OCR Biology - F212 - Module 3 (In progress)

1. Adaptations

   Nota:

   • Features that enhances survival and long-term reproductive success.
   • An adapted organism will be able to: Find food better or photosynthesis well. Find enough water. Gather enough nutrients. Defend itself from predators or diseases. Survive the physical conditions of its environment, such as change in temperature. Respond to changes in its environment. Still have enough energy to successively.
   1. Behaviour

      Nota:

      • The organisms behaviour is affected by seasons, contact or mating rituals.
   2. Physiological / Biochemical
   3. Anatomical

      Nota:

      • Structural enhances to an organism
2. Variation

   Nota:

   • The presence of variety of differences between individuals or within a population Genetic variation= caused by differences in genes, combination of genes and alleles
   • Variation in a species can be due to size, gender, mutations, or diet.
   1. Continuous
      1. Effect of many genes
      2. Quantitative
      3. No distinct groups
      4. A range of intermediate values with two extremes on either end of the scale
      5. e.g. weight, height
   2. Discontinuous
      1. Effect of one or few genes
      2. Little/ no environmental effect
      3. Discrete categories, no intermediates
      4. E.g. sex
   3. Causes
      1. Genetic

         Nota:

         • different alleles or combination of alleles e.g. gene on hair colour
      2. Environmental

         Nota:

         • E.g. sun exposure and skin colour. Wind direction and direction branches grow
3. Evolution seen today

   Nota:

   • Resistance to drugs. This is a problem to humans as: Diseases become untreatable. Potential disease outbreak. Developing new drugs is expensive and takes time.
4. Speciation
   1. Natural selection

      Nota:

      • The process that an organism will randomly mutate and if that mutation means it can survive better, that trait will be passed on to its offspring and in time a new species will arise (Speciation) 
      1. Finches (Case study)
      2. Evidence for

         Nota:

         • Fossils: Show organisms have changed over time. Fossils and rocks can be dated. A series of fossils can show a trend from simple to more complex, intermediate forms.
         • Anatomy, physiology, behavior.
         • Embryology.
      3. Reproductive barriers
      4. Process of natural selection
         1. A mutation occurs which is random
            1. Selection pressure based on how the mutation helps
               1. Individuals with mutation survive
                  1. The mutation is passed on to next generation
                     1. Over many generations that characteristic is shown in more individuals
   2. Isolation/separation

      Nota:

      • E.g. river or mountain stops interbreeding 
      1. Allopatric

         Nota:

         • Different locations
      2. Sympatric

         Nota:

         • When either a courtship dance is no longer recognised, or sexual organs are no longer compatible and they cannot mate. 
   3. Mutations
   4. Different selection pressures
   5. Enough time to allow changes to prevent interbreeding

Nota:

• Organisms are organised: for our convenience to make the study of natural things more manageable to make identifying organisms easier to help us see the relationships between species
• It is important that organisms are identified as they are important to their habitat. Meaning scientists need to know what is in the area they are working in and know what to look for so that species is protected
• Some closely related organisms can share there scientific name as they have the same genus and have similar characteristics, even share a common ancestor.

1. Kingdom
   1. Animalia

      Nota:

      • No cell walls. Heterotrophic. Eukaryotic. Multicellular. Fertilized eggs develop into a ball of cells. High degree of mobility. 
   2. Fungi
   3. Plantae
   4. Protoctists
   5. Prokaryotes

      Nota:

      • No nucleus No membrane bound organelles Non-linear chromosomes DNA not associated with histones Small cells Cell wall, peptidoglycan
2. Phylum
3. Class
4. Order
5. Family
6. Genus
7. Species

   Nota:

   • A species is a group of individual organisms with similar appearance, anatomy, behaviour, biochemistry and genetics. When they reproduce, they produce fertile offspring.
8. Old methods
   1. Binomial

      Nota:

      • Using 2 names to to identify a species, the genus and species.
      • Needs to be written in italics, or underlined and no capital letter on the species name
   2. Dichotomous key

      Nota:

      • A series of 2 possible answer question questions to identify a species 
9. New methods
   1. DNA

      Nota:

      • Every organism has DNA or RNA. It is the most accurate way to determine how related 2 species are, as if a sequence of DNA codes a protein, it will be the same sequence in a bacteria, an animal etc.  Like amino acids, The same 3 conclusions can be made.
      • This has been backed up by evolutionary relationships we already know, and can be used to clarify relationships we are unsure about.
   2. Amino acids

      Nota:

      • The sequence of amino acids draw 3 conclusions: If the sequence is similar, the 2 species are closely related. If the sequence is very different, the 2 species aren't closely related. The more similarities in the sequence, the closer they 2 species are related.
   3. 3 domains
      2. Based on differences in DNA, RNA
      3. IT more accurately reflects origins of prokaryotes/eukaryotes
      4. Divides prokaryotes into two and reflects differences in eubacteria and archaeabacteria
      5. Domain groups eukaryotes together as it reflects the simularities in eukaryotic kingdoms e.g. membrane bound organelles
   4. RNA
   5. Cytochrome C
10. Genetic relationships

    Nota:

    • Based on: family, Genus, common ancestor common genes (give similarities) Differences (Give examples)

1. Conservation

   Nota:

   • Problems can occur when reintroducing an organism to a habitat: Compete with current life, local habitat may not be suitable, they may not adapt to local conditions, might bring disease
   1. In situ

      Nota:

      • In the organisms natural habitat
      1. Put laws in place to ban human impacts on the species e.g. hunting/fishing
      2. Quotas.limiting number of animals that can be caught
      3. Protect habitat from e.g. drilling
      4. Promote other species for the endangered species to eat
      5. Educate people in the relevant industry
   2. Ex situ

      Nota:

      • Not in its natural habitat/ climate
      1. Seed banks

         Nota:

         • Advantages: Dont take up alot of space Can store a lage number of speciesIf temperature is -5*C, life span is x2.If humidity is -1%, lifespan of seed is  x2.Can be stored in excess from wild.Easy to transport.Seeds can be collected without damaging plants Less susceptible to pests/disease
         • The seeds need to be genetically different so: There is a larger gene pool. Reduced chance of future disease wiping out whole population. Reduce chance of interbreeding. Maintain geographical variation.
      2. Zoos/captive breeding
   3. Why?

