Download Plant Science HL

Plant Science HL
Red Book Sections: 9.1 to 9.3
Dicotyledonous: Stem Tissue
• Pith: a storage and support area.
• Cortex: helps with the support.
• Epidermis: mostly there for
protection, may allow gas exchange.
• Xylem: carries water and dissolved
minerals from the roots to the leaves.
• Phloem: transports organic nutrients
throughout the plant.
• Cambium: its an area of rapidly
dividing cells that differentiate into
xylem and phloem.
Dicotyledonous: Leaf Tissue
• The palisade mesophyll needs to be at the top of the leaf because the most
amount of light is available there, and this area of the cell is rich in chloroplast =
max photosynthesis.
• Veins are distributed through out the leaf carrying raw materials for
photosynthesis, which is why they’re in the middle so they can be close to all cells.
• The spongy mesophyll is just above the stroma allowing continuous channels for
gas exchange.
• The stroma are at the bottom of the leaf because of lower temperatures which
minimizes water loss.
Monocots vs. Dicots
YOU NEED TO KNOW AT LEAST THREE OF THESE FOR THE EXAM 
Plant Modifications
Modifications occur in: Roots, Stems, and….. Leaves
The examples you should recognize:
Tubers like Potatoes
BULBS like Onions
Tendrils like Twirly Vines
Storage Roots like Carrots
Plants Doing the Limbo
Plants show indeterminate growth because of meristematic tissues.
Dicot. plants have two types of this tissue : Apical and Lateral
Apical meristematic tissue occurs at the tips of roots and stems resulting in primary growth. This allows
the roots to extend through the soil.
Lateral tissue allows growth in thickness of plants, also known as secondary growth. (mainly woody
plants) These plants have two kinds of lateral tissue: Vascular cambium and Cork cambium.
Remember LAT = FAT
•
Phototropism is when a plant response to
light. Its essential for a plant in crowded areas
and seedlings. Auxins is a plant hormone
responsible for this, and only work on plants
cells with auxin receptors. They seem to
increase the plant’s flexibility of the plant cell
walls enabling cell elongation on the side of
the shoot necessary to cause growth towards
the light.
Transport in the Angiospermophytes
Mineral Movement
•
•
Mineral ions move from the soil to the roots in three ways: diffusion of minerals and mass
flow of water, aid provided by fungal hyphae, and active transport.
The fungal hyphae create larger surface area, minerals dissolve into water and move into the
root because of concentration differences, and active transport using pumps.
How The Pump Works
•
Potassium ions move into the root through
specialized transport proteins call potassium
channels. The proton pump is the most important
active transport protein in the plasma membranes
of plant cells.
• First the proton pump uses energy from ATP to
pump hydrogen ions out of the cell. Then this
results in a higher H+ ion concentration outside the
cell than inside creating a negative charge inside
the cell. This gradient results in the diffusion of
hydrogen ions back into the cell. The voltage
difference is called a membrane potential. The
hydrogen ion gradient + the membrane potential
represent forms of potential energy that can be
used to absorb mineral ions.
Transpiration
•
•
Transpiration: the loss of water vapor from leaves and other aerial parts of the plant.
Transpirtation is affected be abiotic factors in the environment, these are the ones you
need to know.
Envi. Factor
Effect on Transpiration
Light
Speeds us transpiration by warming the leaf, opening stomata.
Temperature
Increasing temperature increases transpiration b/c more water evaporates.
Wind
Increases the rate of transpiration because humid air is moved away from stomata.
Humidity
Decrease in humidity = increase in transpiration because of diff. in water concentration
Controlling Transpiration
LABEL ME!!
•
Its important to note that guard cells regulate
transpiration by opening and closing the stroma,
but it is the presence of the hormone abscisic
acid that causes the guard cells to close the
stroma.
• Some plants, known as xerophytes have
modifications that help reduce transpiration.
Four of these modifications include:
1. Small, thick leaves that reduce water loss by
reducing surface area.
2. They have a thickened, waxy cuticle.
3. Some plants shed their leaves in dry months
and become dormant.
4. Some have a reduced number of stroma
decreasing the number of opening water loss
can occur at.
Riding along the Transpiration Stream
•
Water moves along the transpiration
stream through the xylem vessels.
• The two major cell types used in the
vessels include Vessel Elements and
Tracheid.
