PLANT BIO
2 Types of Cell Division


Mitosis – Results in 2 genetically identical daughter cells.
Meiosis – Results in (up to) 4 daughter cells that are genetically different from the
mother cell = have half the # of chromosomes.
Homologous Chromosomes – (of the same type)


Diploid Cell (2N) – 2 copies of each type of chromosome
Haploid Cell (N) - Has 1 copy of each type of chromosome
Sporophyte Gen.
2N
N
2N
Gametophyte Gen.
Mitosis=
sperm /egg
cells
Zygote
Asexual Reproduction: w/o sex – new individuals are produced by mitotic cell divisions.
Sexual Reproduction – involves the fusion (syngamy) of gametes of opposite mating types to produce a
zygote.
In flowering plants Meiosis and syngamy takes place within the flower.
What is a flower?
Flower is considered to be a very specialized shoot, consisting of a stem (=floral axis) that bears modified
leaves (=floral appendages).
Floral Structure
-flowers consist of a receptacle (=floral axis) that bears floral appendages (=modified leaves) often four
types of floral appendages.
1. Sepals (=collectively called the calyx)
a. Lowermost floral appendages
FUNCTION: to protect the developing floral bud.
2. Petals (= collectively the corolla) – situated above the calyx
FUNCTION: Attract pollinators.
3. Stamen (=collectively the androecium)
a. Located just above the petals
b. Consist of an anther born on a filament
FUNCTION the anther is one of 2 places within a flower where meiosis takes place.
Meiosis results in the formation of microspores (N)
Microspores will divide by mitosis to form microgamytophytes and male gametophytes
(pollen grains)
4. Pistils (= Collectively the gynoecium)
a. Located in the center of the flower.
b. Consists of a stigma, style, and ovary.
The ovary contains ovules.
FUNCTION: The ovules are the second site of meiosis within the flower. Meiosis results
in megaspores (N).
Megaspores divide to form mega gametophytes and female gametophytes



