Plants Test

Characteristics Plantae

Eukaryotic

Multicellular

Autotrophic: photosynthesis

Cell wall: cellulose

Timeline

Green algae (multicellular): oldest ancestor of plants

• Charophyceans

◦ Lived in water

◦ Photosynthetic eukaryotes

◦ Most species are multicellular

Bryophytes (first true plants)

• Adaptation #1: cuticle

◦ Waxy coat on the outside of leaves to help with water retention

• Adaptation #2: stomata

◦ Pores in the leaf surface for gas exchange

Seedless vascular plants

• Adaptation #3: roots

◦ Absorption of water and nutrients

◦ Anchor

◦ Storage of energy

• Adaptation #4: vascular system

◦ Transport of nutrients and water

◦ Xylem: transports water up through the plant

◦ Phloem: transport mainly food through the plant (and some water)

• Adaptation #5: lignin

◦ Found in some cell walls

◦ Structure and support

Seeded vascular plants: gymnosperms

• Adaptation #6: seeds

◦ Plant embryo

• Adaptation #7: pollen

◦ Male reproductive gametophyte

◦ Transportable

Seeded vascular plants: angiosperms

• Adaptation #8: flowers

◦ Reproductive organ

Alternation of Generations plants alternate between a sporophyte form (2n) and a gametophyte form (n)

2n diploid

n haploid

Bryophytes

Nonvascular

No roots

Low to the ground

Live near water

Seedless Vascular

Have a vascular system

• Xylem: water transport

• Phloem: food transport

Low growing

Dependent on water

Seeded Vascular Plants - Gymnosperms

Translates to “naked seed”

Cone-bearing

Leaves are needle-like and waxy

Most are evergreen with needles lasting 2-4 years

Conifers, cycads, ginkgos, and gnetophytes

Seeded Vascular Plants - Angiosperms

Translates to “enclosed seed”

Seeds are found in fruit (ovary)

Most evolved and most common

Flowers: reproductive organ

Angiosperm Classification

Monocot

• One cotyledon (seed leaf)

• Parallel leaf veins

• Flower pars in multiples of 3

• Vascular tissue scattered

• Fibrous roots

Dicot

• Two cotyledons (seed leaf)

• Branched (netted) leaf veins

• Flower parts in multiples of 4 or 5

• Vascular tissues arranged in ring

• Taproot

Reproduction in Angiosperms (Flowers)

Male reproductive parts: stamen

• Anther

• Filament

Female reproductive parts: pistil

• Stigma

• Style

• Ovary

• Ovule

Petals: attract pollinators

Sepals: protect young flower

Flower to Fruit

Ovules (female gametophyte) are fertilized by pollen (male gametophyte) and turn into seeds

The ovary grows and fills with sugar (so animals will eat it)