Classification Flashcards
What is the level of hierarchy?
Domain Kingdom Phylum Class Order Family Genus Species
acronym for hierarchy
King phillip comes over for great spaghetti
What is the domain?
highest taxonomic rank
What is the phylum, what does it contain?
- major subdivision of the kingdom
- groups of organisms that have the same body plan (ie presence of backbone)
What is a class?
group of organisms that possess the same general traits (ie same number of legs)
What is an order?
subdivision of the class w additional info (ie mammals divided into herbivores/ carnivores)
What is a family?
a group of closely related genera (ie within carnivores we have the cat family and the dog family)
What is a genus?
group of closely related species
What is a species?
the basic unit of classification
What are the 3 domains?
Archaea, Eubacteria, Eukarya
What are the five kingdoms?
Prokaryotes Protoctista Fungi Plantae Animalia
What are some features of prokaryotes? (nucleus, DNA, organelles, cell wall, ribosomes, free living/ parasitic)
- no nucleus
- loops of DNA
- no membrane bound organelles
- Cell wall made up of peptidoglycan
- small ribosomes
- free living and parasitic
What is the role of mesosomes in prokaryotes?
carry out respiration
How do prokaryotes reproduce?
binary fission, some reproduce sexually
What are the 3 common shapes of prokaryotes?
helix, sphere, rod
Examples of prokaryotes
bacteria
What are some features of protoctista? (eukar/ prokar, single/ multicellular, organelles, nutrition, free living/ parasitic)
- eukaryotic
- single celled
- have characteristics of both plant and animals (contain chloroplasts)
- autotrophic and heterotrophic
- free living
Where are proctoctista commonly found and what are some examples of them?
in water algae seaweeds ameoba plasmodium
What type of nutrition do protoctista have?
autotrophic and heterotrophic
What is autotrophic and heterotrophic nutrition?
autotrophic - nutrition through photosynthesis
heterotrophic - nutrition through digesting and absorbing food
How are protoctista mobile?
flagella
cilila
pseudopods (false feet)
What are some features of fungi? (ukar/ prokar, single/ multicellular, extra feature, cell wall, cytoplasm, digestion, reproduction, type of nutrition, free living/ parasitic)
- Eukaryotes
- single and multicellular
- have mycelium that consists of hyphae
- cell wall made of chitin
- cytoplasm multinucleate in filamentous fungi
- extracellular digestion - excreting enzymes and absorbing soluble products
- reproduction by releasing spores
- saprophytic nutrition
- free living
What is saprophytic nutrition?
feeding on decaying matter
example of fungi
fungi on an orange
What are some features of Plantae? (eukary/prokar, single/ multicellular, cell wall, organelles, type of nutrition, free living/ parasitic)
- Eukaryotic
- multicellular
- cell wall cellulose
- contain chloroplasts, vacuoles
- autotrophic (food through photosynthesis)
- free living
What are the two types of plants (simple, complex)?
non-vascular and vacular
What are non vascular plants called and what features do they have? How do they reproduce?
- bryophytes
- lack root, stems, leaves
- reproduce through spores
How do vascular plants reproduce?
produce seeds
What are the features of animalia? (eukar/ prokar, single/ multicellular, type of nutrition, mobility)
- eukaryotic
- multicellular
- heterotrophic
- can move around
What is the need for classification?
- identify species
- predict characteristics
- find evolutionary links
What is the advantage of using binomial nomenclature?
it helps avoid confusion of using common names
What is the advantage of using binomial nomenclature?
it helps avoid confusion of using common names
How do you write names using the binomial nomenclature?
Genus - first name (start with capital letter)
species - surname (start with small letter)
full name underlined
What is phylogeny?
evolutionary relationships between organisms
How is phylogeny related to classification?
the closer the evolutionary relationship, the closer the taxonomic grouping
How are phylogenetic trees drawn out?
- starts with the common ancestor, branches out to more common ancestors
- starts from past species, branches out to new
- continuous
- the closer two species are on the phylogenetic tree, the closer related they are
What are the advantages of phylogeny compared to classification?
- phylogeny produces a continuous tree
- classification requires discrete taxonomical groups
What are the five evidences used in classification?
anatomical embryological behavioural biochemical immunological
What is anatomical evidence?
organisms with more homologous structures are closer in the phylogenetic tree
What are homologous structures
structures that appear to be different but have same underlying function ( ie bird wings and human arms )
What is embryological evidence?
- the more similar the embryos look, the closer they are phylogenetically
- evidence that organisms evolved from a common ancestor
What is an example of behavioural evidence?
ie humans - longer period of parental care, live in social groups, vocalisation and facial expression
What is convergent evolution?
where unrelated organisms develop similar structures, performing the same job (analogous structures)
What is biochemical evidence?
- comparing the number of amino acids in Cytochrome C
- DNA Hybridisation
What is cytochrome C and why is it used for biochemical evidence for classification?
a protein that is found in the mitochondria (found in any respiring organism)
What is DNA hybridisation?
