Describing Biodiversity
This formula is used to calculate Diversity in ecosystems
Simpsons Diversity Index
Which trophic level does a primary consumer occupy?
Second
Identify the complementary DNA strand
TAG CCA GTC
ATC GGT CAG
Small-scale variation of allele frequencies within a species or population in which the descendant is of the same taxonomic group as the ancestor.
Microevolution
What is the function of a HOX gene?
HOX genes encoding transcription factors that act as master control switches during embryonic development. They switch on/off blocks of genes that control body shape, limb development etc.
This species is characterised by having only a few offspring but investing high amounts of parental care
K- Selected Species
Define Keystone Species
A keystone species is a species that has a disproportionately large impact on the environment relative to its abundance
a) What process results in the production of four haploid cells and what are those cells called?
b) Describe the processes that generate genetically unique cells
Meiosis produces gametes
Crossing over (Prophase I) exchanges blocks of genes between homologous chromosomes
Independent assortment (Metaphase I) lining up with either paternal or maternal chromosomes on left) results in differing combinations of mostly maternal/paternal chromosomes in each gamete.
This mode of speciation occurs when a physical barrier separates populations, preventing gene flow.
Allopatric speciation
Estimate the population size from the following information:
An overnight light trap caught 20 hawk moths which were dye-marked and released.
The following night, the same trap caught 15 hawk moths, 5 of which were marked.
N = (Mxn)/m
N = (20 x 15) / 5 = 60
What mnemonic do we use to remember the Linnean system of classification? What does it stand for?
Dear King Philip Came Over For Great Spaghetti
Domain Kingdom Phylum Class Order Family Genus Species
Define carrying capacity
The maximum population size of a biological species that can be sustained by that specific environment, given the food, habitat, water, and other resources available
What is the purpose of PCR
To amplify specific segments of DNA
This type of natural selection favours the average phenotype and reduces variation in a population
stabilising selection
Compare parapatric and sympatric speciation.
Both processes were speciation occurs without a physical barrier between populations.
Parapatric occurs at the edge of an area, due to gene flow mainly occuring with near neighbours and may involve a change in environmental conditions at the edge (eg. climate, food sources etc.)
Sympatric occurs within a gegraphic area, due to some form of reproductive isolation due to genetic mutation, bevavioural changes (eg. mate selection)
A group of organisms that consists of a common ancestor and all its lineal descendants
Clade
Explain how carrying capacity is limited by food availability
There may not be enough food for the whole population, causing some organisms to die off, therefore changing the carrying capacity of the population.
What is the role of Helicase in DNA replication
To unzip the DNA strand by breaking hydrogen bonds
This pattern of diversification occurs when two unrelated species develop similar traits because they live in similar environments
Convergent evolution.
Define "the Founder Efffect" and explain it's significance for evolution
Reduced genetic variety when a small group of individuals separates from the main population.
This may lead to genetic drift, when random events result in significant changes in allelic frequency (compared to the original population).
What 2 measurements is Spechts classification based on?
Ground/canopy cover and height of the tallest stratum
Explain primary and secondary succession
In primary succession, newly exposed or newly formed rock is colonised by living things for the first time. In secondary succession, an area that was previously occupied by living things is disturbed, then re-colonised following the disturbance
Down syndrome is caused by Trisomy 21.
Explain the term Trisomy 21
Trisomy occurs when there are three copies of a chromosome instead of the normal two. 21 indicates that this copying error has occurred on the 21st chromosome
A population of birds was observed to have individuals with very short and very long beaks, with very few birds observed with medium sized beaks.
What type of selection is shown here?
Disruptive selection
Describe the steps in production of mRNA
1) RNA polymerase binds to gene promoter and makes an RNA copy (pre-mRNA) of the coding sequence.
2) Splicing to remove introns (non-coding) and join exons (coding) together.
3) Addition of a 5' CAP and 3' ploy(a) tail