Vascular Plants

Vascular Plants (Phylum Tracheophyta)

• Tracheids - Specialised cells for conducting water and supporting tissues (forming the xylem vessels)
• All SPOROPHYTES in this group are larger than the gametophytes and have ROOTS, STEMS AND LEAVES.
• can be further sub divided into the non- sees tracheophytes and the seed plants

THE SPERMATOPHYTA 'Seed Plants';

Now represented by two Phyla:

- The Gymnosperms:
 ( Cycads, Gingkos, Gneetophytes, Confiers)

- Angiosperms
 (Magnoliphyta or flowering plants)

COMMON THINGS IN ALL SEED PLANTS;

• Seeds
• Reduced Gametophytes
• Heterospory: Spored of two different sizes and sexes
• Ovules: Female gametophyte, protected by tissues of sporangium
• Pollen: Male Gametes (Sperm cells)

THE ALTERNATION OF GERNERATION IN THE SPERMATOPHYTA;

 

• The gametophyte generation is reduced to a very small, simple stage (only a few cells!).

• The gametophyte develops partly or entirely whilst it is still nutritionally dependent on the sporophyte. 

Non Vascular Plants

Non Vascular Plants (Non- Tracheophytes): Bryophytes 

Main Features; 

• The group are largely confined to damp conditions which allow the passage of sperm to the archegonia and the flow of nutrients to individual’s cells. 

• Non- Vascular plants have recently been divided into 3 phyla which are started below (Originally one Bryophyte) and are classified according to the shape and the growth pattern of the sporophyte 

• They DON’T PRODUCE SEEDS due to them nurturing their zygotes in the tissues of the parent plant.

• They rely on the surface film of water to act as a transport system as tracheophytes are not huge plants therefore do not develop a transport system, so film of water transports all the nutrients which enters by diffusions. Some can tolerate very dry conditions but still relay on a moisture film for growth and reproduction.

Examples of Non vascular plants

Bryophyte (Mosses)

Formerly Class: Bryopside (musci)

First Fossil to date back 415 Mya.

Ø  Differentiated into simple leaf- like structures that can form stems

Ø  Some species with cells called hydroids which ‘die’ and become tubes through which water can pass- first origins of transport systems.

Ø  There are not lignified* but are otherwise analogous to xylem in the vascular plants.

Sporophyte is stalked with a spore capsule 

Hepatophyta (Liverworts)

Formerly class: Hepaticopsida

Thought to have been the first to evolve.

Ø  Some are leafy and prostrate, other are plate-like.

Ø  Sporophyte is not stalked (Although gametophyte which bears it may be)

Ø  Rhiziods (‘Rootlike structures’) are unicellular filaments

Anthocerophyta (Hornworts)

Formerly class: Anthocertopsida

Ø  Gametophytes always thalliod (not differenced into steam or leaf)

Ø  Sporophyte* stalked with needle like capsule- capable of indefinite growth.

Ø  Process stomata and form mutualistic relationship with cyanobacteria*

Form some of the largest non-tracheophytes- up to 20cm 

*SPOROPHYTE; is the diploid multicellular stage in the life cycle of a plant or alga. It develops from the zygote produced when a haploid egg cell is fertilized by a haploid sperm and each sporophyte cell therefore has a double set of chromosomes, one set from each parent.

*CYANOBACTERIA:  bacteria but are capable of photosynthesis. 

*LIGNIGIED: make rigid and woody by the deposition of lignin in cell walls.

LIFE CYCLE

Life Cycle Haploid/ Diploid Stage; Alternation of the generations between haploid gamete- producing Gametophyte and diploid spore-producing sporophytes, the gametophytes being the more prominent of the two

Life cycle of Non Vascular plants from Life, the science of biology

Sporophytes attached to the, and derive nourishment from, the gametophytes.

-          Male gametes (Mobile) are produced in an ANTHERIDUM

-          Female gametes are produced in an ARCHEGONIUM

Ø  The male swims in a surface film of a water and fertilise the female egg in situ. After syngamy, the sporophyte grows out of the gametophyte and derives its moistures and nutrients from it.

