Transcript chapter 25-2 - mshernandezscience

Plant Reproduction
Not just birds and bees do it…
SEXUAL REPRODUCTION IN
SEEDLESS PLANTS
1. Sexual Reproduction in
Seedless Plants
a. Fertilization for seedless plants usually
occurs during or soon after rain, when
the spores are covered with water.
b. Only then can the sperm swim to the
egg.
c. Once together they form a sporophyte,
which can then continue its life cycle.
SEXUAL REPRODUCTION
IN SEED PLANTS
2. Sexual Reproduction in
Seed Plants
a. Gymnosperms & Angiosperms (seed plants)
do not release spores in rain like other
plants
2. Sexual Reproduction in
Seed Plants
b. Examples of Reproductive Structures:
 Pollen Grain - male gamete. Wind
and animals transport pollen grains
 Ovule - female gamete. Stays on
plant
3. Reproduction Terms
a. Pollination - transfer of pollen grains from
the male structures to the female structures.
b. Seed Coat - the hardened outer cell layers
of an ovule that protects the embryo.
3. Reproduction Terms
C. Cotyledon - leaf-like structures (seed
leaves) that are a part of the embryo.
Douglas fir
i.
Gymnosperms – have two or more
cotyledons
ii.
Angiosperms:
Monocots – have 1 cotyledon
 Dicots – have 2 cotyledons

Monocot vs Dicot cotyledons
3. Reproduction Terms
D. Gymnosperms – type of plant where
seeds develop within cones.
E. Angiosperms – type of plant where the
seeds develop within flowers.
Male
Female
4. Cones
a. Benefit: Offer protection
b. Drawback: Wind
pollination . Animals don’t
usually eat cones.
c. Some species have “berrylike” cones for distribution
(juniper and yew)
Berry like
Male
5. Flowers
a.
b.
Benefit: Attracting
pollinators for more
directed
“reproduction”
Drawback: Not as
protective as cones
(some flowers are
tasty to both animals
and people).
5. Flowers
C. Flowers Have Four Whorls (Layers):
i.
ii.
Sepals – the outermost layer= protection
when the flower is a bud.
Petals –used to attract the pollinators.
Petal
Sepal
5. Flowers- 4 whorls
iii. Stamens –make pollen.
– pollen-producing sac on top of
stamen.
 Anther
iv. Pistils –produces ovules.



Ovary – the pistil’s swollen lower portion is the
where the ovules develop.
Style – the stalk that rises from ovary.
Stigma – the swollen, sticky tip of style.
Pistil
spot
Stamen
Petal
Christmas Lillium
(Lilium
longiflorum).
1. Stigma,
2. Style,
3. Stamens,
4. Filament,
5. Petal
D. How flowers attract pollinators
Color (even white)
ii. Scent - Some smell sweet (promise of
nectar, some smell terrible (flies are
attracted to lay their eggs)
iii. Bribes – nectar
iv. Lies - hormones and shape may deceive
wasps
i.
E. Examples of Flower Pollinators:
a. Bees
b. Flies
c. Moths
d. Hummingbirds
e. Bats
f. Wind
6. Fruits
A fruit is a ripened ovary
b. The fruit protects the seeds and also allows
for distribution of the seeds
a.
ASEXUAL REPRODUCTION
IN PLANTS
7. Asexual or Vegetative
Reproduction in Plants
a. Asexual reproduction in plants involves
the vegetative (non-reproductive) parts of
the plants, such as stems, roots, and leaves.
b. Runners, corms, bulbs, tubers, and
rhizomes are some of the structures
involved.
c. The benefit of asexual reproduction is
speed!
Name
Description
Examples
Runner
Horizontal, above ground stems
Bermuda grass
Bulb
Very short stem with
thick fleshy leaves;
only in monocots
Onions, daffodils,
tulips
Corm
Very short, thickened
underground stem
with scaly leaves
Gladiolus, crocus
Rhizome Horizontal
underground stem
Iris, ferns, sugar
cane
Tuber
Potatoes
Swollen, fleshy,
underground stem
Runners
Bulb
Corm
Rhizome
Tuber