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

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