Main Ideas Land plants evolved from green algae

1. Main Ideas • Land plants evolved from green algae • Plants have adaptations that allow them to live on land. • Plants evolve with other organisms in their environment.

2. Land plants evolved from green algae. 1. Plants and green algae have many common traits. • both are photosynthetic eukaryotes • both have the same types of chlorophyll • both use starch as a storage product • both have cell walls with cellulose

3. 2. Genetic analysis points to the common ancestor of all plants. • extinct green algae species in class Charophyceae • modern charophyceans common in lakes and ponds

4. Important plant characteristics that likely originated in charophyceans. • Multicellular body allowing for specialization of cells and tissues • Cell division that allows for chemical communication between cells • Reproduction involving sperm swimming to egg

6. True plants evolved through natural selection. • Ancestral charophyceans lived in areas of shallow water. • Those that could survive longer dry periods were favored. • First true plants probably grew at edges of water. • True plants have embryos that develop while attached to female parent (seeds!!!)

7. Challenges of living on land have selected for certain plant adaptations. Plants have adaptations that allow them to live on land. • 1. A cuticleallows plants to retain moisture. • waxy, waterproof layer • holds moisture in

8. 2. Stomataare tiny holes in the cuticle. stoma • can open and close • allow air to move in and out

9. 3. A vascular system allows resources to move to different parts of the plant. water and mineral nutrients sugars • collection of specialized tissues • brings water and mineral nutrients up from roots • disperses sugars from the leaves • allows plants to grow higher off the ground

10. 4. Lignin allows plants to grow upright. lignin plant cells • hardens cell walls of some vascular tissues • provides stiffness to stems

11. 5. Pollen grains allow for reproduction without free-standing water. • pollen grains contain a cell that divides to form sperm • pollen can be carried by wind or animals to female structures

12. 6. Seeds are storage devices for a plant embryo. • seed coats protect embryos from drying wind and sunlight • embryo develops when environment is favorable • (moisture, temperature, etc just right)

13. Plants and other organisms can share a mutualistic relationship. a mutualism is an interaction in which two species benefit plant roots and certain fungi and bacteria Ex: Mycorrhizal fungi help plant roots absorb nutrients and fight off harmful predators flowering plants and their pollinators Plants evolve with other organisms in their environment.

14. Plants also have plant-herbivore interactions A plant or portions of the plant are consumed by another organism Bacteria and fungi can cause disease as they feed on plant tissue Browsers and grazers, insects and animals that eat seeds are considered herbivores. Some herbivores consume entire plants, or enough to kill them. Others only eat a portion of the plant, and so the plant can recover. Plants evolve with other organisms in their environment.

15. Plants have adaptations that prevent animals from eating them. Defensive chemicals Spines and thorns Monarch butterfly caterpillars eat milkweed and incorporate the glycosides produced by the plant in their own tissues, making them poisonous to predators.

16. Plants also have parasites Parasite and its host evolve together Parasite adapts to its environment by living in and using the host in ways that harm it. Bacteria, viruses, and fungi have not spared the plants as hosts Vascular plants that parasitize other vascular plants Insects Plants evolve with other organisms in their environment. Dwarf Mistletoe (growing on the branch of a Jeffrey Pine…The ripe berries are ready to explode and forcibly eject their sticky seeds.

17. Sea Oxeye Daisy (Borrichia frutescens) • Found in salt-water areas in Alabama, Florida, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Texas and Virginia • Gall midge fly (Asphondyliaborrichiae) is a parasite of Sea Oxeye Daisies- induces galls into the stems

18. Gall Midge Gall Formation on Sea Oxeye Daisy • Female gall midge deposits her eggs into the stem of Sea Oxeye Daisy • A gall forms and the fungal mycelium grows to line the inside of the gall. • When the egg hatches the developing larva feeds upon the fungus. • Gall formation + fungus= often lethal for the plant

19. Effects of galls on Sea Oxeye Daisies • Destruction of tissue in this part of the plant can stop its growth, prevent its flowering, and kill the whole stem • Usually one gall per plant, but each may have several chambers • Each gall contains a fly larva (which feeds on fungus growing inside the gall), then pupates and emerges as an adult. • The galls also contain several species of wasps, which are parasitoids on the fly.

20. Midge flies have their own parasite • 4 different species of parasitic wasps • Pierce galls with gall midges larvae inside and kills larvae • Lay eggs in dead fly larvae

21. Lab: Sea Oxeye Daisy Gall Dissection • To be written in lab journal as a formal lab write-up. • You will dissect 3 galls/group to observe fly larvae and/or parasitic wasps. • You will dissect out each gall under the microscope using a scalpel and forceps. • After dissection, you will draw what you see under the microscope. • Your data should also include how many chambers were in each gall.