Sexual Life cycles Plant structure and Phylogeny - PowerPoint PPT Presentation

Loading...

PPT – Sexual Life cycles Plant structure and Phylogeny PowerPoint presentation | free to view - id: 7494d1-OWIyM



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Sexual Life cycles Plant structure and Phylogeny

Description:

Sexual Life cycles Plant structure and Phylogeny The Angiosperms Outline Brief review 9. ALTERNATION OF GENERATIONS 8. PLANT EVOLUTION 7. ANGIOSPERM LIFE HIST. – PowerPoint PPT presentation

Number of Views:41
Avg rating:3.0/5.0
Slides: 34
Provided by: ccsf158
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Sexual Life cycles Plant structure and Phylogeny


1
Sexual Life cycles Plant structure and Phylogeny
  • The Angiosperms

2
Outline
  • Brief review
  • 9. ALTERNATION OF GENERATIONS
  • 8. PLANT EVOLUTION
  • 7. ANGIOSPERM LIFE HIST.

3
Define sex cell.
4
All life is organized into 3 domains
  • 2 Domains of prokaryotes, 1 of all eukaryotes
  • Bacteria Archaea- prokaryotic
  • Eukaryota- Includes all 4 eukaryotic kingdoms
    protista, animalia, plantae, fungi

5
Most of the many Eukaryotic species reproduce
sexually
6
Despite an inherent twofold cost, higher species
reproduce sexually
  • Sexually reproducing species must have 2
    offspring to break even
  • 2 offspring from an asexually reproducing species
    doubles the population

7
Animal species alternate between diploid
(mitotic) and haploid (meiotic)
In animals, only the diploid stage is
multicellular
8
Sexual life cycle of Animals
  • gametic or diplontic
  • - meiosis forms gametes, no spores
  • - mainly like a sporophyte (2n)
  • - produce gametes (1n) via meiosis
  • - fertilization results in zygote (2n)
  • - sporophyte grows via mitosis 

9
Schematic gametic life cycle
Sporophyte?
10
Many fungi work the opposite way
  • zygotic or haplontic
  • - zygote undergoes meiosis
  • - mainly like a gametophyte (1n)
  • - produce gametes (1n) via mitosis
  • - fertiliz. results in zygote (2n)
  • - produce spores (1n) via meiosis
  • - gametophyte grows via mitosis 

11
Most plants have two multicellular life cycle
stages- gametophyte and sporophyte
  • plants - sporic or diplohaplontic
  • - alternate sporo- gametophyte
  • - meiosis forms spores
  • - sporophytes (2n) dominate
  • - produce spores (1n) via meiosis
  • - gametophyte (1n) develops inside cone/flower
    via mitosis
  • - prod. gametes (1n) via mitosis
  • - fertiliz. results in zygote (2n)
  • - sporophyte grows via mitosis

12
8. PLANT EVOLUTION
13
Plant phylogeny
14
The Phylum Bryophyta includes liverworts and
mosses
  • Simplest terrestrial plants- avascular
  • evolve multicell. terrestrial
  • - adapt to gravity, so small/low
  • - no roots, rhizoids only anchor
  • sperm needs H2O to fertilize ova

15
In mosses, the sporophyte and gametophyte are
similar in size
16
Ferns are vascular plants
  • ferns (Phylum Pterophyta)
  • evolve vasculature (vessels),
  • allows fronds to grow large
  • - true roots absorb H2O, minerals
  • - no seeds, sperm still needs H2O

17
The gametophyte is smaller in the fern life cycle
18
The gametophyte nurtures the young sporophyte
19
Conifers are the prototypical gymnosperm
  • gymnosperms (Phy. Coniferophyta)
  • - evergreen needles reduce evap.
  • ova in larger female cones
  • sperm in pollen grains from male cones,
    dispersed by wind
  • no fruit, naked seeds protect provide
    nutrients to embryo 

20
Gymnosperms include cycads ginkoes
21
Gymnosperms have no flowers or fruits
  • Mostly wind-pollinated
  • The most massive indiviual living things- Giant
    sequoia

22
The tallest and most massive- here in CA
23
Male Female Gametophytes are greatly reduced in
gymnosperms
24
Angiosperms are flowering plants
  • angiosperms (Phylum Anthophyta)
  • - deciduous leaves drop off in winter, surv. low
    temp/H2O
  • flowers attract animal pollinators with
    color-smell-nectar,
  • more efficient for fertilization
  • endosperm in seeds stores nutrients, esp. in
    grains/nuts
  • fruit attracts animals to disperse fertilize
    seeds, reduces comp.

25
Basic (monoecious) Flower structure
26
The male angiosperm gametophyte is even smaller
  • inside anthers
  • - meiosis prod. microspore (1n)
  • - becomes the pollen grain
  • male gametophyte (1n)
  • - with 2 sperm cells tube cell

27
The female gametophyte houses the seed
  • inside carpels
  • - meiosis prod. megaspore (1n)
  • becomes the ovary
  • female gametophyte (1n)
  • ovum central cell (nn)

28
Pollination
  • pollination - pollen grain to stigma
  • - tube cell grows pollen tube to reach ovary
  • double fertilization
  • - 1st sperm cell (1n) ovum (1n)
  • zygote (2n sporophyte)

29
The seed is a capsule containing a plant embryo
  • - 2nd sperm cell central cell (nn)
    endosperm (3n, food in seed)
  • seed
  • - seed coat around endosperm
  • - zygote grows into embryo
  • via mitosis
  • - ovary around seed becomes fruit

30
The plant embryo is already formed
  • embryo
  • - epicotyl becomes shoot
  • - hypocotyl becomes root
  • - cotyledons becomes leaves

31
Plant phylogeny
32
6. MONOCOTS VS. DICOTS
  • angiosperms - flowering plants
  • - divided into 2 major groups
  • monocots - corn, grasses
  • - 1 cotyledon (embryonic leaf)
  • - narrow leaves with parallel veins
  • - flower parts in 3s, fibrous roots
  • - vascular bundles scattered,
  • primary growth only
  • dicots - most other angiosperms
  • - 2 cotyledons absorb endosperm
  • - broad leaves with network veins
  • - flower parts in 4 or 5s, taproot
  • - vasc. bundles arranged in ring,
  • secondary growth possible

33
Monocots vs. Dicots
About PowerShow.com