Unit 2 - Module 3 - Biodiversity And Evolution Flashcards
Define habitat
The place where an organism lives
Define species
A group of individual organisms very similar in appearance, anatomy, physiology, biochemistry and genetics, whose members are able to interbreed freely to produce fertile offspring
Define biodiversity
The variety of life.
It include all the different plant, animal, fungus and microorganism species worldwild, the genes they contain and the ecosystems of which they are a part.
Why can biodiversity be considered on a level of habitats?
In an area there are many different habitats, for example in woods, there are trees, rivers, the ground etc.
How can biodiversity. Be considered in a species level?
All species are different from each other.
Could be obvious structural difference or functional difference.
How can biodiversity be considered on a genetic level?
Variation between individuals belonging to same species.
Why cannot we be sure how accurate estimates on global biodiversity are?
Cannot be sure we have found all the species
New species are being found all the time
Evolution and speciation are continuing
Many species are endangered and some are becoming extinct
How many species is it estimated there are?
1800 000
How can you randomly choose the position of you sample sites inside a habitat?
Take sample at regular distances across the habitat
Use random numbers, generated by a computer to plot coordinates within the habitat
Select coordinates from a map of the area and use a portable Global Positioning System to find exact position inside the habitat
What is a quadrat and what is it used for?
A square frame used to determine the size of the sample area.
How do you use a quadrat?
Place it at random in the habitat.
Identify the plants found within the frame
Measure the abundance of the plants
How can you measure abundance of plants?
An abundance scale. Estimates abundance most common is ACFOR scale. Observe contents and apply scale to each species
Estimate percentage cover.
How can you estimate percentage abundance with a point frame?
Lower frame into quadrant record any plant touching the needles.
If it has 10 needle and is used 10 times. Each plant touching the needle will have 1% cover.
Why can you have a percentage cover of more than 100%?
One needs may touch several plants
What is a transect?
A line taken across the habitat.
Stretch a long rope or tape measure across the habitat and take sample along it.
What is an interrupted belt transect?
Use transect. Record plants touching the line at set interval along it.
Use quadrat at set intervals along the line.
What is a continuous belt transect?
Place a quadrat beside the line, and move it along the belt so you can study a band or belt in detail
How can you catch animals?
Sweep netting Collecting from trees A pitfall trap A Tullgren funnel A light trap
What is sweep netting?
It involves waking through a habitat with a stout net.
Sweep the net through the vegetation in wide arcs.
Any small animals will be caught in the net
Can empty the net into a white sheet to identify them
What is a pooter?
A device that is used to collect animals before they fly away
How can you collect from trees?
Spread a white sheet under a branch and knock it with a stout stick.
Vibrations caused dislodge and small animals, which then drop onto the sheet.
What is a pitfall trap?
A trap set in soil to catch small animals.
Consists of a small container buried in the soil so that it’s rim is just below the surface.
What is a Tullgren funnel?
A device for collecting small animals from leaf litter.
Place leaf litter in a funnel, the light above drives the animals downwards.
Fall through mesh to be collected in jar underneath the funnel
What is a light trap?
Consists of an ultraviolet light that attracts insects. Under the light there is a collecting vessel containing alcohol.
Why do we need to study a habitat?
Human activities affect the environment in a number of ways
Unless we study how our activities affect our environment, we cannot asses the effect we have.
EIA is used to estimate the effect of planned development
Sp we do not lose habitats or biodiversity.
How can we estimate species richness?
A qualitative survey
Take samples
How can we estimate the frequency of plants?
Use sampling techniques
Count number of plan te of each species per unit area, or measu percentage cover
How can you measure density of large animals?
Observe carefully and count the individual present
How can you measur the density of smaller animals?
Take samples
Mark and recapture technique
What is the mark and recapture technique?
Capture and mark a sample of animals. The number captured will be C1 .
Release them and leave the traps
Number captured second time will be C2
Number if already marks animals will be C3.
Total population = (C1 X C2) / C3
What does a high value of Simpson’s index indicate?
A diverse habitat.
Habitat tends to be stages and withstand change
What does a low value for diversity indicate?
A habitat dominated by a few species.
A small change could damage or destroy the whole habitat
Define biological classification?
The process of sorting living things into groups.
Natural classification does this by grouping things according to how closely related they are
It reflects evolutionary relationships
Define taxonomy
The study if the principles behind classification
Define phylogeny
The study of the evolutionary relationships between organisms
What are the five kingdoms?
Prokaryota Protocista Fungi Plantae Animalia
Prokaryotes
No nucleus A loop of naked DNA No membrane bound organelles Smaller ribosomes Carry out respiration not in mitochondria but on mesons ones Smaller than eukaryote cells May be free living or parasitic
Protocists
Eukaryotes Mostly single cells Wide variety of forms Plant like or animal like features Mostly free living Autotrophic or heterotrophic nutrition
Fungi
Eukaryotes Have a mycelium which consists of hyphae Walls of chitin Multinucleate Mostly free living and saprophytic
Plants
Eukaryotes Multicellular Cellulose cell wall Produce multicellular embryos from fertilised eggs Autotrophic nutrition
Animals
Eukaryotes Multicellular Heterotrophic nutrition Fertilised eggs that develop into a blastula Usually able to move around
Why do we classify things?
Convenience
To make study more manageable
Easier to identify organisms
Help use see relationship between species
What are the eight taxa in order?
Domain Kingdom Phylum Class Order Family Genus Species