Exam Flashcards
Do well on the exam (22 cards)
What is biodiversity?
The variety of all life in the world, plants animals and micro organisms, the genetic information they contain and the ecosystems they form.
Levels of Biodiversity?
Genetic diversity - The variety of genes within a species.
Organismal diversity - The variety of species within a habitat or region.
Ecological diversity - The variety of ecosystems within a given place.
What are the patterns of biodiversity and what explains these patterns?
Species vary globally - different yet ecologically similar, animal species inhabit separate, but ecologically similar, habitats around the globe.
Species vary locally - different yet related, animal species often occupy different habitats within a local area.
Species vary over time - some fossils of extinct animals were similar to living species.
What are the taxonomic groups?
Bacteria Viruses Kingdom Protista Fungi Kingdom Plantae Sponges Cnidarians Platyhelminthes Annelids Molluscs Arthropods Hexapoda - Entognatha, insecta Echinodermata Chordata Chonodrichthyes Osteichthyes Amphibia Reptilia Aves Mammalia
What are the six factors identified as primary causes of variation in species richness.
Evolutionary speed Geographical area Inter specific interactions Ambient energy Productivity Disturbance
Causes of extinction, and ways to conserve biodiversity?
Demographic factors Industry and urban development Agriculture Land use factors Grazing by feral and native animals Other human activities.
Biodiversity can be preserved in a number of ways including
What methods (direct vs. indirect) can we use to survey biodiversity?
Direct sampling - When the sample units are the actual members of the population. Eg: trapping and marking.
Indirect sampling - Sampling from documents or some record of the characteristics of a population, rather than recording of information obtained at first hand from units of the population themselves.
Survey - a study that collects information from a sample of individuals.
Census - a study which aims to collect data from every member of a population.
What types of information can we collect (index, census ect.)?
Morphology
Physiology
Abundance
Location
What are major threats to biodiversity?
Climate change Deforestation and habitat loss Over exploitation Invasive species Pollution
What is a press disturbance (threat)?
A gradual or cumulative pressure on a system
Ecosystem services ($)
Refers to a function humans rely on.
How might we conserve biodiversity?
Taxa/taxon based approach -
Threat based approach -
Spatially based approach -
Policy based approach -
Bacteria
Generally single cells with simple shapes
Prokaryotes - do not have membrane organelles within the cell, such as nucleus and mitochondria
A quite different life form to plants and animals
0.4 to 5 microns long
Viruses
Sub-cellular organisms
Only reproduce in the cells of their hosts
Many cause diseases in plants and animals
Each virus infects a particular host species
Kingdom Protista - Protists
Eukaryotes- cells contain several membrane lined compartments
Taxonomy not clear, kingdom Protista thought polyphyletic, ie. numerous evolutionary origins
Most are single called and live in aquatic environments
At least 100,000 species
Characteristics of Fungi
Most fungi grow as filamentous hyphae, microscopic filaments with tough waterproof cell walls
Body of the fungus consists of a mass of hyphae - a mycelium
Fungi reproduce by producing spores, single cells for multi celled structures adapted for dispersion and survival
Characteristics of Fungi continued
don’t photosynthesise, obtain energy from organic matter
- primary decomposers of organic matter
- secrete enzymes and other substances to assist with external digestion
- saprophytes – live on dead organic matter (e.g. rotting wood, leaf litter – important role in nutrient cycling)
- parasites – live on other living organisms
- mutualists – live in partnership with other organisms
Characteristics of plants
plants are everywhere and a part of everyday life
- critical contributions to human wellbeing – food, shelter, aesthetic pleasure
- photosynthetic organisms - (convert light energy to chemical energy and biomass)- ~1/5 of all living organisms able to create energy and provide energy for others using light (CO2 and H2O is pretty damn funky!)
- we use ~1/4 of all global net primary production!
- all land plants are multi-cellular and their cells have specialised to form different types of tissues and organs
Sponges (Phylum Porifera)
aquatic animals
- mostly marine
- ~5000 species
- only animal in which cells not organised into tissues or organs
- no mouth, gut, circulatory or nervous system
Characteristics of animals
multi-cellular - differentiation into tissues and organs for different functions
- embryonic development - individual develops from single-celled zygote
- heterotrophs - feed on other organisms
- mobile - during at least some stage of life cycle
Cnidarians (Phylum Cnidaria)
includes sea wasps, jellyfish, sea anemones, hydrozoans and corals
Two main forms:
•polyp and medusae stages
- polyps (attached, tubular, mouth upward)
- medusae (free floating, mouth downward)
- radially symmetrical
- marine and freshwater
Types of Cnidarians
Scyphozoa(jellyfish)
- main life-cycle phase is the floating medusae (jellyfish)
•Cubozoa(box jellyfish)
- includes the sea wasp – stings can be fatal to humans
- Hydrozoa - mostly occur as polyps living colonially
- Anthozoa- sea anemones, corals
