1. KEY CONCEPT Plant life began in the water and became adapted to land.

2. Land plants evolved from green algae.
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. 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 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

5. 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.

6. True plants evolved through natural selection.

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

8. Stomata are tiny holes in the cuticle.
can open and close
allow air to move in and out

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

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

11. 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. A seed is a storage device for a plant embryo.
seed coats protect embryos from drying wind and sunlight
embryo develops when environment is favorable

13. Plants evolve with other organisms in their environment.
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
flowering plants and their animal pollinators

14. Plants have adaptations that prevent animals from eating them.
spines and thorns
defensive chemicals

15. KEY CONCEPT Plants can be classified into nine phyla.

16. Mosses and their relatives are seedless nonvascular plants.
Nonvascular plants grow close to the ground to absorb water and nutrients.
Seedless plants rely on free-standing water for reproduction.
Liverworts belong to phylum Hepatophyta.
often grow on wet rocks or in greenhouses
can be thallose or leafy

17. Hornworts belong to phylum Anthocerophyta.
found in tropical forests and along streams
flat, lobed body with little green “horns”

18. Mosses belong to phylum Bryophyta.
most common seedless nonvascular plants
sphagnum moss commonly used by humans as “peat”

19. Club mosses and ferns are seedless vascular plants.
A vascular system allows club mosses and ferns to grow higher off the ground.
Both need free-standing water for reproduction.
Club mosses belong to phylum Lycophyta.
not true mosses
oldest living group of vascular plants

20. Ferns and their relatives belong to phylum Pterophyta.
frond
fiddlehead
whisk ferns and horsetails are close relatives of ferns
ferns have large leaves called fronds

21. Seed plants include cone-bearing plants and flowering plants.
Seed plants have several advantages over their seedless ancestors.
can reproduce without free-standing water, via pollination
pollination occurs when pollen meets female plant parts
seeds nourish and protect plant embryo
seeds allow plants to disperse to new places

22. Gymnosperms do not have seeds enclosed in fruit.
most gymnosperms are cone-bearing and evergreen.
the cone is reproductive structure of most gymnosperms.
pollen is produced in male cones.
eggs are produced in female cones.
seeds develop on scales of female cones.

23. Cycads are gymnosperms in phylum Cycadophyta.
look like palm trees with large cones
grow in tropical areas

24. Ginkgos are gymnosperms in phylum Ginkgophyta.
only one species alive today, Ginkgo biloba
grown in gardens and used in urban landscaping

25. Conifers are gymnosperms in phylum Coniferophyta.
most common gymnosperms alive today
includes pines, spruce, cedar, fir, and juniper

26. Angiosperms have seeds enclosed in some type of fruit.
A flower is the reproductive structure of angiosperms.
A fruit is a mature ovary of a flower.
Angiosperms, or flowering plants, belong in phylum Anthophyta.

27. KEY CONCEPT The largest phylum in the plant kingdom is the flowering plants.

28. Flowering plants have unique adaptations that allow them to dominate in today’s world.
Flowers allow for efficient pollination.
animals feed on pollen or nectar
pollen is spread from plant to plant in process

29. Fruit allows for efficient seed dispersal.
Fruit is flower’s ripened ovary
Surrounds and protects seed(s)
Many forms, each function in seed dispersal

30. Botanists classify flowering plants into two groups based on seed type.
A cotyledon is an embryonic “seed leaf.”
Monocots have a single seed leaf.
leaf veins usually parallel
flower parts usually in multiples of 3
bundles of vascular tissue scattered in stem

31. Dicots have two seed leaves. Two cotyledons
leaf veins usually netlike, weblike
flower parts usually in multiples of 4 or 5
bundles of vascular tissue in rings in stem

32. Flowering plants are also categorized by stem type and lifespan.
Stem type can be woody or herbaceous.
Wood is a fibrous material made up of dead cells.
Wood has high concentrations of lignin and cellulose.
Woody stems are stiff.
Oak

33. Flowering plants are also categorized by stem type and lifespan.
Stem type can be woody or herbaceous.
Wood is a fibrous material made up of dead cells.
Wood has high concentrations of lignin and cellulose.
Woody stems are stiff.
Herbaceous plants do not produce wood.
Iris

34. There are three types of plant life spans.
Annuals mature from seed, flower, and die in one year.
Wheat

35. There are three types of plant life spans.
Annuals mature from seed, flower, and die in one year.
Biennials take two years to compete life cycle.
Foxglove

36. There are three types of plant life spans.
Annuals mature from seed, flower, and die in one year.
Biennials take two years to compete life cycle.
Perennials live more than two years.
Big bluestem

37. KEY CONCEPT Humans rely on plants in many ways.

38. Agriculture provides stable food supplies for people in permanent settlements.
Botany is the study of plants.
Ethnobotany explores how people in different cultures use plants.

39. People started planting for harvest about 10,000 years ago.
wild species “tamed” through artificial selection
farming requires people to stay in one place
farming helped more socially complex centers develop
Teosinte

40. Plant products are important economic resources.
Plant products have been traded for thousands of years.
spices commonly used as currency in Middle Ages
spurred seafaring expeditions in 1400s and 1500s

41. Plant products contribute to economy on a global scale today.
grains, coffee, sugar, cotton, forest products
billions of dollars of plant products traded each year

42. Plant compounds are essential to modern medicine.
Pharmacology is the study of drugs and their effects on the body.
Many drugs are derived from plants.
Salicin from willow trees is used in aspirin.
Alkaloids are potent plant chemicals that contain nitrogen.
Alkaloids such as taxol have anti-cancer properties.

43. Some medical research focuses on properties of plant compounds.
studies plants used medicinally in traditional cultures
develop synthetic drugs based on plant compounds