Biodiversity (complete) Flashcards
(31 cards)
Define Species and Taxonomy.
- Species - a group of similar organisms that can reproduce and produce fertile offspring.
- Taxonomy - the science of classification:
> naming organisms
> organising them into groups based on their similarities.
Name the levels of classification in order from largest to smallest.
Name the thee groups in the largest, and five groups in the second largest.
Domain (Bacteria, Archae, Eukarya)
Kingdom (Prokaryotes, Protoctista, Animalia, Plantae, Fungi)
Phylum
Class
Order
Family
Genus
Species
Describe the difficulties with taxonomy.
- Species evolve over time
- Considerable variation can exist within a species.
- You can’t always see reproductive behaviours;
> Species have become extinct with no fossil record.
> They reproduce asexually. - Practical and ethical issues;
> different groups may be geographically isolated.
> can’t study them in a lab.
Name the two types of Classification.
- Artificial Classification.
- Phylogenic Classification.
Define:
- Phylogeny.
- Artificial Classification.
- Hierarchy.
- Phylogenetic.
- Phylogenetic Classification.
- Phylogeny - the study of the evolutionary relationships of a group of organisms.
- Artificial Classification - dividing organisms into groups based on differences useful at the time (e.g: leaf shape, size, colour)
- Hierarchy - large groups are grouped into smaller groups with no overlap.
- Phylogenetics - tells us who is related to who and how closely related they are.
- Phylogenetic Classification - classifying species using shared features derived from common ancestors.
Describe how you would name organisms according to the Binomial system of nomenclature.
What are the rules when writing the names?
- Latin/Greek names
- First name is generic name (Genus)
- Second name is specific name (Species)
Rules:
- Italics if printed, underlined if hand-written.
- First letter of generic name upper case.
Describe Bacteria and their features.
- A group of single-celled prokaryotes.
> the absence of membrane-bound organelles
> unicellular, although cells may occur in chains or clusters.
> ribosomes are smaller than in eukaryotic cells.
> single loop of naked DNA made up of nucleic acids.
Describe Archae and how they differ from bacteria.
- A group of single-celled prokaryotes originally classified as bacteria.
Differ because:
> their genes and protein synthesis are more similar to eukaryotes.
> their membranes contain fatty acid chains attached to glycerol by ether linkeages.
> there is no myelin in their cell walls.
> they have a more complex form of RNA polymerase.
Describe Eukarya and their features.
- A group of organisms made up of one or more eukaryotic cells, split into four kingdoms (protoctista, plantae, animalia, fungi)
> their cells posses membrane-bound organelles.
> they have membranes containing fatty acids chains attached to glycerol by ester linkeages.
> not all posses cells with a cell wall, but where they do they contain no murein.
> ribosomes are larger than in bacteria and archae.
Define:
- Biodiversity
- Species richness
- Species diversity
- Genetic diversity
- Ecosystem diversity
- Biodiversity - describes energy in the living world.
- Species richness - the number of different species.
- Species diversity - the number of different species and the abundance of each species within a community.
- Genetic diversity - the variety of genes possessed by individuals that make up only one species.
- Ecosystem diversity - the range of different habitats within a particular area.
Describe how species diversity can affect the stability of an ecosystem and how it’s affected by climate change.
- The higher the species diversity, the more stables the ecosystem and the less it’s affected by climate change.
Define:
- Population
- Ecosystem
Population - the number of the same species in the same area.
Ecosystem - all of the living and non living components of an area.
Describe biodiversity in harsh environments.
In extreme environments, the species diversity is normally low, only a few species will have the necessary adaptations to survive.
Here the ecosystem in unstable and dominated by climate factors rather than the organism within the community.
Describe biodiversity in less harsh environments.
- The species diversity is normally high in a habitat such as a rainforest.
- Here the ecosystem is stable and dominate by living organisms rather than the climate.
