Kingdom Plantae radiant energy Photosynthesis Review Photosynthesis uses

Kingdom Plantae

radiant energy Photosynthesis Review • Photosynthesis uses radiant energy from the sun to fix carbon dioxide into GLUCOSE (sugar). CO 2 Photosynthesis glucose CO 2 O 2 • The captured radiant energy is stored within the bonds of the carbohydrate as chemical energy

One More Time

The Chemical Formula of Photosynthesis

Photosynthesis Evolved Under Water! CO 2 CO 2

Plants Biggest Challenges on Land • Water Loss

Plants Biggest Challenges on Land • Gas Exchange – CO 2 in / O 2 out – Must simultaneously minimize water loss

Solutions! - Waxy Cuticle - Roots - Stomata

Moss Leaf Cross Section

Vascular Plant Cross Section

Why Are Plants Important? Photosynthesis is the most important natural sink for CO 2 on Earth. This is critically important as part of the carbon cycle and can mitigate climate change. Plants cause ground water to evapourate from their leaves. This is called transpiration. It is an important part of the water cycle and contributes to the climate. Photosynthesis produces all of the oxygen gas on Earth Photosynthetic autotrophs, are at the base of every food chain on Earth. They produce the carbohydrates that all heterotrophs depend on for energy

Why Are Plants Important? Plants provide habitat for countless species Plants create microclimates and contribute to macroclimate Roots hold the soil in place, prevent erosion, minimize nutrient runoff and are critically important for the creation of new soil via decomposition.

Characteristics of Plants • All plants: – are multicellular eukaryotes – have cells with a cell wall and chloroplasts – are sessile – display an alternation of generations life cycle

Non-vascular Non-seed plants Vascular Seed plants Vascular Flowering Seed plants

Bryophytes

Key Terms • Antheridium – sperm producing structure • Archegonia – Egg producing structure which becomes the site of growth for the sporophyte • Sporangium – Site of meiosis in the sporophyte that produces haploid spores. • Rhizoid – Single celled root-like projections from the gametophyte

The Seed Plants: Gymnosperms and Angiosperms

Gymnosperms Pollen grains contain microscopic male gametophytes that produce sperm Pine cones contain structures called ovules. Each ovule holds a tiny female gametophyte.

Gymnosperms When an ovule is pollinated, it develops into a seed.

Pollination

The Seed

Gymnosperms are wind pollinated

Gymnosperms

Angiosperms

Parts Of The Flower

Some Angiosperms are wind pollinated, but most recruit pollinators