What do I need to know about plants?

1. The Plants
Kyle Guzik

2. Arabidopsis Thaliana

3. The BSLC Greenhouse

4. Genetic Modification with
Green Fluorescent Protiein

5. Kingdom Plantae
• Plants are multicellular eukaryotes with well-
developed tissues.
• Plants live in a wide variety of terrestrial
environments.
• There are also aquatic plants.

6. Water lily of the family
Nymphaeaceae

7. Is this a plant?
• Ascophyllum nodosum
• This is a seaweed of the
northern Atlantic Ocean,
also known as
Norwegian Kelp, Knotted
Kelp, knotted wrack or
egg wrack. It is not a
plant but rather a large
common brown algae.

8. Land vs. Water
• Land existence makes photosynthesis more
effective. Water filters light.
• Carbon dioxide and oxygen are in higher
concentrations and diffuse more rapidly in air.
• Land plants have adaptations to reduce the loss
of water.
• Leaves are covered with a waxy cuticle that holds
in water.
• The leaves have openings know as stomata that
open and close to regulate gas and water
exchange.

9. A Stomatal Complex

10. Relationship to Algae
• Plants are believed to be closely related to
green algae.
• Both use chlorophylls a and b.
• Both use starch as the food reserve.
• The cell walls of both contains cellulose.
• Both form a cell plate during cell division.
• Unlike green algae, plants have sex organs
with an outer layer of reproductive cells.

11. Alternation of Generations
• The sporophyte
generation is a
diploid generation
that produces
haploid spores by
meiotic cell division.
• The gametophyte
generation is a
haploid generation
producing haploid
gametes by mitotic
cell division.

12. Nonvascular plants
• Plants are divided into two main groups: non
vascular and vascular plants

13. Hornworts
• Division Anthocerotophyta

14. Liverworts
• Division Hepatophyta

15. Liverworts
• The division hepatophyta contains 10,000 species
of liverworts.
• This name comes from the liver shaped lobes of
the plant.
• Marchantia, for example has a flat lobed thallus
about a centimeter in length. The upper surface
of the thallus is smooth the lower surface bears
numerous rhizoids projecting into the soil.
• It reproduces sexually and asexually.

16. Liverworts
• Rhizoids are the rootlike hairs that anchor the
bryophytes and absorb water and minerals
from the soil.
• Asexual reproduction involves gemmae in
gemmae cups on the upper surface of the
thallus.

17. Liverworts
• Sexual reproduction depends on antheridia and
archegonia
• Antheridia are on disk-headed stalks and produce
flagellated sperm.
• Archegonia are on umbrella-headed stalks and
produce eggs.
• A Zygote develops into a tiny sporophyte
composed of a foot, short stalk, and capsule.
• Spores produced within the capsule of the
gametophyte are disseminated by the wind.

18. Mosses
• Division Bryophyta
• Interestingly, Spanish Moss is not a bryophyte but
rather a member of Bromeliaceae, the same
family that contains pineapples.

19. Mosses
• There are about 12,000 species of mosses in the
division bryophyta.
• Mosses are found in the Arctic through the
tropics to parts of the Antarctic.
• Moss prefers damp shaded localities; however
some survive in desserts while others live in bogs
and streams.
• Mosses can store large quantities of water in
their cells. When dried out they become
dormant, but turn green again after some rain.

20. Mosses
• Most mosses can reproduce asexually by fragmentation.
• The moss life cycle begins with an algalike protenema developing
from germination of a haploid spore.
• Three days of favorable growing conditions produce uprights shoots
covered with leafy structures.
• Rhizoids anchor the protonema, to which the shoots are attached.
• The shoots bear antheridia and archegonia at their tips.
• Antheridia produce flagellated sperm which need external water to
reach eggs in archegonia.
• Fertilization results in a diploid zygote that undergoes mitotic
division to develop a sporophyte.
• The sporophyte consists of a foot, stalk, and upper capusle
(sporangium) where spores are produced.
• The sporophyte is initially green and photosynthetic; at maturity it
is brown and non-photosynthetic.

21. Nonvascular Plants
• Lack specialized tissues for transporting water,
minerals, and organic nutrients
• They lack true roots, stems, and leaves, although
they have rootlike, stemlike, or leaflike structures.
• The gametophyte is the dominant generation.
• Flagellated sperm swims to the vicinity of the egg
in a continuous film of water.
• The sporophyte is attached to and derives
nourishments form the photosynthetic
gametophyte.

22. Vascular Plants
• Xylem is a vascular
tissue that conducts
water and minerals up
from the soil.
• Phloem is a vascular
tissue that transports
organic nutrients from
one part of the plant to
the other.

23. Organs of Vascular Plants
• Roots absorb water and minerals from the soil
• Stems conduct water and mineral to leaves
and conduct organic nutrients from leaves to
the roots.
• Leaves are adapted to maximize
photosynthetic activity; they are covered by a
waxy cuticle.
• Leaves have openings (stomates) that open
and close to regulate water and gas exchange.

24. Reproduction of Vascular Plants
• The diploid sporophyte generation is
dominant; this is the generation that has
vascular tissue.
• Seedless vascular plants (ferns and their allies)
disperse their species by producing
windblown spores.
• In seed plants there is a separate
microgametophyte (male) and
megagametophyte (female)

25. Whisk ferns (division Psilotophyta)
• Occur in Arizona, Texas,
Louisiana, Florida,
Hawaii, and Puerto Rico
• Have no leaves or roots,
posses a branched
rhizome with rhizoids
and a mycorrhizal fungus
that helps gather
nutrients.
• Aeriel stems with tiny
scales fork repeatedly
and carry on
photosynthesis.

26. Club Mosses (division Lycopodophyta)
• ~ 1,000 species of club
moss
• Tightly packed, scalelike
microphylls cover stems
and branches; each
contains one strand of
vascular tissue.
• Most live in tropics or
subtropics as epiphytes,
plants that live on trees
without harming them.

27. Horsetails (division Equisetophyta)
• A rhizome produces
aerial stems that stand
about 1.3 meters tall.
• Tough, rigid stems have
silica in the cell walls.
• “scouring rush”

28. Ferns (division Pteridophyta,)
• 12,000 species of ferns belong to division
Pterodophyta.