1)
2)
3)
4)
Pistils are formed from CARPLES = Modified Leaf
A Simple Pistil forms from 1 carpel
A Compound Pistil forms from 2+ carpels.
Color
Size
Oder
Shape
a. Radial Symmetry very many flowers) 2+ axis of symmetry.
b. Bilateral Symmetry 1 axis of symmetry.
5) Number of appendages/ series (sepals, petals, etc.)
a. Numerous
b. Reduced to a fixed #
c. Multiples of 3 are common amongst monocots
d. Multiples of 4 or 5 are common amongst dicots
e. Absence of one or more floral appendages:
i. “imperfect flower” where the stamens or pistils are absent
1. Stamenate flowers lack pistils
2. Pistillate flowers lack stamens
Monecious Plants – form stamina and pistil flowers on the same individual.
Dioecious Plants – form stamina flowers on one individual as well as a second individual.
6) Fusion
a. Free (ancestral condition)
b. Examples
i. Sepals- Calyx Tube
ii. Petals- Corolla Tube
iii. Carpels – Compound Pistils
iv. Ovaries with the receptacle – inferior ovary
INFLORESNENCE (look at notes for pictures)
-special modified portions of the shoot system that bear flowers
Receme, Spike, Panicle, Umbel, Head,
Sunflowers are Composite flowers – they have disc flowers and ray flowers which = a modified head.
Meiosis takes place in Anther and Ovule
Sporangium – structure that forms spores.
Microsporocyte – Microspore mother cell
Pollen Grain to Micro gametophyte = Gametophyte
A bit about the seed
Ovule forms the seed.
Ovary wall forms fruit wall = pericarp
Integuments form the seed coat.
The multicellular diploid stage of a plant life cycle is called the : SPOROPHYTE
List two places in a flower where meiosis takes place: ANTHER AND OVARY
What is the function that is associated with petals? TO ATTRACT
The sepals of a flower collectively make up the: CALYX
Any plant species in which one type of individual bears staminate flowers and second type of individual
forms pistillate flowers is described as being: Dioecious
Most monocots either have numerous floral appendages of each type, or the number of floral
appendages reduced to a multiple of : THREE
Members of the sunflower family bear their flowers in modified heads, each consisting of a combination
of disc flowers and ray flowers, These heads are called: Composite
In order for pollination to occur, a pollen grain must land on the: STIGMA
During double fertilization, on sperm fuses with the egg cell to form: ZYGOTE
And second sperm fuses with the two polar nuclei to form: ENDO SPERM
Which portion of a flower develops into a fruit following fertilization: OVARY
Which portion of a flower develops into a seed following fertilization: OVULE
Individuals that are formed by asexual reproduction are called: CLONES
Which fruit type includes mangoes, peaches, and apricots? DRUPE
TRANSPORTATION
1) Diffusion: spontaneous movement of atoms, ions, molecules from region of high
concentration to region of lower concentration.
a. Important for dispersal of molecules/ solutes within the cell.
b. Account for the movement of some molecules into and out of the cell through te
plasma membrane.
Solvent + Solute = Solution
2) Osmosis: Diffusion of water through a selectively permeable membrane. (= permits the
movement of water but not most soluble).
a. Plasma membrane is selectively permeable
b. All organisms live in an “osmotic environment”
3 Types of Osmotic Environment
1) Isotonic Solutions: has the same solute concentration inside cell as it does outside of cell.
a. Solutes does not pass through. It stays at an equilibrium.
2) Hypotonic Solution: lower concentration of osmotically active solutes than the cell.
a. Turger Pressure
3) Hyper Tonic Solution: higher concentration of osmoticaly active solutes than the cell.
Water Potential
Combination of the factors which determine the movement of the water.
1) Osmotic Potential – measuring the tendency for water to move from high concentration to low
concentration.
2) Pressure Potential – tendency for water to move from region of higher pressure to region of low
pressure
3) Matric Potential – tendency for water to be attracted to changed surfaces. (Adhesion)
Active Transport
Movement of solutes through the membrane by carrier protein against the concentration
gradient using cellular energy (ATP)
Protein change shape. Protein makes a tunnel for solutes to go through.
ATP – stores energy in chemical bonds.
ATP – ADP + P = Energy
Connetic Energy is Movement
Long Distance Transport
Xylem: conducts water + minerals
Conducting Cells: Tracheid’s
1) Cohesion Tension: elements Mechanism
2) Root Pressure – usually a miner mechanism, but be important.
Phloem: sugar + organic molecules
Conducting cells: sieve tube members = companion cells
1) Pressure Flow Mechanism – in leaf phloem loading takes place = active transport of solutes into
the sieve tube members.
Root – phloem loading takes place – sugars are emerged from the phloem and water moves passively
PHOTOSYNTHESIS (biochemical pathway)
-takes place in the chloroplast.
2 sets of reaction
Dark Reaction – takes place in stroma
-
Color fixion reaction
Fixed in reactions
Co2 incorporated into simple organic molecule.
Food.
Energy + ADP = Glucose
Light Reaction – kinetic energy = PHOTONS (tiny particles of energy)
-
ATP & NADPH
Electromagnetic energy – EM spectrum of energy is what plants need (ROYGBIV)
NON CYCLIC PHOTOPHOSPHARYCLATION
1)
2)
3)
4)
Uses both PSI and PS2 and the entire E.T.C
New 3- are made available by photoysis
Requires light and water
Forms: ATP, NADPH, O2
CYCLIC PHOTOPHOSPHARYLATION
1)
2)
3)
4)
Uses PS1 and most of the E.T.C
No H2O split (photoysis stops)
Requires light
Forms: ATP
What is the enzyme of a pigment? RIBISCO!
Under certain conditions, RIBISCO malfintions and acts as an oxygenase rather than a carboxylase
-
This results in a loss of fixed carbon (and ATP) form the cell.
This occurs when O2 is high and Co2 are low.
C4 Cycle
Briefly define diffusion: spontaneous movement of atoms, ions, and molecules from the higher
concertrations to lower concentrations.
Diffusion of water through a selectively permeable membrane is called: Osmosis
Solutes are moved into plant cells by an ATP requiring process called: Active Transport
The major mechanism for the flow of water up a stem through the xylem is called (transpirational
pull) Cohesion Tension.
The mechanism for the flow of water and sugar through the phloem of a plant from sorce to sink is
called: Pressure Flow
The overall purpose of photosynthesis for a plant is to form: Glucose
Wher do the light reaction of photosynthesis take place? Thylakoid
Where do the dark reactions take place? Stroma
P680 and P700 are special reaction center molecules of the pigment: Clorophyll A
Plants us the C3 cyle to fix carbon. Breifly explain what this means:
Water pushed up into the leaves by root pressure may be released through hdathodes. This process is
called: Glutation
What is the name of the enzyme that fixes carbon during the C3 cycle. RIBISCO
PLANT DIVIRSITY
Bryophyte Divisions:
Dominant Gametophyte= gametophyte is “green”, free living, and is perennial.
Sporophyte Generation= “reduced”, and short-lived and nutritionally dependent on the gametophyte
“Non Vascular Plants”. Lack tissues and organs. Reproduction is “free-sporing” = spores are released to
the environment.
1. Bryophyta (mosses) – large and diverse division. Name to know: rhizoid. (Know antheridium is
the holder for sperm and then the sperm moves to arkygonium where it forms the zygote)
Random: Sphagnum Moss
2. Hepaticophyta (liverworts) – may be leafy or thalloid. – sporophytes are ephemeral (disappear
quickly)
3. Anthocerotophyta(hornworts) – thalloid. Large and diverse group of free sporing vascular
plants. Sporangia are formed on the lower surface of special leaves = sporophylls
They All (below) are Vascular Plants (Tracheophytes)
 Have xylem + phloem and other tissues
 Have organs: stems (and usually) roots and leaves
 Have dominant sporophyte generation (gametophyte is reduced)
Free-sporing vascular plants: sporophytes. Release their spores to the environment.
Both sporophyte and gametophyte generations are free living. Gametophytes are small and usually
short lived
4.
5.
6.
7.
Psilotophyta (whisk fern)
Lycophyta (lyco pods)
Equisetophyta (horsetails)
Polypodiophyta (ferns)
Seed Plants (spermatophytes) – heterosporas. Has microspores that form pollens. And megaspores are
in the ovules .
Non Flower seed Plants (gymnosperms) - form pollen in cones – mostly they form ovules in cones (or
sporangiophones)
8.
9.
10.
11.
Pinophyte (conifers)
Cycadophyta (cycades)
Ginkgophyte (ginkgo biloba)
Gnetophyta (gnetophytes)
Form pollen and ovules in flowers which are formed in a fruit.
12. Magnaliophyta (flowering plants)