Transcript AngiospermReproductionCh20

Plants:
Angiosperms
Remember…..
 What is the group of flowering plants?
Angiosperms
 In what structure is the plant embryo found
which is made from a flower?
Seeds
 What is the protective structure that
surrounds a seed called?
Fruits
A. Flowers
1. Flowers are organs of
reproduction in angiosperms
2. Flowers contain male and
female reproductive parts
3. Parts of a flower
a. Sepals- kinds of leaf that protect the bud, can
be green or brightly colored
b. Petals- kinds of leaf inside the sepals, protect
reproductive parts of a flower
 sometimes have brightly colored petals and nice
smell to attract pollinators (exs. roses and lilies)
 sometimes white or green and no smell (exs.
grasses)
c. Reproductive structures of a
flower
1. Pistil (carpel)- female reproductive
structure
 Usually one per flower, in the center
 contains stigma, style and ovary
2.Stamen- male reproductive structure
 Usually several per flower, around the pistil
(carpel)
 Contains anther and filament
4. Types of flowers
a. Perfect flowers- both male and female
parts, stamen and pistil/carpel
 Ex lily
b. Imperfect flowers- only male (stamen) OR
female (pistil/carpel) parts but not both
 Ex zucchini
B.
Reproduction
with Flowers
Seeds and Fruits
Stamen:
Male reproductive Structure
 1. Stamen- contains anthers and filaments
a. Filament- stalk that holds anther
b. Anther- produces pollen grains which
contain plant sperm, pollen released when it
bursts open
Pistil/Carpel:
Female Reproductive Structure
 2. Pistil/carpel contains stigma, style and
ovary
a. Stigma- sticky top that catches pollen
b. Style- tube that connects stigma to ovary
c. Ovary- bottom of pistil that contains ovules
with eggs inside
Ovary
Pollination
 3. Pollination- movement of pollen from
anther of stamen to stigma of pistil/carpel
 Can occur by wind, insects, bats, birds, and
water
Pollination
a. Self pollination- pollen
travels from anther of stamen
of a flower and lands on
stigma of pistil of SAME
flower, or on different flower
on SAME plant, must be
perfect
b. Cross pollination-pollen
travels from stamen of a
flower to pistil of another
flower on a DIFFERENT but
similar plant, flowers can be
perfect or imperfect
Self pollination vs Cross pollination
Same Plant
Different Plants
Fertilization
 4. Fertilization- as part of sexual
reproduction it is the joining of the nuclei of
male (sperm) and female (egg) sex cells of
flowers
Takes place inside the pistil
Steps of pollination and Fertilization
a. Pollen grain from anther of stamen lands on
stigma of pistil
b. One cell from pollen forms a pollen tube from
stigma through style to ovary
c. Other cell from pollen is called sperm &
moves through pollen tube to ovule of ovary
where egg is
d. Nuclei of sperm and egg join (fertilze) to form
a zygote
e. Fertilzed egg develops into a seed
f. Seed contains an embryo,or baby plant, plus
a cotyledon (endosperm)
seed
embryo
5. Seeds and fruits
a. Seeds- formed from mature (eggs in)
ovules
b. Fruits- from mature ovary, form around
seeds to protect them
c. Name some plants that have fruits.
All angiosperms have fruits
C.
Parts of a seed
and germination
1. Seed parts
a. Seed coat- protects the embryo
b. Cotyledon- inside seed, used to absorb
food from endosperm of seed for
developing plant embryo
 Monocots (1 cotyledon) vs dicots (2
cotyledons)
Seed parts
c. Embryo- baby plant; has tiny root, stem and
cotyledons (develop into leaves)
d. Hilum- scar where seed was attached to
ovary of flower
2. Germination
of seeds
Germinationdevelopment of
embryo inside seed
into a new plant with
good soil and water
3. Seed dispersal
 Seed dispersal- Movement of seeds for
germination
By wind, water, animals eating
fruits and depositing seeds
or carrying seeds on fur
D.
Asexual
reproduction in
plants
Asexual reproduction
• 1. Asexual Reproduction involves one parent
• Offspring are genetically identical to their parents
Types of Asexual Reproduction
 Vegatative propagation- asexual
reproduction that uses plant parts to grow
new plants
 Runners- underground stems
 Tubers- “buds or eyes” part of
underground stems
 Spores- airborne particles stored in spore
cases
 Bulbs- leafy, underground stems
 Cuttings- root, leaf or stem pieces
Tubers
Exs potatoes,
yams
Cuttings- asparagus
roots
bulbs
runners
E.
Tropisms
Tropisms/Plant
Responses
Tropism- growth response to a stimulus,
(usually by growing in a certain direction)
Stimulus- a change that causes response
 Ex: light, touch, gravity or water
5. Types of tropisms
&
Positive Vs Negative
Tropisms
Positive Tropism
 Growth toward the stimulus
Negative Tropism
 Growth away from the stimulus
a. Phototropism
 Plant’s growth in response to light
 Leaves and stems grow towards light
b. Gravitropism
 Plant’s growth in response to gravity
 Roots grow towards gravity and stems
grow away from it
c. Hydrotropism
 Plant’s growth in response to water
 Roots grow towards water
d. Thigmotropism
 Plant’s growth in response to touch
 stems grow due to touch, grow around a
structure
 Example: poison ivy