(SL) Unit 5: Evolution and Biodiversity; Topic 5.3 Classification of Biodiversity Flashcards
Flashcard Main Resource: https://ib.bioninja.com.au/standard-level/topic-5-evolution-and-biodi/53-classification-of-biodiv/
Define Species
A group of organisms that can interbreed and produce fertile offspring
What are the 7 characteristics of organisms?
Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, and Nutrition.
What is the binomial system of nomenclature?
It is the formal system by which all living species are classified (taxonomy).
Who developed the binomial system of nomenclature?
Swedish botanist named Carolus Linnaeus
When was the binomial system of nomenclature developed?
in 1735
The binomial system of nomenclature allows for..
the identification and comparison of organisms based on recognised characteristics
The binomial system of nomenclature allows all organisms to…
be named according to a globally recognised scheme
The binomial system of nomenclature can show…
how closely related organisms are, allowing for the prediction of evolutionary links
The binomial system of nomenclature makes it easier to…
collect, sort and group information about organisms
According to the binomial system of nomenclature, every organism is designated a scientific name with two parts, What are they?
Genus and Species
How is the Genus written?
It is written first and is capitalised
How is the species written?
It follows the Genus and is written in lowercase
What is the sub-species?
it is a rank of classification below species
How is the sub-species written?
It follows the species and is written in lowercase
When typing a scientific name, it should be…
typed in italics
When handwriting a scientific name, it should be
underlined
What are domains?
the three major categories of life
All living organisms are classified into three domains, What are they?
Eukarya , Archaea, and Eubacteria
Eukarya are…
eukaryotic organisms that contain a membrane-bound nucleus
What are some examples of Eukarya?
protist, plants, fungi and animals
Archaea are…
prokaryotic cells lacking a nucleus and consist of the extremophiles
What are extremophiles?
a microorganism, especially an archaean, that lives in conditions of extreme temperature, acidity, alkalinity, or chemical concentration.
What are some examples of Archaea?
methanogens and thermophiles
Eubacteria are…
prokaryotic cells lacking a nucleus and consist of the common pathogenic forms
What is pathogenic forms?
organisms that can cause disease
What are some examples of Eubacteria?
E. coli and S. aureus
What are Prokaryotes?
they are single-celled organism which has neither a distinct nucleus with a membrane nor other specialized organelles.
What are Eukaryotes?
they are any cell or organism that possesses a clearly defined nucleus
What is ribosomal RNA?
it is a molecule in cells that forms part of the protein-synthesizing organelle known as a ribosome
Recent evidence from genetic studies of ribosomal RNA has shown that either Prokaryotes or Eukaryotes are far more diverse than anyone had suspected. Which of the 2 is applicable? (Prokaryotes or Eukaryotes)
Prokaryotes
Why was the previously known single kingdom (Monera) reclassified into separate domains?
the discovery of biochemical differences
What is Taxonomy?
it is the science involved with classifying groups of organisms on the basis of shared characteristics
Organisms are grouped according to…
a series of hierarchical taxa, the more taxa organisms share, the more similar they are
The principal taxa for classifying eukaryotes is…
kingdom, phylum, class, order, family, genus and species
What is the kingdom?
a taxonomic group that contains one or more phyla.
What is the phylum?
a subdivision of a kingdom, composed of one or more classes of organism.
What is the class?
a subdivision of a phylum, a class is composed of one or more orders of organism.
What is the order?
a subdivision of a class, composed of one or more families of organism.
What is the family?
a subdivision of an order: composed of one or more genera.
All plant and animal species belong to the same domain (Eukarya) because…
they are composed of eukaryotic cells
Plants and Animals differ in their classification beyond the Eukarya domain as they belong to
different kingdoms
What are the two main classification schemes used to identify living organisms?
artificial classification and natural classification
Artificial classification involves…
arbitrarily selecting unifying characteristics first and then grouping organisms accordingly
What is arbitrarily?
choices on the basis of random choice or personal whim, rather than any reason or system.
