Topic 4 Flashcards
What is a species
Group of organisms that can interbreed to produce fertile organisms.
Population
Group of interbreeding organisms of same species found in an area (community is various population in a habitat)
Niche
The way an organism exploits it environment
Endemic
Only place organism is found
Adaptations (with examples)
Adaptations-features that enable organism to survive
—>Behavioural- changes in behaviour (mating calls)
—>Physiological-changes of internal processes in organisms (regulation of blood flow)
—>Anatomical-internal or external structure/physical changes (giraffe long neck)
Co-adaption process
When a two or more species undergo adaptions in a group
Natural selection
Process in which fitter individuals survive and pass on beneficial Allele to future generations
Evolution
Process when frequency of alleles in a gene pool (all alleles of all genes in a population) changes over time due to natural selection
Evolution via natural selection steps
1)Variety of phenotypes exist in population due to mutation
2)environmental changes occur so selection pressure changes
3)individuals with beneficial allele survive and reproduce
4)so frequency of alleles changes over time(evolution)
Heindy Weinberg equation
Conditions for equation - no mutation,Random mating,reproductive rate,large population size,gene pool size.
Reproductive isolation
If 2 populations become reproductively isolated new species formed due to accumulation of different genetic information in populations over time due to different selection pressures
Speciation (allopatric/sympatric)
Speciation-formation of species
Allopatric-in groups geographically isolated
Sympatric-isolated by other means (i.e in same area)
Biodiversity
Variety of living organisms in particular wealth of different species that exist due to evolution via natural selection
Taxonomy
Placing organism into groups based on shared features
Hierarchy of taxonomy
Kingdom
Phyla
Class
Order
Family
Genus
Species
What are the 5 kingdoms
Animalia (eukaryotes that are heterotrophs)
Plamtae (eukaryotes that are autotrophs)
Fungi (eukaryotes that are heterotrophs absorbing decaying matter)
Protoctista (eukaryotes that photosynthesise)
Procaryotae (prokaryotes, like bacteria)
How does scientific community evaluate data
Peer review
Present work at scientific conferences
Publish work
Genetic diversity
Measure of genetic variation found in species (number of Alleles in a gene pool), the higher variety of genotypes the more diverse the population.
Genetic variation could result from: meosis or random DNA mutations
Species richness
Number of species in habitat (most common Is called dominant)
Ways of measuring biodiversity
Ways of measuring genetic diversity (indirect/direct)
Direct method- DNA sequencing to determine bases that determine which alleles are present
Indirect method-DNA cut into fragments and separated by gel electrophoresis, different alleles identified as they produce different fragments
How do plant build tall structures
-produce strong cell walls out of cellulose
-build tall columns/tubes from specialised cells
-stiffen special cell with lignin
Structure of plant
Chloroplast- site of photosynthesis
Vacuole- contain cell sap and help store mineral also used for strength , surrounded by tonoplast (single membrane). Vacuole is turgid when H2O added.
Cell wall- made of cellulose, made of middle lamella holding cells together and cellulose microfibrills/microfibres
Amyloplasts- store amylopectin (starch), surrounded by double membrane
Pits- thin sections allowing communication between adjacent cells
Plasmodesmata- extension of cytoplasm between cell wall of adjacent cells involved in transport
Cellulose
Chain of Beta glucose. Condensation reaction. 1,4 glycosidic bonds. Straight chain. H+ bonds between neighbouring OH groups and cellulose bundles form microfibrils, glue holding microfibrils together is composed of hemicellulose and pectins. Microfibrils provide strength/support they lay down at different angles.