Chapter 10 - Biodiversity Flashcards
What is biodiversity
diversity of living organisms
what is the definition for a species
A group of organisms with similar features, that can reproduce together to produce fertile offspring
what is courtship behaviour with the 5 courtship behaviours
it is a necessary precursor to mating and increases the chance for successful mating by:
1. recognition of the same species
2. Synchronising mating
3. recognition of the opposite sex
4. Indication of sexual maturity/fertility
5. formation of a pair to have/raise young
what is taxanomy
the theory and practice of biological classification
what is classification
organisation of organisms into groups (taxon /taxa pl)
- classification is based on a taxonomic hierarchy
- smaller taxa are placed in larger taxa
- no overlap between taxa
example of a diagram showing the classification of a leopard
example of a taxonomic hierarchy of a tiger
Domain (largest taxon) Eukarya
Kingdom - Animalia
Phylum - Chordata
Class - Mammalia
Order - Carnivora
Family - Felidae
Genus - Panthera
Species (smallest taxon)- tigris
What are the features of the binomial naming system
Each species is identified by a binomial - two names
Uses Latin – universal language
Genus name followed by species name
Genus name always starts with a capital letter
Species name always starts with a lower case letter
Underlined if handwritten
Italics if typed
Example: Man = Homo sapiens
Homo = genus name, sapiens = species name
What is Phylogeny
It is a classification based on evolutionary origins and relationships
It is a hierarchical system - smaller groups inside larger groups
Tree like diagrams - the closer the branches the closer the evolutionary relationship.
What is biodiversity
diversity of living things. Relates to a range of habitats from a small habitat e.g. a pond, to the Earth
What is the definition of a population
all the individuals of one species living in one habitat at one time
What is a community
is all the populations of different species living in one habitat at one time
What are the two ways that biodiversity can be measured
Species richness
Species diversity index
What is species richness
the number of species in a community. Only tells us the number of different species within a community, not their distribution within species
What is species diversity index
describes the relationship between the number of species in a community, and the number of individuals in each species. Shows the distribution of individuals of species in a community. Used to compare habitats and any changes in biodiversity over time.
How do you calculate the index of diversity
d = index of diversity
N = total number of individuals of all species,
n = total number of individuals of each species
∑ = sum off
The higher the species diversity the greater the biodiversity and the more evenly spread numbers are, with no dominant species
How does agriculture affect biodiversity
- Farmers use a monoculture to increase yield and profit which will reduce biodiversity
- Farmers also use herbicides, pesticides to reduce competition and crop damage
- They also remove hedgerows to increase field size for machinery
- This removes food sources and habitats for other organisms reducing biodiversity further
what are the arguments for maintaining biodiversity
Conserve species to maintain biodiversity
Prevents habitat loss
Sources of medicine/drugs/wood – current and future
For tourism
What are the sources of genetic variation
What are the two main techniques used to measure genetic diversity
- Comparing the frequency of measurable or observable characteristics
- Automated gene technology
comparing the frequency of observable or measurable characteristics uses and limitations
- Used to identify organisms into species
- based on the idea that observable characteristics are determined by genes so can be used to determine genetic diversity
Limitations:
* Observable characteristics are determined by many genes
* Environmental modification
What are the three methods that gene technology can measure genetic diversity in order of reliability
- Comparing base sequence of DNA
- Comparing base sequence of mRNA (No introns where a lot of mutations occur)
- Comparing amino acid sequence of a polypeptide (DNA is degenerate so multiple amino acids can code of the same polypeptide
What is the definition of quantitative
Collecting numerical data
examples of investigations of quantitative phenotypic variation
height of organisms, number of prickles on holly leaves
Why should quantitative data be collected using large random sampling
- Large sample size - data is representative of the whole population
- Random sampling - reduces bias so makes data more reliable
Random sapling takes less time but only provides an estimate
Method to collect random samples
- Split area into squares.
- Generate random coordinates using a random number generator on a calculator
- Collect quantitative data at each coordinate
- repeat using a large numb er of random coordinates
How is quantitative data shown on a graph and what is on the axes
- Shown using a normal distribution curve
- shows continues variation
X axis - variable being measured
Y axis - frequency
What is the mean median and mode
Mean - the sum of all the values / the total number of values
Median - arrange all of the values in ascending order and find the middle value
Mode - most frequent value
What is standard deviation and what percentage of the data is found in one and two standard deviations (s.d.)
- spread of data around the mean
- used to reduce the effect of anomalies
- used to tell the difference between data sets is significant or not
±1 standard deviation from the mean - 68% of all measurements
±2 standard deviations from the mean - 95% of all measurements
How do you calculate standard deviation
- find the mean
- take the mean away from each value
- square each new value
- add all of these together
- divide by the total number of values - 1
- square root
What are statistical tests
- They are used to test the significance of differences/correlation
- identify the probability of results occurring by chance
( You will need to choose which statistical test to use and why.)
(You will need to interpret results from statistical tests)
What is probabiltiy
The likelihood of something happening
(decimal or percent)
What is significance
If there is less than or equal to a 5% probability that a difference or correlation is due to chance then i is said to be a significant difference or correlation.
What are the three statistical tests
Spearman’s rank
Chi squared
Student t-test
What is spearman’s rank
Used to test the significance of a correlation between two variables of paired data
E.g: investigating the relationship between light intensity and height of nettles
What is chi squared
Used to test the significance of a difference between observed and expected frequencies when data is counted in categories
E.g: Investigating the number of snails found on the north and south facing sides of a wall
What is a student t-test
Used to test the significance of a difference between the means of two sets of data when data is interval data (measured data)
E.g: investigating the height of year 7s and year 13s
What is a null hypothesis and how do they start
A staring point for every statistical test and always starts with:
There is no significant…
What is an example of a null hypothesis for spearman’s rank
There is no significant correlation between the two variables
Example: there is no significant correlation between light intensity and height of nettles
What is an example of a null hypothesis for chi squared
There is no significant difference between the observed and expected frequencies
Example: there is no significant difference between the number of snails on the N and S facing sides of the wall
What is an example of a null hypothesis for student t-test
There is no significant difference between the means of two data sets
Example: there is no significant difference between the mean height of Year 7s and Year 13s
What two events can happen at the end of every statistical test
- Accept the null hypothesis
* the difference or correlation is not significant
* there is more than a 5% probability it occurs by chance - Reject the null hypothesis
* the difference or correlation is significant
* there is a less than or equal to 5% probability it occurs by chance
Table showing all of the information about the 3 stats tests