Remaining attached to the gametophyte throughout its life

Domain Plante (Basics)

Definition; 

‘A multicellular, Photosynthetic, eukaryotic organism (includes some algae)…which includes develops from the embryos protected by tissues of the parent plant” (all land plants)

THE LAND PLANTS; 

10 major clades;

•           Three clades have no system of conducting fluids- calling the Non- Vascular Plants or Non Tracheophytes
• 
  
•           Seven Clades have well- developed fluid transport systems based on cells called TRACHEIDS/ TRACHEOPHYTES

Divided into:

•       Non-vascular plants

•       Vascular land plants:

                - Non-seed plants

                - Seed plants:

                                >Gymnosperms

                                > Angiosperms

Domain Protista

The Kingdom Protista are a ‘paraphyletic’ group!

(Paraphyletic = consists of all the descendants of the last common ancestor of the group's members)

 

The Basics;

Mobile or stationary

 Most are unicellular, some multicellular

Autotrophs or heterotrophs, or both.

 

 

A mobile Protista

Both ASEXUAL and SEXUAL reproduction

Simple plasma membrane or stiffer structure (cell wall, internal shell)
Many contain endosymbionts

CHARACTERISTICS;

• Moist habitats
• Many single celled, some clonal, some multicellular (or colonial)
• Some mobile, other stationary
• Important in nitrogen cycling and in various carbon and nitrogen cycles
• Some important human parasites and pathogens

 

GROUPING;

Often grouped by ecological role;

1. Algae
2. Protozoa
3. Fungus- like

CLASSIFICATION BY BROAD 'SUPERGROUPS'

Excavata
Archaeplastida
Euglenozoa
Rhizaria
Stramenopila
Amoebozoa
Alveolata
Opisthokonta
Chromalveolata etc.

Movement;

Attached to surfaces and mobile;
Free-floating species sometimes grouped together as the plankton

• Ciliates: ciliated, move using cilia
•  Flagellates: flagellated, move using flagella
• Amoeboid: amoebae, move using pseudo-podia
• Slide, using carbohydrate or protein slime

 

Chlorophyta

Is one of the largest groups of green algae. Most aquatic, some terrestrial.

Pediastrum boryanum

Domain: Eukaryota

Kingdom: Protista

Division: Chlorophyta

Class: Chlorophyceae

Order: Chlorococcales

Family: Hydrodictyaceae

Genus: Pediastrum

Species: Pediastrum boryanum




Origin of different morphologies and multicellular bodies.....

Pediastrum boryanum

The prokaryotic Cell

Species definition;
"population of cells with similar characteristics"

Cell wall;
- Peptidoglycan
- Outer membrane

The DNA of Bacteria is contained in a circular chromosome, folded into many loops

Bacteria have both a plasma membrane and cell wall

Bacteria often have a small circles of additional DNA called plasmids.

SHARED CHARACTERISTICS

1. Plasma or cell membrane
2. Nucleoid
3. Cytoplasm; Cytosol + Insoluble Particles
4. Ribosomes

DISTINCTIVE CHARACTERISTICS

1. Cell walls
2. Capsules
3. Internal membranes
4. Flagella
5. Pili
6. Fimbriae
7. Cytoskeleton

PLASMA MEMBRANE;
is a selective barrier enclosing the cell that separates the interior and exterior of the cell from the environment. It is semi permeable, it allows gases, nutrients and waste in and out of the cell. (Bilayer of Phospholipids with proteins attached to or embedded in it)

NUCLEIOD;
The region in the prokaryotic cell where DNA is located

CYTOPLASM;
Composed of cytosol; mostly water and soluble particles

RIBOSOMES;
complex of RNA and proteins which function as sites for proteins synthesis (RNA-PROTIENS)

CELL WALL;
Outside the plasma membrane, bacteria contains peptidoglycan that covers the entire cell:
- gives rigidity
- Support and shape

