IB Biology Natural Selection and Classification of Biodiversity

Variation

Slight differences made through random mutations within a population that allow an organism to be better adapted to their environment

Genetic variation in meiosis

During prophase I the crossover of chromosomes creates new combinations in alleles which can code for new characteristics; and random assortment of chromosomes from both parents create many combinations for the offspring’s genetics

Natural selection

A characteristic within an individual of a species that is advantageous allows it to survive and pass on its genetics (and therefore advantageous characteristics) until the entire population has this trait

Process of natural selection

Population produces more offspring than the environment can support; this creates competition for territory, food, mating opportunities, more chances for spreading diseases; sexual reproduction greates genetically varied offspring so those with disadvantegous traits die and advantageous traits pass on their genes; population receives increased allele frequency of that trait so more adapted to the environment

Adaptive radiation

The process of a species becoming separated and diverging due to environmental factors to become two different species

Species

A group of organisms that can interbreed to produce fertile offspring

Binomial nomenclature

A naming system that classifies organisms by genus-species, originating from Carl Linnaeus

Classification system order (least specific to most)

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Classification system order acronym

Don’t Know, People Can Order From Grab Sometimes

Domain

The largest class function, there are three domains: archaea, bacteria, eukaryota

Archaea

Extremophile organisms that do not have a nuclear membrane and have distinct RNA and biochemistry

Bacteria

Organisms that have no nuclear membrane and can cause disease within humans

Eukaryota

Organisms with nuclear membranes

Animal classification example (human)

Eukaryota Animalia Chordata Mammalia Primates Hominidia Homo Sapiens

Plant classification example (meadow buttercup)

Eukaryota Plantae Spermtophyta Eudicotyledons Magnoliidae Ranunculales Ranunculus Acris

Vascular plants

Vascular (tracheophytes) plants contain water transportation systems (xylem and phloem)

Non-vascular plants

Include bryophytes and chlorophyta, they do not have vascular systems for water transportation (xylem and phloem)