Biology Unit 3 Flashcards
Biological Classification
-grouping of organisms and ecosystems based on similarities.
-Taxonomy
-Hierarchy of groups (taxa) based on similarities.
-allows international standardisation.
Taxonomy
grouping and naming of organisms
Linnaean system
-classifies similarities in physical features
-organised into hierarchal groups, successive level, smaller and more closely related than the one before.
Order of Linnaean system
Kingdom
Phylum
Class
Order
Family
Genus
Species
Broad taxa
Many organisms which share a few major similarities. e.g. Animal: eukaryotic, Multicellular, Heterotroph, levels of cell specialisation.
Narrow taxa
group of organisms sharing many specific features.
Binomial nomenclature is..
-Organism’s scientific name—-two words.
Genus —-> Starts with capital
Species—-> lowercase, italics or underlined
Limitations of Linnaean system
-doesn’t account for molecular evidence
-Genetic similarities more accurately show evolutionary relationships, than physical similarities.
Methods of reproduction
-Asexual reproduction
-Sexual reproduction
Asexual reproduction is
-Single parent—> No gametes
-No genetic diversity
Sexual reproduction is
-two parents —> (gametes: eggs & sperm)
-genetic diversity
r & K selection
reproductive strategies
traits that determine the quality and quantity of offspring.
R - strategists
quantity = no.
Short lifespan, high rate of reproduction, maturing rapidly
Little to no care of young
Inhabiting changing environments.
Eg. insects, spider, rodents, bacteria
K - strategists
Quality = Survival
-long lifespan, low reproduction rate, maturing slowly
-care for their young
-Eg. most mammals, reptiles like sea turtles
Molecular phylogeny (Evolutionary past)
-genetic definition of species
-amount if genetic variation = base pair sequence/ no. of genes/ no. chromosomes
- to determine evolutionary relationships.
Molecular clocks
-changes in DNA sequences occur due to mutations
-use mutations to estimate evolutionary time
-Mutations add up at a constant rate in related species
-The greater the similarity, the more recent the evolutionary past
Amino acid sequencing
Closely related species, similar amino acid sequence, therefore similar gene for that protein.
Degree of similarity = number of mutations
DNA sequencing
Identify similarities in DNA samples by determining the exact number of nucleotide differences
Species interactions
Organisms interact, biotic & abiotic environment
Biotic = each other
Abiotic = their surroundings autotroph —> photosynthesis
PCDS(CAMP)
-Predation
-Competition
-Disease
-Symbiosis
—->Commensalism
—->Ammensalism
—->Mutualism
—->Parasitism
Predation
One organism, predator, kills & consumes another organism
Competition
Fight with another organism for the same resource
-Interspecific: between diff species
-Intraspecific: Between same species
Disease
Non-infectious
Infectious
Pathogens
Host
Vectors
Symbiosis
Long-term interaction between two diff species, at least one is affected : CAMP
CAMP
Commensalism
Ammensalism
Mutualism
Parasitism
Commensalism
One benefits, other is not harmed
Eg. Barnacles on whale
Ammensalism
One species accidentally harms other, but does not benefit
Eg. Cows trampling on grass
Mutualism
When bother species benefit
Eg. A shark and a little cleaner fish attached to the shark
Parasitism
Lives in or on & feeds upon, not kill
Eg. Tapeworm inside the body
Species
group of similar organisms that are capable of reproducing, fertile, viable offspring
Individual
one of a species
Community
all the species in the same area & their interactions
Population
group of individuals of the same species in same area at the same time
Environment
Area in which organisms live
Ecosystem
all living things within a environment & their interactions with each other (Biotic factor) and their interactions with the physical environment (abiotic factors)
Biotic factors
interactions between species PCDS[CAMP]
Abiotic factors
environment = water, light, soil, topography (slope)
Vegetation Zones
areas with similar types of plants, indicate abiotic factors (esp. temp, rainfall & altitude)
Habitat
place where an organism lives
Microhabitat
a small, specific area within a larger ecosystem that has its own unique set of environmental conditions & organisms.
