Download Plants

Plants
Zebra Book Page 608
• Copy the Plant Kingdom phylogenetic
tree in your notes
• Fill out the Nonvascular vs. Vascular
Plant chart using pages 610-621
*(Alligator book pgs. 617-622)
Plant Structure & Function
Don’t make
it more
complicated
than it is!
Stems
• 2 Functions
– Support the leaves (hold them up to the
light)
– Transport water & food within the plant via
its vascular system
Vascular System
• Xylem
– Plant tissue that transports water & dissolved
minerals from the roots up toward the leaves
• Phloem
– Plant tissue that transports glucose from the
leaves down the plant
Xylem & Phloem are arranged in
vascular bundles
3 Types of Stems
1. Dicot Stems
• Bundles arranged in a circle around
the outer edge of the stem
– Examples: Tomato, cucumber & weeds
Phloem
Fiber
Cells
2. Monocot Stems
• Randomly arranged bundles of vascular tissue
• Examples:
– Grasses, corn, lilies
3. Woody Stems
• Have a thin layer called cambium (also called
the growing layer) between the xylem &
phloem
– New cambium grows 1x per year, thus giving us tree
rings!
• Bark = outer portion of stem
– Inner portion of bark contains phloem
• If you peel the bark, you could kill the tree
Roots
• Functions:
– Absorb water and dissolved minerals
– Anchor the plant to the soil
Structure of Roots
• Primary root
– First root to grow out of a seed
• Taproot
– If the primary root grows down into the soil and
remains the largest root, we call it the taproot
• Ex. Carrots, beets, turnips & sweet potatoes are
taproots that store food
• Fibrous root
– If the primary root develops into many small roots
near the surface of the soil, we call it a fibrous
root
• Ex. Many monocots such as grasses & orchids
* Note - Root hairs increase absorptive surface area
Leaves
• Function #1:
– Photosynthesis (plants make sugar for food)
& Respiration
• Function #2:
– Transpiration (gas exchange in leaves that occurs
through the stomata)
Changes in the shape of the guard cells
result in opening & closing of stomata.
Stomata Lab
Procedure:
1. Paint a thick patch (at least one square centimeter) of
clear nail polish on the underside of the leaf surface
being studied.
2. Allow the nail polish to dry completely.
3. Tape a piece of clear tape to the dried nail polish patch.
4. Gently peel the nail polish patch from the leaf by pulling
on a corner of the tape and "peeling" the polish off the
leaf. This is the leaf impression you will examine.
5. Tape your peeled impression to a microscope slide.
Things to Consider:
1. Under scanning and low power, the slide will
look like smeared nail polish!
2. Under medium power, you should be able to
see the stomata!
Article: 32,000 Year Old Plant
Brought Back to Life – Oldest Yet!
National Geographic News
February 21, 2012
As a group, answer the
following questions:
1. How do scientists know how old the seeds are?
2. How were scientists able to germinate 32,000
year old seeds?
3. What is permafrost? Why could it be important
to understanding the past?
4. How could this discovery be important to us in
the future?
Plant Reproduction
Angiosperms
Flower – Primary unit of angiosperm
reproduction
5 Parts of a flower (refer to handout)
•
•
•
•
Receptacle
Sepals
Petals
Stamen
– Anther & filament
• Pistil
– Stigma, Style & Ovary
Pollination
• The transfer of pollen from the anther to a
stigma of a flower of the same species by wind
or animal
• 2 Types
– Cross Pollination – transfer of pollen from 1 plant
to another of the same species
– Self-pollination – transfer of pollen from one flower
to another on the same plant
Fertilization
• Union of gametes (pollen & ovule)
• Steps:
1. Pollen grain lands on stigma
2. A pollen tube grows from the stigma down
the style and into the ovary
3. The sperm then travels down the tube into
the ovary where it fuses with the ovule
4. The zygote (baby plant) begins to develop &
will eventually form a seed (the ovary will
develop into the fruit)