Classification and Taxonomy Flashcards
(21 cards)
What is taxonomy?
Taxonomy is the science of classifying living organisms based on their similarities and differences. It involves grouping organisms into hierarchical categories based on physical and genetic characteristics.
What is the purpose of taxonomy?
Taxonomy helps organize and understand the diversity of life, allowing scientists to identify, name, and group organisms in a logical and consistent way.
What are the 7 taxonomic levels from broadest to most specific
Kingdom, Phylum, Class, Order, Family, Genus, Species
Mnemonic: Kinky Priests Come Over For Great Sex
What are the five kingdoms of life and an example of each?
Animalia – e.g., dog
Plantae – e.g., oak tree
Fungi – e.g., mushrooms
Prokaryotae – e.g., bacteria
Protoctista – e.g., Amoeba
What is binomial nomenclature?
It is the two-part Latin naming system developed by Carolus Linnaeus. It uses the genus (capitalized) and species (lowercase) names. Both are italicized (or underlined if handwritten).
Example: Canis lupus (grey wolf)
Why is binomial nomenclature important?
It provides a universal scientific name for every species, reducing confusion and enabling scientists across the world to communicate clearly
What is a phylogenetic tree?
A phylogenetic tree is a diagram that shows evolutionary relationships between organisms. It illustrates how species are connected through common ancestors and grouped into clades.
What is a clade?
A clade is a group of organisms that includes a single common ancestor and all of its descendants. It reflects evolutionary lineage.
What is cladistics?
Cladistics is a classification method based on genetic data (DNA & RNA) instead of physical characteristics alone. It creates cladograms to show genetic relationships between species.
How do phylogenetic trees help in classification?
They show evolutionary distances and help scientists understand how closely related different species are, based on shared ancestry
What does modern classification rely on, beyond physical appearance?
Modern classification also uses:
Genetics (DNA sequencing, hybridization)
Biochemistry
Immunology
Amino acid comparisons
What is DNA sequencing used for in taxonomy?
DNA sequencing identifies the exact genetic code of an organism. Closely related species will share more similar DNA sequences.
What is DNA hybridisation and how does it work?
It compares DNA strands between two species by measuring the temperature required to separate hybrid DNA strands. The more heat required, the more closely related the species are.
What do biochemical comparisons look at in classification?
They examine internal body chemistry, such as enzymes, hormones, and metabolic pathways, to identify similarities between species
What is the purpose of immunological comparisons?
They involve testing how antibodies from one species react to antigens in another. Greater reactivity indicates closer relation.
What are amino acid comparisons?
This technique compares protein sequences and the amino acid makeup of organisms. Fewer differences mean closer relation.
E.g., Human vs Mouse haemoglobin differs by 27 amino acids.
Why is the armadillo a classification oddity?
Though it resembles reptiles, the armadillo is actually a mammal, with specialized bony plates and epidermal scales
Why are bats unique among mammals?
Bats are the only mammals capable of true flight, using flexible phalanges to support their wings. Despite bird-like features, they are classified as mammals.
What makes whales difficult to classify visually?
Although they resemble fish, whales are mammals. They breathe air, are warm-blooded, and have four-chambered hearts
What is unique about the duck-billed platypus?
The platypus is a monotreme mammal that lays eggs, has webbed feet, and gathers food underwater. Despite bird-like traits, it is still classified as a mammal.
How do pangolins challenge classification?
Pangolins are mammals but share traits with birds and reptiles: they have keratin scales and a keratinised stomach for grinding food, like a bird’s gizzard.
