GRADE 11 MICROORGANISMS

classifications of living

movement

respiration

sensitivity

growth

reproduction

excretion

nutrition

Viruses

non-living

no cells, nucleus, cytoplasm or oganelles

don't perform metabolic processes

pathogens that cause disease

known as obligate intercellular parasites

How do viruses reproduce

by converting the DNA/RNA of the host cell into viral nucleic acids so that new viruses can be produced

virus structure

simplistic in form and small

consist of a central nucleic acid surrounded by a protein capsule

contain either DNA or RNA

acellular

Bacteria

single-celled microbes (prokaryotes)

no nucleus or membrane-bound organelles

center of control containing their genetic information is contained in a single loop of DNA

majority are heterotrophic

Aerobic bacteria

require oxygen to live

Anaerobic bacteria

lives in the absence of oxygen

Bacteria reproduction

occurs asexually by binary fusion where a single cell divides into two cells of identical DNA composition

Bacteria structure

unicellular

surrounded by cell wall

cell wall is sometimes surrounded by a slime layer or capsule

plasma membrane directly below cell wall

some move in liquid with the help of flagella

Protists

unicellular or multicellular

heterotrophic (except for algae which is autotrophic)

reproduction occurs mostly sexually by binary fusion

live where water occurs

Protist structure

have various locomotory structures (pseudopodia, cilia, flagella)

cell wall composition varies

algae contains chloroplast

Macroscopic fungi

fleshy fungi with visible bodies

Microscopic fungi

unicellular yeast or multicellular threadlike molds

Fungi

most are saprophytes

reproduction occurs asexually by binary fision (unciellular) or by means of gametes during unfavorable conditions (multicelllular)

Fungi structure

hyphae are interwoven to form mycelium

they are branched and have no crossed walls (aseptate)

each hyphae (coenocyte) contains a cytoplasm and a large number of nucleus

3 types of hyphae

runners/stolons - branch horizontally on surface of substrate

rhizoids - branches of the stolon that penetrate the substance and anchor the mycelium

sporangiophore - hypha that grow vertically and develop sporangia

Role of viruses in the environment

bacteriophage controls bacteria populations

Role of nitrifying bacteria in environment

use inorganic chemicals (amonia and nitrites) as a source of energy and convert harmful substances into useful substances for other organisms

aerobic and autotrophic

Role of bacteria in environment

Form mutualistic relationships with other organisms such as E-coli in the gut that helps digest cellulose

Role of protists in environment

plankton forms the basis of all ocean food webs, produce oxygen and absorbs carbon dioxide

Role of fungi in environment

decompose dead organic matter, unlocking the nutrients inside which are then reused in fertilized soil and by other living organisms

Recombiant DNA

form of genetic engineering whereby scientists insert a specific gene from a human cell into the DNA of another organisms (bacteria)

Bioremediation

form of biotech that uses microorganisms to neutralize/remove/consume toxic substances in various environments