Diversity of Living Things

...

Habitat- Mainly terrestrial

Nutrition- All fungi release enzymes externally

Absorb food/nutrients in four ways:

-Parasitic: Absorbs from living cells

-Predatory: have mycelia to trap prey

-Mutualistic: have partnership with other organisms

-Saprobial: feed on dead organisms

Plantae

TYPES OF PLANTS- bryophytes, trichophyte, gymnosperms, angiosperms

Bryophytes are limited in size as they lack tissues!!!!!!

Cell type- Eukaryotic

Structure- Multicellular

Cell walls composed of cellulose

Sessile

Antheridium: specialized structure on a gametophyte that

produces sperm

Archegonium: structure on a gametophyte that produces eggs

Sporangium: structure that produces spores

Gemma: photosynthetic haploid cells

Metabolism- Autotrophic

Reproduction- Cycle known as alternation of generations

Habitat- Mostly Terrestrial

Nutrition- Photosynthesis!!!!!!

Animalia

Cell type- Eukaryotic

Structure- Multicellular

No cell wall

Have nervous and muscle tissue

Very diverse otherwise

Metabolism- Heterotrophic

Reproduction- Sexual

Habitat- terrestrial and aquatic

Nutrition- ingests and digests food

Rise of diversity:

Prokaryotes→ Eukaryotes

Prokaryotes were only type of organism on earth for many years, until Eukaryotes evolved close to 2 billion years ago. The main theory about the creation of eukaryotes is the merger of two cells. This process is called endosymbiosis. The two organisms believed to be now called Eukaryotes are the mitochondria and chloroplasts.

Endosymbiosis

-Starts with two cells. One cell is engulfed by the outer cell, but the engulfed cell survives and becomes a part of the outer cell.

Algae→Plants

Viruses

-Viruses are small infectious structures that contains strands of DNA or RNA surrounded by a protective protein coat.

-Differ from prokaryotic AND eukaryotic cells in the following ways:

-Functionally dependent on host cells

-Structurally (not cellular, no organelles)

-dormant if outside of cells

-Not considered living

-Viruses are hypothesized to come from

-Small infectious cells that lost cytoplasm and reproductive abilities

-escaped pieces of DNA or RNA once part of living cells

-ancient particles existing even before first cells came about

-Viruses are not part of any of the 6 kingdoms used to classify living things

-classified on various characteristics including size shape and type of genetic material

-ALL viruses contain genetic material, and a capsid (protein coating)

-reproduction in viruses is either a) Lytic cycle, or b) lysogenic cycle

[pic 5]

- Lytic cycle-

- Virus binds to host cell and inserts genetic material

- DNA forms a loop

- DNA instructs host cell to make and assemble new viral components

- Host cell bursts open (lysis) releasing hundreds of new viruses

- Lysogenic cycle-

- Virus binds to host cell and inserts genetic material

- DNA forms loop

- DNA gets inserted into cell’s genetic material

- Can remain dormant for many cell generations

- When something in the cells environment changes it triggers viral DNA to separate, activate and enter the lytic cycle as above

Viroids

-Small infectious pieces of RNA

-Smaller than viruses with no capsid

-RNA does not code for proteins

-unknown how they cause disease, but research indicates they interfere with normal formation and functioning of hosts cell

-plant pathogens

Prions

-small abnormally shaped proteins

-animal (mammal) pathogens

-found in brain and nervous tissue of infected animals

-interact with normal proteins and change their shape

Dichotomous key

-used to identify organisms by using words and descriptions

Alternation Of Generations

[pic