Transcript Basic Plant Structure

BELL WORK (Buff Binder):
Copy the question below and write your
entire answer.
When a seed falls on its side, the roots still
grow downward. This is an example of –
a. phototropism
b. gravitropism
c. thigmotropism
d. hydrotropism
Set up the journal pages below:
If you didn’t do it
yesterday…
For today’s CORNELL
notes…
• Page: 64
• Date: 2-17-15
• Title: Flower
Structure
• Tape yesterday’s
reading part onto
this page!
• Page: 65
• Date: 2-18-15
• Title: Plant
Reproduction
• Essential Question:
How do plants
reproduce?
Anticipation Guide:
STAND UP if the statement is true;
SIT DOWN if the statement is false.
1. Some plants are single celled organisms.
2. Plants are prokaryotic and animals are
eukaryotic.
3. Plants are photosynthetic autotrophs.
4. Plants have chitin in their cell walls.
5. Pollination is a part of plant reproduction.
Plant Parts/Systems
• Reproductive: Flower (with
male and female parts)
• Transport: vascular tissues
in stem
• Nutrient & Support: Leaves
+ Stem + Roots
• Response: Hormones +
Tropisms
All of these parts and systems work together
to help a plant maintain homeostasis.
Plant Reproduction
Flowers: reproductive organs of some plants
Male Reproductive Structure:
Stamen = anther +
filament
Meiosis occurs on the
anther to produce pollen
(sperm)
Filament = stalk that
supports the anther
Female Reproductive Structure:
Pistil = stigma + style
+ ovary
Sticky stigma =
receives pollen from
the anther
Pollen grows a tube
down through the
style
Meiosis occurs in the
ovary to produce
ovules (eggs)
So, this is what
sexual
reproduction in
plants looks
like...awkward
Pollination
The pollen grain contains the male gamete
Pollination: transfer of pollen from the anther to the
stigma
Click to view the animation
• This is an example of cross-pollination as the pollen
travels from one flower to a different flower. This is
desirable in plants as it promotes genetic variation.
How does pollen get to the stigma?
Wind: Dull, scentless
flowers with reduced petals
Bees/Butterflies: Bright color, nectar,
scent. They sip nectar, get pollen on coats,
transfer pollen from flower to flower
Birds: Nectaries, bright
colors, tube-like flowers
Moths: White petals,
open at night
Flies: Rank odor, flesh
colored petals
Self-pollination occurs when pollen falls from the
anther onto the stigma of the same flower
• Self-pollination is
not desirable as it
reduces genetic
variation
Flowers will prevent self-pollination by
either having stigma above stamen
or having parts mature at different times
Seed and Fruit Development
After fertilization,
the petals and
sepals fall off
flower
Ovary “ripens”
into a fruit
(hormones)
Ovule develops
into a seed
Flower to Fruit
Seed Dispersal Mechanisms
Seed Dispersal MechanismsAllow plants to avoid competition with parent plant
Wind - Flight mechanisms, like parachutes, wings, etc.
Ex.
Dandelion, maples, birch
Animals - Fleshy fruits which animals eat, drop undigested
seeds in feces or burrs which stick to animals’ coats
Gravity - Heavy nuts fall to ground and roll
ex. acorns
Reproduction without flowers
• Mosses, ferns, and related plants have swimming sperm.
The leafy tips of mosses produce male and female sex
cells. Male sex cells swim through water on the
surface of the plant to reach and fertilize female
cells. Fertilization produces a spore capsule, that scatters
spores into the air.
What kind of environmental
conditions would be required for
reproduction in these plants?
What kinds of limits does external
reproduction impose on these
plants?
Germination
The seed coat surrounds and protects the embryo and
keeps the contents of the seed from drying out.
Enzymes are used in seed germination
Plumule
starch
embryo plant
amylase
secreted
maltose
Radicle
This is the first part to
grow out of the seed
as it needs to absorb
more water
Water enters the
seed and
activates
enzymes.
The enzymes
break starch
down into
maltose and then
glucose. The
glucose is used in
respiration to
provide energy
for growth
Debrief/Summary:
• Explain how gravitropism and a
plant’s reproductive system work
together.
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