CAPSULE;
layer of polysaccharides enclosing the cell wall.
protects the bacteria from the immune function and desiccation, also helps attachment

INTERNAL MEMBRANE;
A system of folded bilayer membrane that contains molecules needed for;
- Photosynthesis
- Cell division
- energy releasing reactions

FLAGELLA;
Corkscrew- like appendage used for movement.
composed of flagellin and protein ring structures anchored in plasma membrane forming a rotor

PILI;
Hair like structure, shorter then flagella.
Made of protein projecting from the surface of many bacteria
Used for adherence.

FIMBRIAE;
Shorter then the pili.
Used for adherence to animal cells, food and protection

CYTOSKELETON;
Network of filaments structures, extends length of cell.
Inside the plasma membrane. present in rod shape Bactria (E.Coli)

The Domains

Correct me if I am wrong.... but there are 3 main domains in the 'tree of life'

1. Eukaya
2. Archea
3. Bactria

As stated above this are the main 3 domains... lets go into a bit more depth.

DOMAIN EUKAYA;
This domain contains 4 more domains within it;

1. Protista
2. Fungi
3. Plante
4. Animalia

DOMAIN ARCHEA;

These are only found in the most EXTREME ENVIRONMENTS:

·         Hot springs

·         Anerobic or microaerophilic conditions

·         Sulphurous Volcanic upwellings

·         Extremely saline conditions

·         High alkalinity

·         Extremely acidic conditions

 

Phylum: EURYARCHAEOTA

·         Metgangens

·         Obligate anaerobes producing methane

·         Some are also extreme thermophiles

·         Extreme Halophiles

·         Some use Bacteriorhodopsin to photosynthesis

 

Methanobrevibacter smithii

Domain: Archaea

Kingdom: Euryarchaeota

Phylum: Euryarcheota

Class: Methanobacteria

Order: Methanobacteriales

Family: Methanobacteriaceae

Genus: Methanobrevibacter

Species: M. smithii

 

Phylum: Crenarchaeota

-          Extreme acidophilic and/or thermophiles (often found at volcanic vents)

-          E.g Thermus aquaticus= taq polymerase used DNA amplification

-          Some can survive pH 0.9 and >70 degrees

Sulfolobus acidocaldarius

Domain: Archaea

Kingdom: Crenarchaeota

Phylum: Crenarchaeota

Class: Thermoprotei

Order: Sulfolobales

Family: Sulfolobaceae

Genus: Sulfolobus

Species: Sulfolobus acidocaldarius
 

DOMAIN BACTERIA;

Phylum: Proteobacteria

·         Gram negative

-          Negatively charged cell wall:

       Helps evading Phagocytosis

       Physical Barrier

·         Largest Number of species:

-          E.coli, salmonella, vibrio, Helicobacter

-          Anaerobic, Chemoautotrophs, photoautotrophs, heterotrophs

-          Beneficial symbionts

-          Pathogens

Example;

ESCHERICHA COLI (E.COLI)

Domain: Bacteria

Phylum: Eubacteria

Class: Protebacteria

Order: Gammaprotebacteria

Family: Enterobacteriace

Genus: Escherichia

Species: E.Coli

Phylum: Firmicutes

·         Gram positive, with cell wall containing teichoid acids

·         Teichoid acids:

-          Movement of cations in/out of the cell

-          Antigenic specificity

-          Some produce extremely persistent endospore e.g. anthrax, tetanus

·         Actinomycetales are filamentous bacteria

·         Superficially resembling fungi

·         Important component of the soil microbiota

·         Some serious pathogen, e.g. Mycobacterium

·         Produce many antibiotics, e.g. Streptomycin group

STAPHYLOCOCCUS ALBUS (S.ALBUS)

Domain: Bacteria

Phylum: Firmicutes

Class: Cocci

Order: Bacillales

Family: Staphylococcaceae

Genus: Staphylococcus

Species: Staphylococcus Albus