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| Pregunta | Respuesta |
| What is biodiversity? | Biodiversity refers to the variety of living organisms in an area |
| Biodiversity can be considered at 3 different levels. What are they? | Habitat biodiversity Species biodiversity Genetic biodiversity |
| What is a habitat? | A habitat is the area inhabited by a species. It includes the physical factors, like the soil and temperature range, and the living (biotic) factors (e.g. availability of food and presence of predators) |
| What is habitat diversity? | Habitat diversity is the the number of different habitats in an area |
| What is species? | A species is a group of similar organisms able to reproduce to give fertile offspring |
| What is species diversity? | Species diversity is the number of different species (species richness) and the abundance of each species (species evenness) in an area |
| TRUE OR FALSE The greater the species richness and species evenness, the greater the biodiversity | TRUE |
| What is genetic diversity? | Genetic diversity is the variation of alleles (versions of a gene) within a species or population of a species |
| What are the two types of sampling methods? | Random Non-random |
| What are the 3 types of non-random sampling technique? | Opportunistic Stratified Systematic |
| Describe the method of random sampling | Sample sites inside the habitat are randomly selected |
| Outline the advantages and disadvantages of random sampling | ADVANTAGE Ensures that data are not biased by selectively sampling DISADVANTAGE May not cover all areas of a habitat equally Species may be missed, leading to an underestimate of biodiversity |
| Describe the method of opportunistic (non-random) sampling | The researcher makes sampling decisions based on prior knowledge during the process of collecting data |
| Outline the advantages and disadvantages of opportunistic (non-random) sampling | ADVANTAGES Easier and quicker than random sampling DISADVANTAGES Data may be biased Presence of large/colourful species may entice the researcher to include the species (may lead to an overestimate of its importance and therefore of biodiversity) |
| Describe the method of stratified (non-random) sampling | Dividing a habitat into areas which appear different, and sampling each area separately |
| Outline the advantages and disadvantages to stratified (non-random) sampling | ADVANTAGES Ensures all different areas of a habitat are sampled and species are not under-represented due to the possibility that random sampling misses certain areas DISADVANTAGES May lead to over-representation of some areas in the sample (disproportionate number of samples are taken in small areas that look different) |
| Describe the method of systematic (non-random) sampling | Samples taken at fixed intervals across the habitat (e.g. line transect and belt transects) |
| Outline the advantages and disadvantages of systematic (non-random) sampling | ADVANTAGES Useful when the habitat shows a clear gradient in an environmental factor (e.g. getting drier further from a pond) DISADVANTAGES Only the species on the line/within the belt can be recorded Other species may be missed (underestimate of biodiversity) |
| What does the Simpson's Index of Diversity do? | Simpson's Index of Diversity (D) is a way of measuring species diversity. It takes into account both species richness and species evenness |
| What is the equation for Simpson's Index of Diversity? | D = 1 - ( ∑ ( n/N )^2 ) n = total number of organisms in one species N = total number of all organisms |
| TRUE OR FALSE: Simpson's Index of Diversity can be negative | FALSE Simpson's Index of Diversity is ALWAYS a value between 0 and 1 |
| Complete the sentence: The closer Simpson's Index of Diversity is to ____, the more diverse the habitat and the greater its ability to cope with _________ (e.g. the appearance of a new predator). The greater the species richness and ________, the ___________ the value of Simpon's Index | The closer Simpson's Index of Diversity is to 1, the more diverse the habitat and the greater its ability to cope with CHANGES (e.g. the appearance of a new predator). The greater the species richness and EVENNESS, the HIGHER the value of Simpson's Index |
| What happens when a whole population has a low genetic diversity? | They might not be able to adapt to a change in the environment and the whole population could be wiped out by a single event (e.g. a disease) |
| In which types of population would there be a low genetic diversity? | Isolated populations (e.g. those bred in captivity) Populations of pedigree animals Rare breeds |
| TRUE OR FALSE: Alleles of the same gene are always found at the same point on a chromosome | TRUE This point is called a locus (plural: loci) |
| What is polymorphism? | A locus that has two or more alleles |
| What is used to measure genetic diversity? | Genetic polymorphism Working out the proportion of polymorphic gene loci in a population gives you a measure of genetic diversity |
| What is the equation for genetic polymorphism? | Proportion of polymorphic gene loci = (number of polymorphic gene loci) / (total number of loci) |
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