Topic- yass Flashcards
Give three ways human activity is impacting biodiversity (with examples)
Habitat destruction – e.g. deforestation for urban development and agricultural land, global warming, mining, war/conflict
Overexploitation – e.g. whaling, fishing and wildlife trade
Competition from introduced species – e.g. grey vs. red squirrels in the UK, the Nile perch vs. cichlid fish in Lake Victoria, Uganda
Pollution – e.g. micro-plastics in aquatic environments
Give three reasons why humans should preserve biodiversity (with explanations)
Ethical reasons – Humans should be responsible for the protection of the natural environment. Biodiversity should be preserved for the benefit and enjoyment of future generations
Aesthetic reasons – Many people take pleasure in walking in, or simply looking at, rich, diverse ecosystems
Economic reasons – Zoos, safari parks and other conservation sites attract tourists and can impact on local and national economies
Practical reasons – Many species provide humans with useful products and therefore have a practical, as well an economic, value
Ecological reasons – Habitat loss can therefore have a dramatic ecological effect
Define the term species
species is a group of organisms with similar morphology [appearance], physiology and behaviour, which can interbreed to produce fertile offspring,
Explain why understanding a species’ niche enables more successful conservation of that species (you can use a specific species example if this helps your explanation)
- can find out why the population is declining
can set up breeding programs
Give the definition of a species niche
Niche = the role of an organism in it’s environment and the way in which organism exploits its environment
Define the following adaptations: behavioural, anatomical and physiological. Give specific examples for each
- Behavioural: actions carried out by organism
- Physiological: internal body process within the cell, or tissues, for an organism to survive in the environment
- Anatomical: structures that can be seen when we observe/dissect an organism
Flour beetle
Decide if you are looking for:
State the 3 domains of classification
- eukaryotic
-prokaryotic
-Archaea
Explain what is meant by molecular phylogeny
an evolutionary tree measuring the difference between species in
DNA
mRNA
Protiens
Explain how molecular phylogeny enables organisms to be classified and evolutionary relationships to be identified
classifise on a molecular level instead of physical traits
can identify common ancestor and estimate how far back in evolutionary history
What is meant by the term ‘peer review’?
another scientist at a similar education level and in the same field critiquing research
List how scientists can communicate their findings to the general public and to the scientific community
scientific journals
conferences
define gene pool
All the alleles present in a population
give the definition of evolution
A change in allele frequency in a population over time
Give the conditions necessary for evolution to take place
Variation – There must be genetic differences between the individuals in a population. Meiosis and mutations provide this
⚫ Heredity – The genetic differences between organisms must be heritable
⚫ Means of selection – There must be a mechanism or pressure that selects some variables for the next generation at the expense of others.
Explain the generic principles evolution via natural selection (typical 4/5 marker, note that exam questions will provide a context in which you should frame your answer)
1) Random mutation provides genetic variation
2) Selection/evolutionary pressure occurs
3) Previously unadvantageous allele becomes advantageous
4) Organisms with advantageous allele are more likely to survive and reproduce
5) Frequency of advantageous allele increases in population
Natural selection in action
Explain why the H-W formula cannot be used for sex-linked conditions (hint: consider the XY chromosomes)
Cannot be used for sex-linked conditions i.e. those that are carried on the X chromosome
Because males carry XY combination of chromosomes, they have only one allele
Therefore, you cannot calculate p2, q2 or 2pq (the genotype frequencies)
Give the 5 conditions the Hardy-Weinburg formula is dependent upon
no selection
no mutation
no migration
large population
mating is random
define the term biodiversity
variation of organisms within a population
variation of alleles within a species
Give the formula for heterozygosity index
2pq= 1-p^-q^
Explain how heterozygosity index gives a measure of biodiversity
Give the formula for index of diversity (incl. a key)
The index of diversity of two coral reefs is calculated, the values are: 2.42 and 3.66. Explain which value shows the greatest biodiversity
3.66 shows the greatest biodiversity as it is higher due to higher species evenness compared to the total number of organisms
Define the term species richness
the number of organisms of a species in an area
define the term species eveness
Species evenness refers to how close in numbers each species in an environment is.