Describe how the species diversity of plants/producers in an area can affect the species diversity of insects, animals and birds.
Why is this?
How do you calculate species diversity. What can the size of the species diversity value tell you?
- The higher the species diversity of plants/producers in the area the higher the species diversity of insects, animals and birds.
- This is because there are more habitats, there is a large, more varied food source.
Species diversity = (N(N-1)) / sum of (n(n-1))
(where N = total number of organisms of all species and n = total number of one species)
- The higher the number, the more diverse the area is.
Why is courtship behaviour necessary in organisms?
- It enables individuals to:
> recognise members of their own species (in order to produce fertile offspring).
> Identify a mate that is capable of breeding (needs to be sexually mature, fertile and receptive).
> Choose a strong and healthy mate.
> Approach each other closely without triggering aggression.
> Form a pair bond and synchronised mating (leading to successful mating and raising of offspring.
Why do males perform such elaborate and prolonged courtship displays?
- Female needs to be sure the male is of the right species.
- Male needs to know she is receptive, and eggs are ready.
- The quality of the display may make the female more likely to choose a particular mate.
Name the beneficial reasons for maintain biodiversity.
- Ethical; humans have a responsibility to reduce their impact on the plant and other species.
- Ecological; biodiversity increases the stability of ecosystems.
- Environmental; organisms provide essential environmental services.
- Economic; a range of organisms contribute to medicine, science, ecotourism and technology.
- Aesthetic - humans take pleasure from the visual effects of biodiversity.
- Agricultural - genetically diverse wild species can rescue crops from catastrophes.
What is the impact of deforestation on biodiversity.
- Deforestation destroys habitats, causing some species to lose their shelter and/or food source. This will mean these species will either die or be forced to migrate to another area.
- This causes a loss/reduction in biodiversity.
What is the impact of agriculture on biodiversity. (give examples)
- Farmers constantly to maximise the yield they can produced from a given area of land.
> woodland clearance; to increase farmland area.
> draining ponds and installing drainage systems.
> hedgerow removal; to increase farmland area.
> monoculture (grow fields with one type of crop). - These all reduce biodiversity in the area.
> Pesticides; reduce diversity by directly killing pests and indirectly harming/killing the species that feeds on the pests.
> Herbicides; reduce plant diversity by killing weeds and indirectly killing/harming the organisms that feed on them.
Describe Artificial vs Natural fertilisers and their effects.
Artificial - made up of inorganic matter in the form of powdered or pellets that contain pure chemical components/ions.
- As the exact chemical composition is known, it’s easier to know how much to apply and the effects.
- Nutrients are more highly concentrated so small amounts are needed.
Natural - made up of organic matter in the form of dead and decomposing remains of organisms and their waste products.
- They can help improve soil structure, which helps reduce soil-erosion and increase water-holding ability.
- Nutrients from natural fertilisers are released over long time periods, and in small amounts so lots are needed.
Describe how to investigate diversity by comparing observable characteristics.
What are the limitations?
- Each observable characteristic is determined by a gene or genes.
- The variety within a characteristic depends on the number and variety of alleles of that gene (plus environmental influences)
- Limitations:
> observable characteristics are polygenic, meaning a large number of them are coded for by more than gene, meaning they vary continuously.
Describe how to investigate diversity by comparison of DNA base sequence.
- Using gene technology to read the base sequence of an organism, to compare the nucleotide sequences of two species/organisms to show how similar/different their DNA is.
- DNA sequencing (along with various techniques) can help us accurately determine the exact order of nucleotides on DNA.
- Comparison can also be done between organisms of the same species to determine how diverse they are.
Describe the process of DNA sequencing.
- Using computerised systems to tag each nucleotide base in the base sequences of DNA with fluorescent dye.
- This produces a series of coloured bands representing the four nucleotide bases.
- This allows us to measure the genetic diversity of a species by sampling the DNA of its members and produce a pattern of coloured bands.