      Nota:

      • Conservation is important because: Organisms are part of an ecosystem for other organisms. They are part of a food chain. Potential source of medicine and genetic resource. Non-medical research. Aesthetic value. Ethical reasons.
2. When we dont protect
   1. Extinction

      Nota:

      • More animals become endangered or extinct due to climate change, loss of habitat and an increase of human population, disease, change in food supply/predators, environmental change to rapid for adaptation
   2. Biodiversity loss
      1. Importance of genetic diversity
   3. Affects of climate change
3. Conventions
   1. CITES

      Nota:

      • Regulate trade of selected species,  Ensure trade does not endanger species, prohibit trade of wild plants, allow trade of artificially propagated plants, allow some trade of less endangered organisms
   2. EIA

      Nota:

      • Things to be considered when carrying out an environment impact survey,  Biodiversity of area, any endangered species, rarity of the habitat, movement of organisms when the habitat is lost, effect on reduced size of ecosystem, a method to minimize the impact.
   3. Rio convention

      Nota:

      • Policies include: Sustainable use of ecosystems, Shared genetic resources, Share access to knowledge, International cooperation, Raising profile of biodiversity to government.

Nota:

• The variety of organisms found, the variety of habitats found, the number of different species found, the genetic diversity within species

1. Sampling

   Nota:

   • The number of counted animals/species will be different to the actual number of animals/species because: Not all areas discovered/explored.  Some organisms can be difficult to see (Small, nocturnal) They might be rare. Some species difficult to define.
   • When conducting a field investigation for change to a species: Sampling needs to be done before and after the change. Random sampling needs to be achieved so it is unbiased. Use an appropriate sampling technique. Perform the investigation at different times/weathers. Large number of samples to be taken. Count using the same method. Prevent individuals being counted more than once. Capture- recapture. Calculate a mean.
   • Laboratory investigations will include: individuals with ans without change. Measure the dependent variable. Control the independent variables. Use a range of change (Concentration) Do several repeats. Calculate mean
   1. Equations
      1. Richness

         Nota:

         • The number of species present in a habitat
         1. Evenness

            Nota:

            • Measures abundance of individuals in each species, more quantitative then richness, higher species richness, higher biodiversity, used to calculate simpsons index of diversity  
      2. Density
      3. Diversity

         Nota:

         • gg
         • If there is a high result of the diversity index, there is a high biodiversity and no development on the site should be made
   2. Random
      1. Gives representative results
      2. Gives an accurate estimate of diversity
      3. Accounts for full range of species
   3. Effective sampling

      Nota:

      • To improve a method of collecting data, you can: Collect in a different/wider area, Different times of day, Using a collecting technique such as sweet net, Ensuring you don't count individuals twice, a mark release 
      • Incorrect result occur due to: only a small number have been sampled, Individuals samples may not represent the population, individuals from one area may differ from the whole population.
   4. Methods
      1. Transect/quadrats
      2. A pooter
      3. Tullgren funnel
      4. Pitfall trap
      5. Light trap
      6. Sweep net
      7. Trees
   5. Classification / Taxonomy

      Nota:

      • Biological classification is the process of sorting living things into groups.  Natural classification does this by grouping things on how closely related they are, it reflects phylogeny.
      • Taxonomy is the study of the principles of classification, this means the differences between species.  When classifying a new species, a taxonomist needs to account for: DNA, Cytochrome c, anatomy, phylogeny, behaviour. They will compare the sequence of bases, and the more similar the sequence, the closer related the 2 organisms are.
      • When naming a species, the name needs to be in italics or underlined, and only 1st name is capitalised
      1. Phylogeny

         Nota:

         • The study of evolutionary relationships between organisms. This is often used with an evolutionary tree
         • Monophyletic- Same phylogenetic group
         1. How to determine genetic relationship
            1. Look at scientific name, same genus would suggest they're more closely related and share a more common ancestor
            2. They will have more genes in common
            3. Any physical similarities visible
            4. Differences great enough to be classed as a different species
      2. Natural classification

         Nota:

         • A hierarchy is given from how closely related species are. Modern classification is more reflectant on evolutionary distance between species and when 2 species had the same ancestor. the more recent the ancestor, the shorter the evolutionary distance. The common ancestor is dead now.
      3. Hierarchy

         Nota:

         • Organisms organised into increasingly smaller groups.
   6. Abundance

      Nota:

      • The frequency of occurrence of a species in a particular area
2. Habitat

   Nota:

   • A place where an organism lives
3. Ecosystem
4. Simpsons biodiversity index
   1. Requires list of all species in the area
   2. Number of individuals for each species
   3. A low figure
      1. Means habitat is at risk of losing species due to area not being table
5. Reasons to conserve a species
   1. Part of ecosystem
   2. Part of food chain
   3. Any useful produce?
   4. Genetic resource
   5. Potential medicine source
   6. Aesthetic value
   7. Ethical reason, the right to exist
   8. Non-medical scientific research