- extraction and comparison of DNA samples of two species
- sequences of proteins in DNA strands are compared
What is immunological evidence?
- inject human serum (blood plasma without clotting proteins) into rabbit
- serum contains proteins which can act as antigen if they enter blood of a diff species
- antigens make rabbit produce antibodies
- rabbit serum removed and added to test tube
- reaction will produce precipitate
- the higher the precipitate, the closer the evolutionary relationship
What are the three evidences for evolution?
1) Palaeontology
2) Comparative anatomy
3) Comparative biochemistry
What is palaeontology?
study of fossils and the fossil record
What is evidence provided by the fossil record?
(1) fossils of simpler organism found in older rocks, fossils of more complex structures found in recent rocks
(2) plant fossils appear before animal fossils, matching idea that animals require plants to survive
(3) find out how closely related organisms are based on similarities/ differences between fossils
(4) find out if current living organisms are related to certain extinct organisms
What is a disadvantage of palaeontology?
- many organisms are soft bodied + decompose before they fossilise
- conditions needed to fossilise rarely present
- other fossils have been destroyed
What is evidence provided by comparative anatomy?
- studying similarities and differences between the anatomy of living species
- homologous structures, evidence of divergent evolution
What evidence is provided by comparative biochemistry?
- study of similarities and differences in DNA sequence and protein sequence (cytochrome c)
- similarities/ differences between:
• nucleotide
•base sequence - the more similar the sequences, the closer related the species are
What are variations?
the differences in characteristics between organisms
What are the two types of variation?
interspecific and intraspecific
What is the difference between inter and intra specific variation?
interspecific - variation between different species
intraspecific - variation between the same species
What are the causes of variation?
genetic
enviromental
What are the 5 genetic causes of variation?
alleles mutations meiosis sexual reproduction chance
How is genetic variation caused by alleles?
individuals in a species population may inherit a different allele of a gene
How is genetic variation caused by mutations?
- mutations cause changes in the DNA sequence and therefore the gene
- causes changes in proteins
- can affect changes in physical and metabolic characteristics
How is genetic variation caused by meiosis?
through independent assortment and crossing over
How is genetic variation caused by sexual reproduction?
offspring inherits genes (alleles) from each parent
How is genetic variation caused by chance?
it is a result of chance as to which two gametes from each parents fuse
How can genetic variation take place in asexual reproduction?
through mutations
What is a characteristic that is classed as purely environmental?
scarring (due to accidents/ surgeries)
What is the difference between continuous and discontinuous/ discrete variation?
continuous - a characteristic that can take any value over a range
discontinuous/ discrete - a characteristic that can only hold certain values
What is the difference between continuous and discontinuous/ discrete variation in terms of the amount of genes they are controlled by?
continuous - controlled by more than one gene (multiple genes - polygenes)
discontinuous - controlled by a single gene (ABO gene)
What are some examples of continuous and discontinuous variation?
continuous :
• height
• mass
discontinuous:
• shape of organism (ie shape of bacteria)
• sex of animal
How can continuous/ discontinuous data be presented?
continuous - histograms
discontinuous - bar chart, pie chart
How can continuous data be distributed?
on a normal distribution curve
What are the characteristics of a normal distribution?
- mean, mode and median are the same
- the curve has a bell shape (symmetrical)
- half of the values are less than the mean and half if the values are greater than the mean
- most values lie close to the mean value
What is an adaptation?
characteristic that increase the chance of an organisms survival and reproduction in its environment
What are the three different types of adaptations?
anatomical
behavioural
physiological
What are 4 examples of anatomical adaptations?
- body covering
- camouflage
- teeth shape
- mimicry (copying another animals appearance)
What are the two types of behavioural adaptations?
innate - inherited through genes
learned behaviour - learned from experience/ other animals
What are three examples of behavioural
adaptations?
- survival behaviours - playing dead
- courtship - ie dancing to attract other animals to reproduce
- seasonal behaviour - migration and hibernation
What are three types of physiological adaptations?
- poison production
- antibiotic production
- water holding
How can animals from different taxonomic groups show similar anatomical features (ie marsupial mole and placental mole)?
Through convergent evolution:
• unrelated species show share similar traits
• live in a similar way to each other
What are selection pressures?
factors that affect organisms chance if survival/ reproduction success (fertile offspring)
How does natural selection result in evolution?
- random mutations –> new alleles
- some alleles –> provide advantage against selection pressures (organism more likely to survive and reproduce)
- offspring receive the new allele and therefore have ‘evolved’
How did Darwin and Wallace contribute to the theory of evolution?
observed that birds had diff beak shapes
- birds with beaks most suited to the food they eat are more likely to survive and therefore pass their beak shape to offspring
What are some implications for humans due to evolution?
- bacterial antibiotic resistance means infections are harder to treat
- pesticide resistance means entire crops could be destroyed
How is the 3 domain system different to the five kingdoms
domain:
- compares differences in DNA
- splits prokaryotes into archaea and eubacteria
- groups eukraya together (fungi, protoctist, plantae, Animalia) therefore there are many similarities between all eukaryotes
