Origin of Plants Land plants came from Green Algae A plant is a multicellular autotroph in which the embryo develops within the female parent.plant

Challenges to Life on Land Resources –Algae - surrounding water –Plants - air and soil Roots –Anchor plant –Absorb water and Minerals

Shoots – Support, photosynthesis Leaves – Gas exchange, photosynthesis Vascular tissue – tube shape cells that branch through a plant – transport waters and minerals in plant

Maintaining Moisture Cuticle – Land plants’ waxy coating on the leaves and other aboveground parts of many plants, helping the plant body retain water. Stomata - are microscopic pores in the leaf's surface.

Algae Reproduction Surrounding water ensures that released gametes and offspring do not dry out. Also provides a means of dispersing the gametes and offspring to new locations.

Challenge Plants must keep from drying out in the air & must disperse. Adaptations: –produce their gametes in a "jacket" of protective cells. The protective jacket surrounds a moist chamber where gametes can develop without dehydrating. –Sperm reach the eggs by pollen grains, which are carried by wind or animals

Mosses (Bryophytes) Nonvascular Lack True leaves and roots –Have “roots” called rhizoids Need water to reproduce

Ferns Vascular Seedless (produce spores) Need water to reproduce Lignin

Gymnosperms Plant that bears seeds that are not enclosed in an ovary. Conifers – most common gymnosperms.

Picture 1: Why does the celery turn red? Picture 2: What are the red dots on the celery?

Land Plants ProblemSolution(s) cuticle Not in water – can’t disperse No water to hold up plant Need to be anchored Need to obtain water Stomata

Mosses (Bryophytes) Nonvascular Lack True leaves and roots –Have “roots” called rhizoids Need water to reproduce

Alternation of Generations Mosses have a sporophyte (spore producing) diploid stage and a gametophyte haploid stage.

antheridium archegonium Define: Alternation of Generations

Ferns (Pteridophytes) Vascular Seedless (produce spores) Need water to reproduce Lignin

Spore producing structure found on the underside of the leaf.

Gymnosperms Plant that bears seeds that are not enclosed in an ovary. Conifers – most common gymnosperms.

Gymnosperms Adaptations: –Small gametophyte (haploid) generation –Pollen –Seed – (embryo + food)

Pollen Pollen contains cells that develop into sperm.Pollen Wind carries pollen from male to female cones. Pollen allowed sperm to reach eggs in dry environments.

Why are mosses always small in size? How do the male gametes of mosses get from one plant to another to fertilize an egg? The ferns dominated the first forests on land. Describe two adaptations that allowed ferns to grow to tree size. Why are ferns still restricted to moist habitats for at least part of their life cycle? How are male gametes in gymnosperms transported? Describe how a seed is an important adaptation for land plants.

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Ferns The ferns dominated the first forests on land. Describe two adaptations that allowed ferns to grow to tree size. Why are ferns still restricted to moist habitats for at least part of their life cycle?

Gymnosperms How are male gametes in gymnosperms transported? Describe how a seed is an important adaptation for land plants.

Angiosperms Describe the important reproductive adaptations that characterize angiosperms.

Name:__________________ These anchor a plant into the ground. Where do the spores of ferns grow? What do the seeds of a gymnosperm lack?

Name:_____________ What adaptation maintains land plants moist? What do mosses lack? What do ferns need to reproduce?

Name:_____________ A gymnosperm is: Ferns can grow taller than mosses because they have: What is a seed:

Name:_________________ 2 problems with being a land plant: These are found in leaves and used for gas exchange: Mosses lack: