Living Things in Nature Flashcards
Chapter 2, Pt 1
Who proposed the Five Kingdom Classification
R.H. Whittaker (1969)
-The kingdoms were defined as Monera, Protista, Fungi, Plantae, and Animlia
Kingdom Monera (Bacteria)
-Bacteria are the sole members of this Kingdom
How are bacteria Classified based on shape?
-Coccus (Cocci): Spherical shaped bacteria
-Bacillus (Bacilli): Rod-shaped bacteria
-Vibrium (Vibrio): Comma shaped bacteria
-Spirillum (Spirilla): Spiral shaped bacteria
What are bacterial modes of nutrition?
-Some may be autotrophic
-They may be photosynthetic autotrophic or chemosynthetic
-The vast majority of bacteria are heterotrophic
What are Archeabacteria?
Bacteria that live in some of the harshest habitats such as extreme habitats
What are Eubacteria (True bacteria)?
Bacteria that are chaterized by the presence of a rigid cell wall, and if motile a flagellum
What are Mycoplasmas?
-Organisms that completely lack a cell wall
What are the chatersistics of Kingdom Protista?
Protists are single-celled or unicellular organisms
-Made up of eukaryotic cells
-cell structure is complex with a well-defined nucleus
-Protophyta: Plant-like protists
-Protozoa: Animal-like protists
-Slime Mould: Fungi-like protist
Protists reproduce asexually and sexually by a process involving cell fusion and zygote formation
What are some charatersistics of Phylum Protophyta: Chrysophytes?
-Includes diatoms (microscopic single-celled algae) and golden algae (desmids)
-Found in freshwater and marine environments
-Most of them are photosynthetic
-Walls are embedded with silica.
What are Silica?
A protective outer covering made of Silicon Dioxide (SiO₂), highly durable and can perlite in sedimentary deposits for millions of years
What are the charteterstics of Phylum Protophyta: Dinoflagellates?
-Mostly marine and photosynthetic
-Cell wall has stiff cellulose plates on the outer surface
-Most of them have two flagella, one longitudinal and one transverse
Ex: Red Dinoflagellate, Gonyaulax
What are some charatersistics of Phylum Protophyta:Euglenoids?
-Freshwater organisms found in stagnant water
-Instead of a cell wall they have a protein-rich layer called a pellicle that makes their body flexible
-Have two flagella, long and short respectively
-Photosynthetic in the presence of sunlight
-Heterotrophs in the absence of sunlight
What are some charatersistics of Phylum Protozoa: Rhizopoda (Amoeboid Protozoans)?
-Live in freshwater, seawater or moist soil
-Move and capture their prey by putting out pseudopodia (false feet)
-Marine forms have silica shells on their surface
Ex: Amoeba
What are some charatersistics of Phylum Protozoa: Ciliophora (Ciliated Protozoans)?
Aquatic, actively moving organisms because of the presence of thousands of cilia
-Contain cavity (gullet) that opens to the outside of the cell surface
Ex: Paramecium
What are some charatersistics of Phylum Protozoa: Mastgiophora (Flagellated Protozoans)?
-Either free-living or parasitic
-Contain flagella
-Cause diseases like sleeping sickness
Ex: Trypanosoma
What are some charatersistics of Phylum Protozoa: Sporozoans (Sporozoan)?
Have an infectious spore-like stage in their life cycle
-Ex: Plasmodium (malarial parasite) which causes malaria
What are some charatersistics of Slime Moulds (Fungi like Protist)?
-Saprophytic Protist that moves along decaying twigs and leaves engulfing organic materials
-In suitable conditions, they form an aggression called plasmodium which may grow and spread over several feet
-In unsuitable conditions, the plasmodium differentiates and forms fruiting bodies bearing spores at their tip
-Spores are extremely resistant and survive for many years
What are some charatersistics of Kingdom Fungi (Mycota)?
-Prefer to grow in warm humid places
-Except yeast which are unicellular, fungi are filamentous.