What is an advantage of artificial classification?
such schemes are easy to develop and relatively stable (unlikely to change)
What is a disadvantage of artificial classification?
they do not generally show evolutionary relationships
Natural classification involves…
grouping organisms based on similarities first and then identifying shared characteristics
What is an advantage of natural classification?
it can be used to show evolutionary relationships and predict characteristics shared by species within a group
What is a disadvantage of natural classification?
they are highly mutable and tend to change as new information is discovered
What is a disadvantage of natural classification?
they are highly mutable and tend to change as new information is discovered
What is mutable?
liable to change
Which type of classification scheme says that “each taxonomic level includes all species that would have evolved from a common ancestor”
natural classification
The kingdom Plantae contains 12 phyla which includes…
bryophytes, filicinophytes, coniferophytes and angiospermophytes
What does it mean when a plant is vascular?
it means they have phyloen and xylem
What is the role of xylem in a plant?
transports H2O from the roots to other parts of the plant.
What is the role of phyloen in a plant?
transports food/nutrients from the leaves to other parts of the plant.
Which of the kingdom Plantae phyla are non- vascular plants?
Chlorophyta and Bryophyta.
Which of the kingdom Plantae phyla are vascular plants?
Filicpophyta, Conniferophya, Angiospermophyta
What are the structures of Bryophyta
No “true”leaves, roots or stems
Does Bryophyta have vascular tissue?
No
What is the reproduction structure of the Bryophyta?
Spores
What are some features of Bryophytes?
they are anchored by rhizoids
What is an example of a Bryophyta?
Mosses
What are the structures of Filicinophyta?
Have leaves, roots and stems
Does Filicinophyta have vascular tissue?
Yes
What is the reproduction structure of the Bryophyta?
Spores
What are some features of Filicinophyta?
Leaves are pinnate
What is pinnate?
having leaflets arranged on either side of the stem usually in pairs opposite each other.
What is an example of Filicinophyta?
Ferns
What are the structures of Coniferophyta?
Have leaves, roots and stems
Does Coniferophyta have vascular tissue?
Yes
What is the reproduction structure of the Coniferophyta?
Seeds (in cones)
What are some features of Coniferophyta?
Woody stems
What is an example of a Coniferophyta?
Pines
What are the structures of Angiospermophyta?
Have leaves, roots and stems
Does Angiospermophyta have vascular tissue?
Yes
What is the reproduction structure of the Angiospermophyta?
Seeds (in cones)
What are some features of Angiospermophyta?
Have flowers and fruits
What is an example of an Angiospermophyta?
Flowering plants
What are Eukaryotes?
they are any cell or organism that possesses a clearly defined nucleus
What is ribosomal RNA?
it is a molecule in cells that forms part of the protein-synthesizing organelle known as a ribosome
The kingdom Animalia can be sub-divided into two main groups, what are they?
invertebrates and vertebrates
What are invertebrates?
an animal lacking a backbone
What are vertebrates?
organisms which have an internal backbone surrounded by bone, they all belong to the phylum Chordata.
What are the main phyla in the invertebrate phyla?
Porifera, cnidaria, Platyhelmintha, Annelida, Mollusca, Arthropoda, and Chordata.
What kind of symmetry does Porifera have?
None
Is Porifera segmented?
no
Does Porifera have a single entrance body cavity?
No, It has no mouth or anus, instead it has pores to facilitate the circulation of material
What are other features of Porifera?
They are attached to rocks, and have porous along with a filter feeder.
What are examples of Porifera?
sponges.
What kind of symmetry does Cnidaria have?
None
Is Cnidaria segmented?
Yes, it has radial symmetry
Does Cnidaria have a single entrance body cavity?
Yes, it has a mouth but no anus.
What are other features of Cnidaria?
They have stinging cells and tentacles.
What are examples of Cnidaria?
Corals, Jellyfish
What kind of symmetry does Platyhelmintha have?
Bilateral
Is Platyhelmintha segmented?
no
Does Platyhelmintha have a single entrance body cavity?
yes, it has a mouth but no anus
What are other features of Platyhelmintha?
They have a flattened body.
What are examples of Platyhelmintha?
Flatworms
What kind of symmetry does Annelida have?
Bilateral
Is Annelida segmented?
yes, it is very segmented
Does Annelida have a single-entrance body cavity?
No, it has a separate mouth and anus
What are other features of Annelida?
it often has bristles present
What are examples of Annelida?
earthworms and leeches.
What kind of symmetry does Mollusca have?
Bilateral
Is Mollusca segmented?
yes, it has soft or non visible segmentation
Does Mollusca have a single entrance body cavity?
