Classification and evolution Flashcards
Taxonomic (linnaean) classification
(do keep pond clean or frog gets sick)
Domain, kingdom, phylum, class, order, family, genus, species
Phlyum- similar characteristics
Class- mammals, birds, reptiles…
Why binomial nomenclature (using genus and species) used instead of common names
- More than 1 common name
- Shows genus
- Binomial nomenclature is consistent- can be used by scientists everywhere
Why is classification used?
- to identify evolutionary links
- to predict certain characteristics
- to identify species
Differences between artificial classification and natural classification
Artificial (based on observable characteristics)
- uses only physical characteristics
- does not show evolutionary relationships
- does not change
Natural (based on evolutionary relationships)
- uses many characteristics such as physiology, biochemistry
- Shows evolutionary links
- changes as knowlege advances
5 kingdoms
3 domains
differences between 3 domains
Who made the 3 domain system
- Animalia, Plantae, Fungi, Protoctista, Prokaryotae
- Animalia, Plantae, Fungi, Protoctista, eubacteria, archaebacteria
- eukarya, archae, bacteria
Bacteria
- peptidoglycan cell wall
- 5 proteins in RNA polymerase
- 70S ribosomes
Archae
- no peptidoglycan cell walls
- 8-10 proteins
- 70S ribosomes
Eukarya
- No peptidoglycan cell walls
- 12 proteins
- 80S ribosomes
Observable feature of different kingdoms:
- Animalia
- Plantae
- Fungi
- Protoctista
- Prokaryotae
Animalia
- Multicellular
- Membrane bounds organelles
- Heterotrophic
- Mechanisms of motion: cilia, flagella, contractile muscles
Fungi
- unicellular or multipcellular
- saprophytic
- membrane bound organelles
- no mechanism of motion
- chitin cell wall
- threads of hyphae in body
Plantae
- multicellular
- membrane bound organelles
- autotrophic
- no mechanism of motion
- chloroplasts
- cellulose cell wall
- store food as starch
Prokaryote
- unicellular
- no membrane bound organelles
- flagella (flagellin)
- no mechanism of motion
- saprophytic
Protoctista
- unicellular
- membrane bound organelles
- heterotrophic or saprophytic
- chloroplasts
What is phylogeny
Benefits of phylogony compared to classification
What is is called when organisms of different species come from same species (other than divergent evolution)
Phylogeny is the evolutionary relationships between organisms and how closely related they are.
Phylogeny uses a continuous tree, classification uses discrete taxanomical groups.
taxanomic classification hints thta all organisms in a rank are equal.
Monophyletic species
Variation affected by:
Environmental or genetic factors
Causes of genetic variation
Environmental causes of variation
- mutation- change in DNA sequence causes chage in protein which affects physical and metabolic characteristics
- Meiosis- independent assortment, crossing over
- Random fertilisation- random sperm fertilises egg so random combination of genetic material
- Sexual reproduction- offspring inherits genes from mother and father, creates different allles
Climate, diet, lifestyle
What is:
continuous variation
Discontinuous variation
Continuous variation- characteristic that can take any value within a range
DIscontinuous variation- Characteristic that can only result in certain set values.
More about continuous and discontinuous variation
Continuous
- caused by many genes (polygenic)
- caused by genetic and environmental factors
- Bell curve, scatter graph, histogram
Discontinuous
- caused by single gene
- Caused by just genetic factors
- Pie chart, bar chart
What are adaptations
Types
Characteristics that increase an organisms chance of survival
Behavioural
Anatomical
Physiological (biochemical)
Marram grass adaptations:
Behavioral
Anatomical
Physiological
Behavioral:
- Stomata close and leaf rolls tighter in water shortage
- Plant grows when covered in sand
Anatomical:
- Waxy cuticle
- Curled leaves
- Hair leaves
-folded to create pits for stomata
Physiological
- Lignified cells
- Guard cells
Moles showing convergent evolution
Placental and Marcupial mole
- streamlined
- Velvety fur
- No eyes
- Modified forelimbs
Selectional pressure process
Examples of selectional pressure
Factors that affect an organisms chance of survival and ability to reproduce.
-Organisms in a species show variation due to alleles.
- Organisms with advantageous allele are better adapted to selectional pressure and more likely to survive and reproduce. (‘survival of the fittest’)
- The advantageous allele is passed down to offspring and process is repeated, until greater proportion of individual with adv. allel.
- Frequency of adv. allele increases in species gene pool
competition, disease, predation