Biodiversity and classification of micro-organisms Flashcards
Micro-organisms
organisms that can not be seen with a naked eye
Kingdom Prokaryotes
don’t have a nucleus
don’t have mitochondria, chloroplasts, and flagellae
very small
contain a cell wall made from protein like origin
Kingdom Eukaryotes
has a nucleus that is separated from the cytoplasm
nucleus contains chromosomes
some cells have flagellae or cilia
the cell wall consists of cellulose or chitin
Kingdom monera
bacteria are unicellular
widely spread by nature
mostly prokaryotes don’t have a true nucleus
reproduction is asexual binary fission
plays a role in maintaining soil fertility
some are pathogenic and cause diseases like TB
Kingdom Protista
consists of unicellular eukaryotes most are parasites feed off living organisms nutrition is mostly heterotrophic have a true nuclei live in almost any environment where water occurs as most portists are aquatic
Plasmodium falciparum (protista)
is a protozoan that causes malaria in humans and uses the adult mosquito as a vector
groups of organism
viruses
Bacteria
Protists
Fungi
The basic structure of viruses
- Viruses are very small
- Viruses consist of a central nucleic acid surrounded by a protein capsule
- Viruses can infect the plant, animal, or bacterial cells
- Viruses contain DNA or RNA
- Some viruses such as the flu virus and HIV are enclosed by a sheath of lipid and protein molecules
- Viruses are acellular and have no cytoplasm, cytoplasm, or organelles
- The shape of viruses varies from rod-shaped, spherical to a more complex shape
General characteristics of viruses
- Viruses are parasites that only reproduce within the living cells known as Obligate Intracellular parasites
- Viruses are host specific while some are tissue-specific
- Viruses reproduce by converting the genetic material (DNA or RNA) of the host cells into viral nucleic acids so that new viruses can produce
bacteria
- Bacteria are the smallest and simplest living organisms
- bacteria are classified under the kingdom Monera
- Some bacteria live in the presence of oxygen and are known as aerobic bacteria, while others can live in the absence of oxygen are known as anaerobic bacteria
- some bacteria are pathogenic and causes diseases
The basic structure of bacteria
- Bacteria are unicellular
- The bacterium cell is surrounded by a cell wall that consists of polysaccharides, proteins, and lipids
- In some bacteria, the cell wall is surrounded by a slime layer or capsule which protects the bacterial cell from enemies
- A plasma membrane occurs directly below the cell wall
- The cytoplasm has no membrane-bound organelles, such as vacuoles, plastids, mitochondria
- A true nuclei are absent
- Genetic material (DNA) is concentrated in a chromatin body known as the nucleoid
- Some bacteria move in a liquid called flagella
Shapes bacteria occur in
rod-shaped (bacillus)
round (coccus)
Spiral-shaped (spirillum)
comma-shaped (vibrio)
Characteristics of bacteria
- Bacteria are unicellular and simple
- Bacteria have no true nuclei and are prokaryotic
- Some bacteria are autotrophic and produce their own organic substances by photosynthesis
- majority of bacteria are heterotrophic
Reproduction occurs asexually by binary fission, where a single cell divides into two cells of identical DNA composition
three types of heterotrophic bacteria
Parasitic bacteria (obtain food from living organisms) Saprophytic bacteria( obtain food from dead organic material) Mutualistic bacteria ( when both benefit)
General characteristic of fungi
- yeasts are unicellular while mushrooms and moulds are multicellular
- All fungi have true nuclei and are eukaryotic
- All fungi have cell walls consisting of chitin
- All fungi consists of a mass of branched filaments or hyphae
- fungi have no chlorophyll and are heterotrophic
- some fungi are parasites
- most fungi are saprophytes and live off dead organic plant and animal
- Some live mutualistically with other organisms
Bacteria Role as producers in food chains in maintaining balance in the environment and food chain
Autotrophic bacteria and protists produce their own organic nutrients by photosynthesis and chemosynthesis and energy is stored in carbohydrates produced and it is available to the consumers
Bacteria Role as decomposers in food chains in maintaining balance in the environment and food chain
Decomposition bacteria fungi ad protists break down dead organic matter to their building blocks
Bacteria role in the nitrogen cycle
Free-living soil bacteria and nodule bacteria convert free nitrogen into nitrates and make it accessible to plants
how do viruses spread
Viruses spread through food, and vectors
life function of a virus
reproduction. A virus cannot be regarded as a cell as it does not have a nucleus with chromosomes material
biological importance of viruses
The virus is a Latin word for “poison”. Viruses cause disease and are therefore the main pathogens of plants as well as animals and humans
Habitat of fungi
fungi are present in any ecological habitat and live in a variety of growth media
The ecological and economic role of fungi
fungi play an important role in the breakdown and decay of dead animal and plant material
also play an important economic role. Crops can be destroyed by fungi causing large financial losses caused by parasitical fungi on animals that are much smaller than on plants. In humans, fungi cause oral thrush, athletics foot
ecological and economic importance of Protista
they are very important to the earth because they produce a lot of oxygen, and most living things need oxygen to survive
They form the base of aquatic food chains
They help keep the numbers of bacteria in balance with other organisms and they help break down dead plants and animals and recycle back nutrients into the environment
Cilia
responsible for movement and help to catch food. Ciliary animals are heterotrophic and each contains two nucleases per cell
