4.3 Flashcards
Taxonomic hierarchy of biological classification of species:
Domain Kingdom Phylum Class Order Family Genus Species
Binomial system of naming species + advantage of using this
It's Latin First name (genus) has capital letter second name doesn't + italics/underlined e.g Homo sapiens (underlined/ italics)
Advantages: helps to avoid the confusion of using common names
5 different kingdoms
Prokaryotae Protoctista Fungi Plantae Animalia
Characteristics of Prokaryotae
•prokaryotic
•single celled, no nucleus
E.g bacteria
Characteristics of Protoctista
•Eukaryotic
•Usually live in water
•single celled/simple multicellular organisms
E.g algae
Characteristics of fungi
•eukaryotic
•single/multicellular organisms
•absorb substances from dead/decaying organisms (saprotrophic)
E.g moulds
Characteristics of plantae
•eukaryotic •multicellular •cellulose cell walls •photosynthesise (autotrophic) •chlorophyll E.g flowering plants
Characteristics of animalia
•eukaryotic •multicellular •no cell walls •consume plants + animal (heterotrophic) E.g mammals
Phylogeny
The study of the evolutionary relationships between organisms
In the original classification system what did they use to classify animals?
Observable features
What is the new classification system
The three domains of life:
Eukarya
Archaea
Bacteria
What evidence has led to new classification systems
Molecular evidence - some enzymes/proteins are different in similar molecules
What evidence is used now to decide how to classify organisms
- Similarities in biological molecules
* Genetic evidence
Relationship between classification and phylogeny
Classification systems take into account phylogeny when arranging organisms into groups.
Evidence for the theory of evolution by natural selection
Darwin Wallace Fossils can show gradual changes DNA looking at DNA base sequences comparing sequences of amino acids in proteins
Intraspecific variation
The variation between members of the same species
Interspecific variation
The differences between species
Differences between continuous + discontinuous variation
Continuous - individuals vary within a range, no distinct categories
Discontinuous - 2 or more distinct categories
Examples of continuous variation in animals, plants and microorganisms
Animals: milk yield, mass
Plants: no. of leaves, mass
Microorganism: width length
Examples of discontinuous variation in animals, plants and microorganisms
Animals: blood type
Plants: colour, seed shape
Microorganisms: antibiotic resistance, pigment production
Ways to compare data when looking at variation
- Standard deviation
- T-Test
- Spearman’s rank correlation coefficient
Genetic causes of variation
Different versions of the same gene (alleles)
Environmental causes of variation
Differences in environment
Genetic & environmental causes of variation
Genetic factors determine characteristic ur born with but environmental factors can influences how some characteristics develop
Behavioural adaptations
Ways an organism acts that increase its chance of survival e.g playing dead
Physiological adaptations
Processes inside an organism’s body that increase its chance of survival e.g hibernation
Anatomical adaptations
Structural features of an organism’s body that increase its chance of survival e.g whales have a thick layer of blubber
Why do organism’s from different taxonomic groups sometimes show similar anatomical features + example
The organisms have evolved in similar environments and to fill similar ecological niches (role of organisms within its habitat e.g what when where it eats)
E.g marsupial and placental mammals
Describe the Marsupial and Placental Mammals
Marsupials e.g kangaroos
•shorter gestation period (pregnancy)
•don’t develop full placenta
•born early then climb into mothers pouch, attach to test and receive milk, continue to develop
Placental e.g humans
•longer gestation period
•develop placenta
•fully developed
Marsupial + Placental moles
Share similar anatomical features as they've both evolved to live in similar environments E.g Both live in tunnels Small/nonexistent eyes No ears Claws 4 dig Tube body cone head Scoopy paws 4 dig