No, it has a separate mouth and anus
What are other features of Mollusca?
Most Mollusca have shells made of CaCO3
What are examples of Mollusca?
Oyster, Snails, Octopus
What kind of symmetry does Arthropoda have?
Bilateral
Is Arthropoda segmented?
yes, it is segmented
Does Arthropoda have a single entrance body cavity?
No, it has a separate mouth and anus
What are other features of Arthropoda?
They have an exoskeleton and jointed appendages.
What are examples of Arthropoda?
Ant, Scorpian, Crab
What kind of symmetry does Chordata have?
Bilteral
Is Chordata segmented?
Yes, it is segmented
Does Chordata have a single entrance body cavity?
No, it has a separate mouth and anus
What are other features of Chordata?
They have a hollow dorsal nerve chord, and a notochord, and (some have) pharyngeal slits.
What are examples of Chordata?
Fish, Birds, Mammals.
Chordates are animals that possess certain key features in an embryonic state that may persist into adulthood, these features include…
a notochord, hollow dorsal neural tube, pharyngeal slits and a post-anal tail
What is an embryonic state?
it is the embryonic stage that lasts through the eighth week following fertilization, after which the embryo is called a fetus.
What are some structural features of organisms in the sub-phylum Vertebrata? (includes birds, mammals, amphibians, reptiles and fish)
the neural tube of the organism will develop into a spine and the notochord will form a protective backbone
What are the main classes in the vertebrate phyla?
Fish, Amphibians, Reptiles, Mammals and Birds.
What kind of limbs do Fish have?
Fins
What kind of gas exchange do Fish have?
Through their gills
How do Fish reproduce?
External Fertilization in most species
What is external fertilization?
when the sperm and egg meet outside the organism.
Do Fish maintain a constant internal body temperature?
No, they are ectothermic
What are other features of Fish?
Their scales grow from their skin, they have a single gill slit, and a swim bladder for buoyancy
What is buoyancy?
Buoyancy is the tendency of an object to float in a fluid.
What kind of limbs do Amphibians have?
4 Pentadactyl limbs
What are Pentadactyl limbs?
A limb with five digits such as a human hand or foot
What kind of gas exchange do Amphibians have?
They have simple lungs with small internal folds and moist surfaces
How do Amphibians reproduce?
They have external fertilization in water and have protective jelly around eggs. Their larval lives in water.
Do Amphibians maintain a constant internal body temperature?
No, they are ectothermic
What are other features of Amphibians?
They have soft moist permeable skin.
What is permeable skin?
permeable skin means that the skin of the organism can let substances go through.
What kind of limbs do Reptiles have?
They have 4 pentadactyl limbs.
What kind of gas exchange do Reptiles have?
they have lungs with extensive folding
How do Reptiles reproduce?
They have internal fertilization and soft shells around the eggs.
What is internal fertilization?
Internal fertilization is the process of fertilization that occurs inside the organism
Do Reptiles maintain a constant internal body temperature?
No, they are ectothermic
What are other features of Reptiles?
They have dry scaly impermeable skin and simple teeth - no living tissue
What is impermeable skin?
it is the skin barrier that does not permit the passage of a fluid
What kind of limbs do Birds have?
They have 4 pentadactyl limbs, 2 limbs modified as wings.
What kind of gas exchange do Birds have?
They have lungs with parabronchial tubes
How do Birds reproduce?
They have internal fertilization and hard shells around the eggs.
Do Birds maintain a constant internal body temperature?
Yes, they are endothermic
What are other features of Birds?
They have feathers growing from their skin and have a beak but no teeth.
What kind of limbs do Mammals have?
they have 4 pentadactyl limbs
What kind of gas exchange do Mammals have?
they have lungs with alveoli
How do Mammals reproduce?
they have internal fertilization, give birth to live young, and have mammary glands which secrete milk.
Do Mammals maintain a constant internal body temperature?
Yes, they are endothermic
What are other features of Mammals?
They have hairs that grow from the skin and have teeth including living tissue.
What is a dichotomous key?
it is a method of identification whereby groups of organisms are divided into two categories repeatedly
How do you know when an organism has been identified?
When the organism no longer shares its totality of selected characteristics with any organism
When using a dichotomous key to identify specimens it is preferable to use…
immutable features (i.e. features that do not change)
