Evolution of Angiosperms

1. Evolution of Angiosperms Chapter 20 Archaefructussinensis

2. Rafflesiaarnoldii True or False • Flowers are the reproductive structures of angiosperms. • Flowers are determinate shoots that bears sporophylls.

3. Evolutionary Trends Among Flowers • Flowers have gone from many indefinite parts to having fewer parts that are definite in number. • Floral whorls have reduced over time. • Floral parts have become fused. • Floral axes have become shortened. • Carpels have gone from leaflike and incompletely closed to pistil-shaped and sealed. • Ovaries have gone from superior to inferior. • Perianths have gone from having indistinct sepals and petals to having a distinct calyx and corolla. • Flowers have gone from radial (actinomorphic) to bilateral (zygomorphic) symmetry.

4. Which of the following is not involved in flower pollination? • A) bees • B) bats • C) beetles • D) toads named Mel • E) land mammals, i.e. mice • F) birds True or False • Floral evolution was and still is driven by animals.

5. Floral Evolution • Flowers and insects have coevolved. • Coevolution- the simultaneous evolution of adaptations in 2 or more interacting populations. • Insect pollination is more efficient than passive pollination. • Beetles, flies, bees. • Bees are the most important group of visiting insects.

6. Bird and bat-pollinated flowers • Produce copious nectar. • Usually bright red and yellow in color. • Birds have a good sense of color. • Flowers usually have very little odor. • Smell not developed in birds.

7. Flavonoids • Water soluble phenolic compounds with two six-carbon rings linked by a three-carbon unit. • Occur in the vacuole of plant cells. • The most important pigments in floral coloration are the anthocyanins (red, violet, and blue) and the flavonols.

9. Wind pollinated flowers do not produce nectar.

10. Asteraceae and Orchidaceae • Asteraceae • Composites have flowers closely bunched together in a head. • 22,000 species. • Ovary with 1 ovule • Disk and ray flowers. • Orchidaceae • Orchid flowers are showy and zygomorphic. • 24,000 species. • Ovary with 1,000s of ovules. • Cuplike lower petal.

11. Fruit Related Terminology • Fruit- a mature ovary. • Ovary- the enlarged basal portion of a carpel. • Carpel- the vessel that encloses the ovule/s; forms the gynoecium. • Ovule- the structure that contains the female gametophyte with egg cell, including the nucellus and integuments. • Seed- a mature ovule. • Locules- chambers in the ovary that contain the ovules.

12. Parietal Axile Free central

13. Fruit Classification • Fruit derived from more than 1 pistil • Multiple fruit- develop from a cluster of mature ovaries produced by a cluster of mature flowers. • Pineapple. • Aggregate fruit- develop from several separate carpels of a single flower. • Raspberry, strawberry, blackberry.

14. Simple Fruit Types- fruit derived from 1 pistil • Fleshy Simple Fruits • Berries- fleshy inner layer. Tomatoes, bananas, grapes. • Pepo- a berry with a thick, leathery, inseparable rind. Cucurbitaceae. • Hesperidium- a berry with a thick, leathery, separable rind. Citrus. • Pome- fleshy hypanthium. Pear, apple. • Drupes- stony endocarp. Peach, cherry, olive. • Dry Simple Fruits • Dehiscent- tissue of the mature ovary wall splits open, freeing the seeds. • Legume- dehisces along 2 sutures. Bean. • Indehiscent- tissue of the mature ovary wall remains sealed with seeds remaining in the fruit. • Nut- hard pericarp, usually one-seeded. • Achene- small. Dandelion.

15. Fruits and seeds have evolved in relation to their dispersal agents • Wind-borne fruits & seeds. • Floating. • Fleshy for animal dispersal. • Attachment to animals.