gymnosperm & angiosperm - brookings school...

26
27 2004-2005 AP Biology Gymnosperm & Angiosperm Rise of the seed plants

Upload: hoangduong

Post on 09-Jun-2018

216 views

Category:

Documents


0 download

TRANSCRIPT

27

2004-2005AP Biology

Gymnosperm& Angiosperm

Rise of theseed plants

28

2004-2005AP Biology

Gymnosperm: conifers Characteristics

vascular heterospory

male vs. female gametophytes seeds

naked seeds (no fruit) pollen

contain male gametophyte life cycle dominated by sporophyte stage

coniferous trees you are familiar with are diploid reduced (microscopic) gametophyte reduction of gametophyte protects delicate egg

& embryo in protective sporophyte protected from drought & UV radiation

29

2004-2005AP Biology

Evolutionary trends in land plants Reduction in gametophyte

bryophytes pteridophytes gymnospermangiosperm

30

2004-2005AP Biology

Early Gymnosperm: ginkgo

31

2004-2005AP Biology

Early Gymnosperm: cycads

32

2004-2005AP Biology

Gymnosperm: conifers

33

2004-2005AP Biology

Cones & naked seeds

34

2004-2005AP Biology

Gymnosperm (Pine) life cyclefemale

gametophytein cone

malegametophyte

in pollen

sporophytein seed

meiosis meiosis

fertilization

35

2004-2005AP Biology

male

female

male (pollen) cones

female cones

sporangium & pollen

pine embryo

36

2004-2005AP Biology

Angiosperm: flowering plants Characteristics

vascular heterospory

male vs. female gametophytes flower

specialized structure for sexual reproduction seeds within fruit pollen life cycle dominated by

sporophyte stage trees & bushes you are familiar

with are diploid reduced (microscopic)

gametophyte

37

2004-2005AP Biology

Angiosperm: flowering plants

38

2004-2005AP Biology

Co-evolution: flowers & pollinators

39

2004-2005AP Biology

Angiosperm: fruiting plants

40

2004-2005AP Biology

Angiosperm life cycle

41

2004-2005AP Biology

Flower Modified shoot with 4 rings of

modified leaves sepals petals stamens

male carpals

female

42

2004-2005AP Biology

43

2004-2005AP Biology

Angiosperm life cycle

femalegametophyte

in ovary

malegametophyte

in pollen

sporophytein seed

fertilization

44

2004-2005AP Biology

45

2004-2005AP Biology

Angiosperm Flowering plants

flowers and fruit monocots

1 seed leaf leaves with parallel

dicots 2 seed leaves leaves with net-like venation

46

2004-2005AP Biology

Dicot dicots

2 seed leaves leaves with

net-likevenation

broad leafplants

47

2004-2005AP Biology

Monocot monocots

1 seed leaf leaves with

parallel grasses,

grains, bulbs

48

2004-2005AP Biology

Evolutionary trends Vascular tissue

tubes for transport non-vascular

bryophytes - mosses vascular

pteridophytes - ferns gymnosperm - conifers angiosperm - flowering plants

Evolutionary advantage? adaptation to dry terrestrial conditions allows increased size (think trees!)

49

2004-2005AP Biology

Evolutionary trends Sperm dissemination

flagellate (swimming) sperm bryophytes - mosses pteridophytes - ferns

wind-blown or animal-carried pollen gymnosperm - conifers angiosperm - flowering plants

Evolutionary advantage? adaptation to dry terrestrial conditions

eliminated water requirement for fertilization

50

2004-2005AP Biology

Evolutionary trends Seeds

seedless plants bryophytes - mosses pteridophytes - ferns

seed plants gymnosperm - conifers angiosperm - flowering plants

Evolutionary advantage? adaptation for reproduction in diverse

terrestrial environments resistant, dispersal stage

51

2004-2005AP Biology

Evolutionary trends Reduction of gametophyte

gametophyte dominant bryophytes - mosses

sporophyte dominant, free living gametophyte pteridophytes - ferns

sporophyte dominant, reduced gametophyte gymnosperm - conifers angiosperm - flowering plants

Evolutionary advantage? adaptation for reproduction in diverse

terrestrial environments reduction of gametophyte protects delicate egg & embryo

in protective sporophyte protected from drought & UV radiation

52

2004-2005AP Biology

Evolutionary trends The 4 groups represent 4 great

episodes in the evolution of land plants evolution of land plants from ancestral

green algae → mosses evolution of vascular plants

ferns evolution of seeds

gymnosperm evolution of flowers

angiosperm