Unit 3 Topic 1: Classification Process

describe classification for similarity of physical feature (Linnaean system)

The hierarchical classification system categorizes living organisms based on shared characteristics, encompassing various ranks such as domain, kingdom, phylum, class, order, family, genus, and species.

describe classification systems for methods of reproduction

organisms can produce asexually or sexually. And can be r-selected (many offspring, little care) or k-selected (few offspring, high care).

describe classification systems for molecular phylogeny (cladistics)

uses DNA, RNA or protein sequences to classify organisms by evolutionary relationships shown in cladograms.

define clade

group of organisms that includes a single ancestor and all its descendants.

what are 3 common assumptions of cladistics

common ancestry, bifurcation, and physical change

recognise multiple species

biological, morphological, and phylogenetic species

example of an interspecific hybrid that does not produce fertile offspring

mule (equus mulus) which is a cross between a maledonkey and a female horse

define predation and example

one eats another (e.g. lion and zebra)

define competition and example

species fight for the same resources (e.g. plants for sunlight)

define 3 symbiosis and give examples

mutualism: both benefit (e.g. bees and flowers)

commensalism: one benefits, other is unaffected (e.g. barnacles on whales)

parasitism: one benefits, other harmed (ticks on mammals)

define disease and example

pathogens/parasites harm hosts (e.g. frog funal infections)

explain how ecosystems are composed of different habitats

ranging from small microhabitats (under a rock) to large ecoregions (rainforests)

why is classifying ecosystems important for management? (old growth forests, productive soils, and coral reefs)

old-growth forests: knowing they are ancient and biodiverse guides conservation.

productive soils: identifying fertile areas helps in sustainable agriculture and prevents overuse.

coral reefs: recognising them as sensitive marine ecosystems supports protection from pollution and climate change.

what is the purpose of stratified sampling

estimates population, density, distribution and study environmental gradients or zonation

what is site selection

divide area into different strata and sample each one.

define r-selection

produces many offspring with little parental care and they often thrive in unstable/changing environments.

define k-selection

produces few offspring with high parental care and thrive in stable environments near carrying capacity.

define biological species

a group of organisms that can interbreed and produce fertile offspring

define morphological species

a group of organisms defined by their physical features.

define phylogenetic species

a group of ancestors that share a common ancestor and form the smallest branch of an evolutionary tree.

define bifurication

a split into two branches on an evolutionary tree, showing where one species diverged into two.