Topic 4

• Species richness is the number of different species in a community, while index of diversity describes the relationship between the number of species in a community and the number of individuals in each species.
• Local biodiversity refers to the variety of species living in a small habitat such as a pond or meadow, while global biodiversity refers to the variety of species living on Earth.
• The index of diversity is a more useful measure of species diversity than species richness as it also measures the number of individuals in a species.
• Genome sequencing compares the order of base sequence of whole genome of different species, with a higher % match indicating a more closely related species.
• Immunology techniques can be used to compare the proteins of different species, with the secondary structure of a protein revealing the sequence of DNA.
• Synodontis batensoda is the species most closely related to Synodontis membranacea.
• Farming techniques such as removal of woodland and hedgerows, monoculture, use of pesticides, herbicides and inorganic fertilisers can reduce biodiversity.
• If the same antibody binds to a specific antigen, it is closely related.
• Habitat refers to the places where an organism lives, while community refers to all the populations of different species in a habitat.
• There are 5 different genera shown in the diagram.
• Each species is universally identified by a binomial consisting of the name of its genus and species.
• Biodiversity refers to the variety of living organisms in an area, with three components: species diversity, genetic diversity, and ecosystem diversity.
• Use crop rotation of nitrogen fixing crops instead of fertilisers, maintain existing hedgerows and plant new hedges instead of using fences, reduce the use of pesticides.
• Some conservation techniques can be applied that increase biodiversity without unduly raising food costs or lowering yields, for example…
• Continuous variation has no distinct categories and is quantitative, controlled by many genes and strongly influenced by the environment, for example: height.
• Variation within a species could be the result of genetic factors, environmental factors, or a combination of both.
• Discontinuous variation has distinct, discrete categories and is qualitative, controlled by a single gene or a few genes and unaffected or not strongly influenced by the environment, for example: blood groups.
• The demand for increased food production has led to areas of heath being used to grow wheat, reducing the species diversity of plants and animals.
• Genetic diversity within, or between species, can be made by comparing the frequency of measurable/observable characteristics, indicating genetic diversity because different alleles determine different characteristics.
• Genetic diversity is the number of different alleles in a population.
• Farmers clear tropical forest and grow crops instead, causing the diversity of insects in the area to decrease.
• Gene technologies have made it possible to directly obtain DNA sequences.
• Humans need to make a balanced judgement between the demands for increased food production due to a rapidly growing human population, and the need to conserve the environment.
• Many spores are released nearby, so more of the nutrient source is used and it is used more rapidly.
• Variation of alleles exists in a population due to random DNA mutations.
• Natural selection results in better adapted species, with adaptations that increase an organism’s chance of survival and/or reproduction.
• Adaptations can be anatomical, physiological, or behavioural.
• There is a positive correlation between the size of snow geese and how far north they breed, as a large size results in snow geese being adapted for breeding in colder conditions.
• Selection pressure or change in environment can lead to differential survival or reproductive success.
• The further north a breeding colony forms, the colder the temperature and the greater the risk of snow.
• The fungus produces genetically identical fungi, so all are well suited to the nutrient source and environment.
• The spores vary genetically due to independent segregation, crossing over, and mutation or change in base sequence of DNA.
• A population is a group of interbreeding individuals of the same species.
• Snow geese fly north to the Arctic in the spring and form breeding colonies at different latitudes.
• In the second stage of meiosis, separation of chromatids occurs, so the chromosome number remains constant and two haploid cells go to four haploid cells.
• The arrow labelled M2 represents the second division of meiosis, where the chromosome number is halved from 2n to n.
• The greater the latitude, the further north is the colony.
• Proteome: The full range of proteins that a cell /genome is able to produce.
• The further north, the greater the risk of snow, with snow lying longer and melting slower further north, resulting in white geese being better camouflaged and predation being linked to survival and reproductive success.
• The scientists concluded that an increase in phosphate in the embryo was linked to growth of the embryo, with a increase in phosphate required for the creation of RNA, DNA, ATP/ADP, membranes, and for phosphorylation.