Ecoregion
large ecological regions characterised by specific ecological patterns (climate conditions) made up of a number of habitats.
Biome
region of earth characterised by climate and dominant plant species
Biodiversity
describes the variety of range of all lifeforms (species), the genes they contain & the ecosystem of which they are a part of.
Species Diversity
no. of different species
Genetic diversity
refers to the variety of genes within a species gene pool
Ecosystem diversity
refers to variety of ecosystems found in large area [continent or globally]
Classifying ecosystems
important for management & conserve, to maintain biodiversity, preventing extinction.
Ecosystems are independent
Spechts
structural features of plants - foliage cover & plant hieght
Holdridge
plant formations, climate: humidity, precipitation, & evaporation.
Ecosystem management (productive soils)
Soils (pH, porosity (space between soil particles), structure, salinity, nutrient contents & depth) determine the distribution & abundance of plants and therefore animals
soil management
-water runoff & erosion
-porosity = ability to hold water
-compaction affects porosity
-essential for sustainable farming
old growth forests
-Many microhabitats
-Store carbon
-slow decomposition
-slow turnover (stored in biomass then released by respiration)
- storing carbon in plant matter
-Slow growing
Sampling
representative of the population
-random
-systematic
random sampling
-each member has equal chance being selected
- homogenous environment eg. oval, desert, beach dune, grassland
-random number tables or generators
systematic sampling
-environmental gradient
-Transects used along environmental gradient (abiotic factor changes over distance)
Define stratefied sampling
-breaks a large population into similar subgroups (strata)
-samples randomly taken from each strata
-used in habitats where areas are identified as being very different from eachother & used to be sampled separately
purpose for sampling
what info is required?
-Population
-Environmental
-Site selection
Purpose for sampling (population)
-size
-density
-distribution
Purpose for sampling (environmental)
-gradients
-profiles
-zonation
-stratification
Purpose for sampling (stratification)
-site selection will vary depending upon sampling method
-Does site allow for representative sampling?
-What are the environmental conditions?
- safety is a concern
Environmental gradients
-Line transect - anything the line touches
-Belt transect- anything withing the “belt” - give info on density not just abundancesa
sampling method
Quadrant?
Everything?
Quadrant
-frame with which to sample
-Density, Abundance, % coverage
-Considerations:
-How to place?
-Random
-Systematic, eg. transect
-How many
-Consistency
5 measures of biodiversity
-Percentage cover
-percentage frequency
-species richness
species evenness
-SDI- Simpsons diversity index
Percentage cover
-measure of area covered by organism.
-calc by estimating percentage of each quadrat.
-Limitation-qualitative judgment, obscured by vegetation layer/overlap divide quadrat into smaller pieces.
Percentage frequency
percentage quadrat which species appear.
=(mean abundance of species/sum of mean of all speciec) x 100
=(no. of quadrats sampled containing sp./ no. of quadrat sampled) x100
Limitations: ignores density & distribution
Species Richness
tally count of no. of species within a area
(s)=s(no. of different species present)/N^1/2(total no. of individual organisms)
Limitation: ignores abundance.
Species evenness
no. of individual spresent of each sp. in ecosystem in relation to total no. of individuals of all species in area.
show how evenly spread.
shows the domination, or there are significant no.of individuals of many species.
SDI
ration of individuals in each species to the total individuals in ecosystem.
probability 2 individuals randomly selected from samples belong to diff species
Closer the value is to one, higher the biodiversity.
SDI= 1-(Sum of n(n-1)/N(N-1))
n=no. of individuals of each species
N=total no. of individuals at site
Capture Mark Recapture
-Used to estimate size of population of animals where it is impractical to count ever individual
N=M x n/m
M= no. of individuals initially caught, marked & released
n= no. of individuals recaptured
m=no. of recaptured individuals that were marked
