessels that carry food (products of photosynthesis) form the leaves to the rest of the plant (flows down!) They are always exterior to the xylem. This allows them to grow taller/larger than non-vascular plants such as the bryophytes.

Pteridophyta (the ferns) Vascular Reproduce with Spores Clubmosses, horsetails, and ferns.

Spermatophytes SEED PRODUCING PLANTS

Spermatophytes Spermatophytes are plants that reproduce with seeds instead of spores. larger than spores. multicellular. produced by the fertilized gametes (ovules and pollen) of plants. germinate more easily than spores because they do not require much moisture. spread by the plant itself, animals, or the wind. can be naked or enclosed in the ovary of a flower/fruit. Two groups of seed producing plants angiosperms (enclosed) and gymnosperms (naked). 02/ oldest-seeds-regenerated-plants- science/ 02/ oldest-seeds-regenerated-plants- science/

Gymnosperms (conifers) Vascular Sporophyte dominant life-cycle Tend to be large and woody Reproduce with Seeds Includes conifers, cycads, Ginkgos, and Gnetales

Magnoliophyta FLOWERING PLANTS

Flowers Stamen= male reproductive organ (pollen is released here) Pistal= female reproductive organ (ovule is housed here)

Angiosperms (flowering plants) Became the most dominant plant type about million years ago. The largest and most diverse division of plants. Come in two basic types: monocots and dicots Flowers are found on specialized stems called inflorescence. Autotrophic Vascular Flowering/fruiting Seed Reproduction

Heterotrophic Angiosperms Carnivorous/insectivorous Plants: Heterotrophic adaptation increases the growth and reproduction of the plant- most can grow strictly from autotrophic plant products but grow and reproduce better when heterotrophic. They capture prey and externally digest it, then absorb the nutrients. Parasitic and Saprophytic plants: Heterotrophic- some are still slightly autotrophic but some lack cholorphyll completely and are strictly heterotrophic Steal food, nutrients, and water from other plants Usually do not have roots Chemotrophic

Mimicry in Plants There are many types of mimicry in the plant kingdom, most involve attracting a pollinator or avoiding a predator. Plants have evolved that mimic the scents and appearances of other plants and animals. Mimicry gives them reproductive advantage. Those that closely resemble the characteristic that is being mimicked will survive and reproduce better than those that do not.