-Their bodies consist of long, slender, thread-like structures called hyphae
-Some hyphae are continuous tubes filled with multinucleated cytoplasm called coenocytic hyphae
-Others have septate or cross walls in their hyphae
-Cell walls composed of chitin and polysaccharides
Fungal Modes of Nutrition
-Most fungi are saprophytes, heterotrophic fungi that absorb soluble organic matter from dead structure
-Parasites are fungi that depend on living plants and animals
-They can also live as symbionts in association with algae as lichens and with roots of higher plants as mycorrhiza
How does reproduction occur in fungi
-z-Reproduction can take place by vegetative means - fragmentation, fission, and budding
-Asexual reproduction is by Conidiospores, sporangiospores or zoospores
-Sexual reproduction is by zoospores ascospores and basidiospores
Kingdom Fungi: Phycomycetes
-Found in aquatic habitats and on decaying wood in moist and damp places
-Mycelium is aseptate and coenocytic
-Asexual reproduction takes place by zoospores (motile) or by aplanospores (non-motile)
-Spores are endogenously produced in sporangium
Ex: Mucor, Rhizopus (bread mould), Albugo (parasitic fungi)
What are the characteristics of Kingdom Fungi: Phylum Ascomycetes (Sac Fungi)
-Unicellular
-Saprophytic, decomposers, parasitic or coprophilous (growing on dung)
-Mycelium is branched and septate
-Asexual spores are conidia produced exogenously on the special mycelium called conidiophores
-Sexual spores are called ascospores and are produced endogenously in sac-like asci (singular ascus)
-Asci are arranged in different types of fruiting bodies called ascocarp
Ex: Aspergillus, Claviceps, Neurospora
What are the characteristics of Kingdom Fungi: Phylum Basidiomycetes
-They grow in soil, on logs and tree stumps, and in living bodies as parasites
-Mycelium is branched and septate
-No asexual spores
-Vegetative reproduction is by fragmentation
-Basidiospores are exogenously produced on the basidium
-Basidia are arranged in fruiting bodies called basidiocarps
Ex: Agaricus (mushroom), Ustilago (smut), and Puccinia (rust fungus)
What are the characteristics ofKingdom Fungi: Phylum Deuteromycetes (Imperfect Fungi)
-Known as imperfect fungi because only the asexual or vegetative phases of these fungi are known
no longer a true phylum
What are the characteristics of Kingdom Plantae?
-Includes all eukaryotic chlorophyll-containing organisms
-Few members are partially heterotrophic
-Have a eukaryotic structure, prominent chloroplast, and cell wall made of cellulose
-Includes algae, bryophytes, pteridophytes, gymnosperms, and angiosperms
What is Alternation of Generation ?
(also called haplodiplontic life cycle))
S biological process in which an organism alternates between two distinct multicellular stages:
Gametophyte (Haploid, n)
Sporophyte (Diploid, 2n)
What occurs durring the Sporophyte (Diploid, 2n) Stage?
Produces gametes (sperm and egg) through mitosis.
Gametes fuse during fertilization to form a diploid zygote.
What happens during the Sporophyte (Diploid, 2n)?
The organism Develops from the zygote and undergoes meiosis to produce haploid spores.
These spores grow into new gametophytes, continuing the cycle.
What are the charatersistics of Kingdom Animalia?
-Heterotrophic eukaryotic organisms, multicellular, and lack cell wall
-Digest their food in an internal cavity and store food reserves as glycogen or fat
-Mode of nutrition is holozoic by ingestion of food
-Sexual reproduction is by copulation of male and female followed by embryological development
Split into Invertebrata (creatures with no backbone) and Vertebrata (creatures with backbone)
What are Viruses?
Viruses did not find a place in classification since they are not truly ‘living’
-Non-cellular organisms
-Characterized by an inert crystalline structure outside the living cell
-once they infect the cell, they take over the machinery of the host cells to replicate themselves
-Inert outside their specific host cell (obligated protist)
What are Bacteriophages?
Viruses that infect bacteria
What are Viroids?
Free RNA that lacks a protein coat
Lichens
Symbiotic associations i.e. mutually useful associations between algae and fungi. The algal component is known as photobiont, and the fungal component as mycobiont, which are autotrophic and heterotrophic
-Algae prepare food for fungi and fungi provide shelter and absorb mineral nutrients and water for their partner
