What is phylogenetic classification?
When organisms are grouped based off of homologous characteristics (same evolutionary origin, regardless of function) and evolutionary relationships with ancestors
What is an ecosystem?
A place where living things interact with their non-living environment
What are the 3 main methods of conservation?
- giving legal protection to endangered species, preventing destruction of their habitat
- creating protected areas of high biodiversity, which cannot be developed
- schemes which encourage farmers to replant hedgerows and allow wildflower borders along field edges
What is a community?
A group of different species living in the same place
How are organisms named?
Through the binomial naming system, which uses their latin name for the genus and species
What are the courtship behaviours in drosophila?
- Males perform a dance - vibrating wings, altering body position and licking the female
- specific sequence of events is unique to every species, and females will not respond to a male that displays the incorrect courtship dance
What is species evenness?
How evenly spread the number of each species are within an area
What are the main harmful farming practices?
- removal of hedgerows
- creating monocultures
- filling in ponds
- draining marshlands
- over-grazing
- use of fertilisers and pesticides
How do genes control different courtship behaviour in drosophila?
Genes alter the drosophila’s brain structure and cell signalling, prompting them to respond differently to females
What is artificial classification?
When organisms are grouped based off of analogous characteristics (same function but different evolutionary origin)
What is species richness?
The number of different species within an area, but does not consider the number of individuals of a particular species
What are pesticides and herbicides?
- pesticides - sprayed on crops to kill insect pests
- herbicides - sprayed onto unwanted plants
Why do drosophila need courtship rituals?
- different species are very difficult to tell apart, but each species has their own courtship behaviour, allowing females to distinguish between them
What is the index of diversity?
Describes the relationship between the number of species in a community and the number of individuals in each species
What are agricultural ecosystems like and why?
- very little genetic diversity and allele differences
- species are chosen based on desirable characteristics, rather than focusing on being natural
- to be economically viable, the number of the desired species has to be large, meaning that it out competes all other species
What are some examples of courtship behaviour?
- male peacocks display vibrant tail feathers to attract peahens
- male cats mark their scent for female cats to smell
- male bullfrogs croak to attract females
What genes are used in biological classification and why?
Specific, vital proteins are used, because they are found in all organisms. If a mutation occurs in these proteins, it is fatal, reducing the chance of random mutations interfering with the results e.g. cytochrome C
What are the taxonomic groups in order?
Domain, kingdom, phylum, class, order, family, genus species
What are the three domains?
Bacteria, archaea and eukarya
What is a population?
A group of the same species living in the same place
How are biological molecules used in classification?
More similarities between the biological molecules, the more similar the two organisms are
What is a Chi-squared test and why would it be selected?
- looks for significant differences between observed results and the expectation
- e.g. comparing results of an actual genetic cross with the predicted ratio
What is phylogeny?
A study of evolutionary relationships between species and how closely related they are
What is a T-test and why would it be selected?
- looks for significant differenced between two sets of data for one characteristic
- e.g. comparing mean fruit weight in two different fields
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Biological Molecules - 136
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Enzymes - 19
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Cells - 148
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Immune System - 143
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DNA - 129
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Exchange Surfaces - 140
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Cell Division - 122
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Genetic Diversity and Evolution - 126
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Tricky Multi-step Processes9
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Mass Transport - 145
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Classification - 127
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Energy Transfers - 221
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Responses to Stimuli - 226
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Nervous Co-ordination and Muscles - 229
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Respiration - 221
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Inheritance - 226
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Homeostasis - 234
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Populations and Evolution17
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Control of Gene Expression - 230
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Populations in Ecosystems9
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Genetic Technologies1
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Required Practicals - Paper 28
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Required Practicals - Paper 16