• They are both made of dead cells that
have thick lignified walls for support.
• They are also attached end to end to
keep the flow of water continuous.
•
In the picture label where transpiration
pull, cohesion, adhesion, and
evaporation are occurring.
Angiospermophytes Getting Busy
• Pollination: transfer of pollen
grains from anther to carpel
(think of bees ).
• Fertilization: fusion of male and
female gametes to form new
organism.
• Seed Dispersal: moving seeds
away from parent plant (reduces
competition) fertilized ovules
form seeds.
Baby Seed’s Parts and Needs
There are general conditions that all baby seeds need to germinate:
1. Water is need to rehydrate the dried seed tissues.
2. Oxygen is needed to allow aerobic respiration to produce ATP.
3. An appropriate temperature for the seed in necessary (import. for enzyme action).
How the Baby Seed Grows
• First things first IT HAS TO ABSORB WATER!
• Then metabolic changes occur.
• Gibberellin, or gibberellic acid, is released once the water is absorbed.
• This is a growth substance and it triggers the production of amylase.
• The amylase causes hydrolysis of starch into maltose. (The starch is already
there as a food reserve in the endosperm).
• Maltose then further hydrolyses into glucose that can be used for cellular
respiration or converted into cellulose by condensation reactions.
• The cellulose is necessary to produce the cell walls of new cells being produced.
Flower Control
• Photoperiodism is the plant’s response to light involving the relative
lengths of day and night, which is an important factor in the control of
flowering.
• To ensure continued existence in an area, a plant must flower when
pollinators are available and when necessary resources are plentiful.
Plant Type:
Flowering and Light:
Examples
Long-day Plants
Bloom when days are longest and
nights are shortest. (midsummer)
Short-day Plants
Bloom in spring, late summer, +
autumn when days are shorter.
Asters, Poinsettias
Flower without regard to day length
Roses, Dandelions
Day-neutral Plants
Lettuce, Spinach
PLANTO TIME!!!!!
• Guard Cells
• Abscisic Acid
• Transpiration
• Xylem
• Phloem
• Cambium
• Epidermis
• Pith
• Cortex
• Cuticle
• Palisade Mesophyll
• Spongy Mesophyll
• Stamen
• Carpel
• Short-day Plants
• Apical Meristems
• Lateral Meristems
• Auxin
• Pollination
• Fertilization
• Seed Dispersal
• Bulbs
• Stem Tubers
• Storage Roots
• Tendrils
• Phototropism
• Monocot. Plant
• Dicot. Plant
• Day-neutral Plants
• Long-day Plants
• A twirly stem modification.
• The tissue that produces primary growth, allows roots to grow.
• Happens when male and female sex cells unite to make a gamete.
• The loss of water vapor from leaves and other openings.
• The outer most layer that protects against water loss and insect invasion.
• The three female part of an angiosperm.
• Plants that flower without regard to day length.
• The central region of a root used for storage and support.
• A plant’s growth in response to light.
• Open and close the stomata.
• A plants that produces flowers with petals in multiples of threes.
• The transfer of yellow grains from anther to carpel. Buzz Buzz.
• Surround the vascular tissue in roots and stems.
• Bloom when the days are at their longest.
• Horizontally growing stems below ground. Potatoe.
• The tissue that produces secondary growth. FAT.
• Just above stomata allowing continuous channels for gas exchange.
•
•
•
•
• Carries water and dissolved minerals from the roots to the leaves.
• The hormone that causes positive phototropism.
• Bloom when the days are shorter.
• Has vascular tissue usually arranged in a ring.
Specialized cell within the root that store large quantities of carbs and water.
Carrot.
• The substance that causes guard cells to close stomata.
• The two male parts of an angiosperm.
• Moving fertilized seeds away from the parent.
The area of rapidly dividing cells that differentiate into xylem and phloem.
Located in a leave where the most light is avaliable, rich with chloroplast to
allow maximum photosynthesis.
• Surround the pith and helps with support.
Vertical, underground stems consisting of enlarged bases of leaves that store
food. Onions.
• The one thing I haven’t mentioned yet if we have still made it this far:
• transports organic nutrients throughout the plant.
INPORTANT INFO!
• I DID NOT, NOT, NOT, NOT
FULLY GO OVER 9.3.6,
9.2.11, and 9.2.1, I DID IT
TO SAVE TIME SORRY
GUYS.