Chapter 10- Biodiversity Flashcards
Define species
A group of similar organisms capable of interbreeding to produce fertile offspring
Define taxonomy
Organisms are classified into groups each group is called a taxon. Taxonomy is the study of these groups or taxa
Define classification
Organising the variety of life based on relationships between organisms
What is binomial naming system ?
A common system advised to name organisms
What is the binomial naming system ?- describe how it works
The first name is capitalised and is the generic name - the genus
The second name is lowercase and is specific - the species
If handwritten it is underlines
If printed it is italics
Each group within classification is called a
Taxon
A domain is the —— ——- rank and the 3 domains are —— —— —-
Highest taxonomic rank
Bacteria
Archaea
Eukarya
What are bacteria?
Name 3 features
A group of single - celled prokaryotes with the following features
Unicellular
Small ribosomes - (70s)
No histones and loops of nucleic acid
What are archaea ?
Name 3 features
A group of single celled prokaryotes which were originally classified as bacteria but differ because
Their genes and proteins synthesis are more similar to eukaryotes
Their membranes contain fatty acids chain attached to glycerol by ester linkages
Their is no murein in their cell walls
What are eukarya - give 3 features
A group of organisms made up of 1 or more eukaryotic cells with features of:
Membrane bound organelle
Larger ribosomes (80s)
Can contain well walls but non are made of murein
What are the 4 eukarya kingdoms?
Protoctista
Fungi
Plantae
Animalia
What are the classification sections ?
Domain Kingdom Phylum Class Order Family Genus Species
How are organisms classified?
Similarities in DNA and proteins
Similarities and characteristics
What is a phylogenetic tree and how is it read?
It shows the evolutionary relationships between organisms
The closer the branches the closer the evolutionary relationship
Members of the same species have similar or the same —— and therefore …
Genes
Resemble one another physically and biochemically
How does courtship behaviour ensure there is successful reproduction?
Allows them to recognise members of their own species
Identify a mate that is capable of breeding
Form a pair bond
Synchronise mating
Become able to breed
Define biodiversity
The general term used to describe variety in the living world
Define species diversity
The number of different species AND the number of individuals of each species within any one community
Define community
All the living organisms present in an ecosystem at a given time
Define species richness
The number of different species in any one community at a given time
Define genetic diversity
The variety of genes possessed by the individuals that make up a population of 1 species
Define ecosystems diversity
The range of different habitats in a community at a given time
How do you calculate an index of diversity?
d = N(N-1)
The sum of n(n-1)
What does N mean in the index of diversity calculation?
The total number of organisms of ALL species
What does n mean in the index of diversity calculation?
The total number of organisms of EACH species
Why is using the index of diversity preferable to just recording the number of species present?
It tells you the number of individuals of every species so it takes into account species present in small numbers
It is also more easily comparable and easier to interpret
Do natural communities have a high index of diversity or a low index of diversity? Why?
High because the ecosystem develops over time and they become more COMPLEX with many individuals of a large number of different species
Do agricultural ecosystems have a high index of diversity or a low index of diversity?
Why?
A low index of diversity because farmers select species with particular properties so the genetic variety of alleles is reduced to the few that have the desired properties. To be economic the number of these individuals needs to be large so species that are not desirable are removed
Explain the direct negative impacts of agriculture
State 3
The removal of hedgerows and grubbing out woodland removes habitats
Creating monocultures reduces diversity
Filling in ponds and draining wetlands removes habitats
Overgrazing of land prevents regeneration of woodlands
State 3 indirect negative impacts of agriculture
Use of pesticides and inorganic fertilisers reduces diversity
Absence of intercropping and crop rotation leads to less nutrients in the soil and reduces diversity
Escape of effluent from silage stores into water sources kills species and therefore reduces diversity
List 10 positive conservation techniques that farmers should utilise
- Plant hedges rather than fences for boundaries
- Make and keep ponds
- Use organic fertilisers
- Use less pesticides
- Use crop rotation with nitrogen fixing crops
- Use intercropping rather than herbicides to control weeds
- Create natural meadows using hay rather than grasses
- Introduce conservation headlands where pesticides cant be used
- Maintain ideally shaped hedgerows
- Leave wet corners of fields rather than draining them
What were the original use of hedgerows?
To create boundaries of fields and contain livestock
Explain why farm sizes have had to increase recently
Because of machinery, more can be done so bigger fields are maintainable and to fit the machines bigger fields are needed
Why are hedgerows being removed ?
To allow space for machinery and increase crop yield by using all the land to produce the crops
Grants were available for the most productive land areas
Why are hedgerows ideal to keep?
They increase species diversity and act as corridors for animals to move.
Provide habitats and food sources
Which has more consequences if removed? A hedgerow or a pond?
Why?
A pond because they provide water to many species and also provide food and habitats to many species, whereas hedgerows only provides food and habitats
Also ponds are more sparse and less prevelant so if removed habitats would be harder to find. Many of the species in a pond would be unable to relocate
What are the 3 ways to investigate diversity?
Compare measurable or observable characteristics
Compare base sequences of DNA
Compare protein sequences of species
