4.2.2 Flashcards
What are taxonomic groups?
Kingdom Phylum Class Order Family Genus Species
What is another word for hierarchical classification systems?
Linnaean classification
Why is classification used?
- Identify species
- predict characteristics
- find evolutionary links
How organisms are classified?
They are first split into three domains:
- archaea
- bacteria
- eukarya
What is the binomial nomenclature?
First word: organism genus
Second word: organism species
What are the five kingdoms?
Procaryotae Protoctista Fungi Plantae Animalia
Describe prokaryotae
Unicellular
No membrane-bound organelles
No visible feeding mechanism
Describe protoctista
Unicellular
Has a nucleus and other membrane-bound organelles
Some of sessile, some move
Nutrients are required in one of two ways:
-Photosynthesis (autotrophic feeders)
-Ingestion of other organisms (heterotrophic feeders)
Or both
Some are parasitic
Describe fungi
Unicellular/multi cellular
Chicken cell wall
New mechanisms for locomotion
Body made of mycelium made of threads/hyphae
Nutrients acquired by absorption (saprophytic feeders)
Describe plantae
Multi cellular
Sam can move using cilia/flagella
Nutrients acquired by photosynthesis (autotrophic feeders)
Describe Animalia
Multicellular
Move with cilia/flagella/contractile proteins/muscular organs
Nutrients acquired by indigestion (heterotrophic feeders)
What’s the difference between the ribosomes in E, A, B? And how many proteins do each of these RNA polymerise have?
Eukarya: 80s, 12 proteins
Archaea: 70s, 8-10 proteins
Bacteria: 70s, 5 proteins
What is phylogeny?
Evolutionary relationships between organisms
What is phylogenetics?
Study of evolutionary history,
Reveals which group a particular organism is related to and how closely
What do you phylogenetic trees show?
evolutionary tree is used to represent evolutionary relationships between organisms
What are the three advantages of phylogenetic trees?
- doesn’t need reference to linnaean classification
- Continuous tree, unlike discrete taxonomical groups (scientists not forced to put organisms in groups they don’t fit)
- Hierarchical nature of Linnean classification can be misleading as it implies different groups in same rank are equivalent
What is palaeontology?
Study of fossils and fossil record
What is comparative anatomy?
Similarities and differences between organisms anatomy
What is comparative biochemistry?
Similarities and differences between chemical make-up of organisms
Why is it possible to know the fossil record?
Fossils preserved in rocks
Sediment is deposited (forming layers – strata – of rocks)
Different layers correspond to different geological eras
What does the evidence from palaeontology tell you?
- Simple life involves (bacteria and simple algae in oldest rocks but more complex vertebrates in recent rocks)
- Sequence in which they are found match ecological links to each other
- can investigate extinct and living organisms
Why are some fossil record is not complete?
- Some of softbodied (decompose before they can fossilise)
- some destroyed in earth movements
- some are undiscovered
What is a homologous structures?
They appear to be superficially different but they have the same underlying structure
Provides evidence of divergent evolution (happens when closely related species diversify to adapt)
How is comparative biochemistry done?
Proteins and other molecules that control life processes are studied
E.g. cytochrome and ribosomal RNA
What is interspecific variation?
Between members of different species
What is intraspecific variation?
Between organisms within a species
What are the two main causes of variation?
Genetics and environment
What are the five genetic causes of variation?
- Values
- mutations
- meiosis (IA., CO)
- sexual reproduction
- chance
How does genetic variation happen in a sexual reproduction? Why?
Only due to mutation
Because asexual reproduction results in clones
Which species is more affected by environmental variation and why?
Plants
Lack of ability
What is discontinuous variation?
Characteristic that can only result in certain values
Pie/bar charts
What is continuous variation?
Characteristic that can take any value within a range
Histogram
What is standard deviation a measure of?
How spread out the data is
The greater the standard deviation, the greater the spread
What does the t-test do?
Compares the means of data values of two populations
What does Spearman’s Rank do?
Considers the relationship between two sets of data
What did the results of the Spearman’s Rank tell you?
+1:Perfect positive correlation
- 1: perfect negative correlation
0: no correlation
What are adaptations?
Characteristics that increase in organisms chance of survival and reproduction
What are three types of adaptations?
- Anatomical (physical features)
- behavioural (inherited all learnt)
- physiological (processes that take place inside an organism)
Give four types of anatomical adaptations
- Body covering
- camouflage
- teeth
- mimicry (copying another animals appearance)
How is marram grass adapted to live in an environment with a little water?
- Cold leaves
- hairs on leaves
- stigmata sunk into pits
- thick waxy cuticle
What are three types of behavioural adaptations?
- Survival (playing dead)
- courtship (dancing)
- seasonal (migration/hibernation)
What are the two categories of behavioural adaptations?
- Innate: inherited through genes
- learned: from experience or observation
What are physiological adaptations give 3 examples?
- Poison
- antibiotic production
- water holding (survival in deserts)
What are analogous structures?
Adapted to perform the same function but have a different genetic origin
When does convergent evolution take place?
When on related species begin to share similar traits due to similar environments or other selection pressures
Give an example of convergent evolution
Marsupials (Australia)
Placental mammals (America)
Both have embryos that connects to the mothers circulatory system by placenta but marsupials start life in the uterus and leave it inside the marsupium while still embryos
Give three other examples of convergent evolution
- Marsupial and placental mice
- flying phalangers and flying squirrels
- marsupial and placental moles
