Biodiversity Flashcards
Biodiversity
measure of the variation found in the living world
Species
individual organisms that are very similar in appearance, anatomy, physiology, biochemistry and genetics. So can interbreed freely to produce fertile offspring.
Species Richness
number of plant species
Species Evenness
the degree to which species are represented/ how evenly represented the species are (diverse if same amount of each)
Random sampling disadvantages
may not cover all areas of the habitat equally, species with low presence may be missed so underestimate biodiversity.
What is opportunistic sampling?
what are advantages?
what are disadvantages?
researcher makes sampling decisions based on prior knowledge of which areas contain particular species
easier and quicker than random
biased, large or colourful species may attract researcher, so overestimate
What is stratified sampling?
advantages?
disadvantages?
dividing habitat into areas which appear different and sampling each separately.
ensures all different areas are sampled
may over-represent some areas
What are types of systematic sampling?
advantages?
disadvantages?
line transects, belt transects
when habitat shows clear gradient in environmental factors like getting drier further from pond
only species on line or within belt are recorded, so underestimate
What to be careful with when sampling?
not cause disturbance to habitat
What is an interrupted belt transect?
use quadrat at set intervals along line
What is a continuous belt transect?
place quadrat beside line and move along line so study band/belt in detail
6 ways of catching invertebrates
sweep netting (with stout net, empty on white sheet)
pooter (collect animals before fly away)
knock the branch (white sheet under to catch)
pitfall trap (container in soil, contain little water/scrunched paper, in rain should be sheltered)
tullgren funnel (from leaf litter, light above drives animals down as litter dries/warms, fall through mesh to jar)
light trap (UV light attracts, eventually fall into jar containing alcohol)
How to trap small animals
may need license
Longworth trap (human trap, should monitor to release trapped animals)
enables mark-and-recapture technique
total population=no. 1st captured x no. 2nd captured
————————————————–
no. marked captured on 2nd
disadvantage of mark-and-recapture technique
animals may learn that trap is harmless and contains food, or may keep away from traps after first capture
Locus
the position of an allele (version of a gene) on a chromosome
Polymorphic gene locus
a locus that has more than two alleles
Simpson's index of diversity takes into account both... D is.. n is.. N is.. a diverse habitat will have a .. value
species richness and species evenness. D is the letter for it n is the number of individuals of a particular species N is the total number of all individuals high