Plants

Plant Characteristics– Many celled– Cell walls– Chlorophyll– cuticle

Evolution and Classification

Evolved from green algae First plants were small and lived close to

water– Non vascular: no specialized tissues to

transport water liverworts MossesVascular plants: have tissues that can transport water

(tubelike structures) / successfully grow on land Can produce Seeds and flower – important

adaptations Examples are conebearing trees and flowering plants

Chemistry in Plants Photosynthesis:

– Light (absorbed by chlorophyll) + water (roots) + CO2 (enters through stomates) makes glucose + water + oxygen

Nonflowering Plants Ex.’s mosses, ferns, horsetails, cone-

bearing trees

Life Cycle of Nonflowering Plant:Sporophyte: Non sexual stage produces spore

Produces spores

Gametophyte: sexual stage / produces egg and sperm

Produces sperm cells

fertilization

Bryophytes Mosses:attaches to the ground by

small rhizoids (root-like structures).No true roots– Water travels via osmosis

Liverworts: found in wet areas of a forest or bog.– Flat leaflike structures– rhizoids

Nonflowering Vascular Plants

Can grow tall because of tubelike vascular tissues to carry food and water

Can grow almost anywhere on land

Ferns Grow in forests Warm tropical or seasonal areas Small True roots, stems (usually

underground), and leaves (fronds) Contain vascular tissue Sporophyte (larger and lives longer)

and gametophyte lifecycles

Horsetails Life cycle similar to fern

Club Mosses

Have vascular tissue / are not mosses / tropical areas

Gymnosperms Nonflowering vascular plants that

produce seeds Conebearing trees (pine and redwood) Seed is for protecting and nourishing

embryo Don’t need water for sperm to swim in

to get to egg instead travel as dustlike particles in the air called Pollen

Groups of Gymnosperms Conifers (needle shaped leaves and seeds

produced in cones) Cycads (remains of ancient forests) Gnetophytes (long straplike leaves and

bears clusters of small cones on short stalks)

Ginkgo (fan-shaped leaves and fleshy cones and leaves fall from tree in autumn)

conifers

CycadsGnetophytes

Ginkgo

Characteristics of Flowering Plants

Angiosperms – produce seeds within a flower

Evolved from gymnosperms Have vascular tissue and produce

pollen Flowers contain sex organs

– Male sex organ makes pollen– Female sex organ makes egg cells

Adaptations that help plants reproduce

Colorful and complex flowers – depend on insects, bats or hummingbirds to carry pollen. Characteristics that attract pollen carriers:– Shape – Scent– Color

Most flowers are grouped together in clusters some have only 1 single flower

Angiosperm Classification 2 groups based on number of seed

cotyledons (leaflike parts of the plant embryo inside the seed)

1. Monocot:– 1 cotyledon– Parallel vein pattern– Scattered bundles of vascular tissue in

stem– Fibrous roots– Ex. Grasses, corn, tulips, palms

Angiosperm Classification Dicots

– Two cotyledons– Leaves have branching pattern of veins– Bundles of vascular tissue are arranged

in a ring.– Large thick taproot– Ex. Oak, maple, fruit trees– Tomato plants, pea plants, sunflowers

Vascular Plant Systems Xylem – a set of linked cells where

water and minerals travel (from the root to the shoot system)– Water is used in photosynthesis– Water is lost through stomates =

transpiration Phloem – transports glucose from

leaves to other parts of plant

Root System Functions:

– Support and anchor plant– Absorb water and minerals from soil– Store glucose in the form of starch

Types:– Fibrous root– Tap root