Biodiversity Within a Community Flashcards
What is a logarithmic scale?
The values on the x-axis increases by 20 each time.
What is the advantage of a logarithmic scale?
We can see a far greater range of sizes and see more clearly if there is a correlation.
Define community
A group of interacting populations of different species living in the same species at the same time.
Define species richness.
The number of different species within a community.
Define species diversity.
The mix of different species.
Would a more common species increase the species richness?
No - some species will be more common than others but they will count up to the same extent in a species richness score (as the species richness is the NUMBER of different species in a community).
Define index of diversity.
An index giving the relationship between the number of species in a community (species richness)
And the
Number of INDIVIDUALS in each species in the community.
How can the index of biodiversity be useful?
Because biologists concerned with species diversity find it valuable to make comparisons between the diversity of trees in one habitat compared to another habitat.
What does a high index of diversity indicate?
A richer community where ideal conditions allow more species to be equally successful.
What does a lower index of diversity indicate?
Fewer successful species and it may indicate more challenging conditions such as a restricted range of good sources, fewer habitats or pollution.
What are species like in an area of low biodiversity?
In these conditions, one or two well adapted species will thrive but will dominate the community.
In what way has farming become more intensive?
More food is produced per acre.
Examples of the changes that have led to farming becoming more intensive?
Since WW2, farmers rear more productive varieties of livestock and more productive varieties of plants.
They also control insects and weeds with pesticides.
Agricultural machines have become larger and more powerful, and to work efficiently they need a large field.
What is unimproved grazing pasture like?
Especially where the land is poorly drained, it contains a mixture of more than one grass species, and a number of other flowering species - many adapted specifically to tolerate damp conditions.
What does unimproved grassland offer to others?
The different species and their different heights, flowers, leaves and seeds offers a wide range of for habitats for insects e.g. grasshoppers.
In turn these insects will provide food for insectivorous birds and mammals.
What is a biodiversity hotspot?
Remaining pockets of wet grassland in the agricultural landscape.
Define arable land.
Land used to grow crops.
Why is the rapid reduction in bumblebees causing concern?
Because bumblebees are vital pollinators of vital crops eg apples.
Why might plant species be in danger because of bees?
Because bumblebees depend on a high diversity of flowering plants as a reliable source of food. Whereas wild species depend on bumblebees for their pollination.
The biodiversity of bumblebees and plants are interlinked.
What do neonicotinoids do?
They protect young crop plants from insect pests from their start of their life.
(Estimated to have improved winter wheat yields by 20%)
How have neonicotinoids affected bees?
When neonicotinoids are used as seed treatments, they move to the pollen and nectar of the adult plants through translocation - affecting bees (by affecting their nervous system of insects, resulting in paralysis and death) as well as the target lest species.
How are species names today?
By the binomial naming system.
How does the binomial system work?
The first name is the ‘generic name’. It denotes the GENUS the organism belongs. (Similar to a surname used to identify people and shared by their close relatives).
The last name is the ‘specific name’. This denotes the SPECIES to which the organism belongs.
What are the main rules of the binomial system?
- the names are in italics (or underlined) to indicate that they’re scientific names
- the first letter of the generic name is in capitals
- but the first letter of the generic name is in lower case
- if they specific name is not known, it can be written as ‘sp’
How do organisms distinguish between all the species to know their own species?
Members of the same species have similar, or the same genes, and therefore resemble one another physically and biochemically.
Similar with behaviour, as the ability to display a behaviour is genetically predisposed.
How can organisms tell than another is part of the same species through their behaviour?
Because the ability to display a behaviour is genetically predisposed.
How does courtship behaviour achieve maximum chance of survival (through passing on their genes)?
- recognising members of their own species. To ensure mating only happens between the same species to produce fertile offspring.
- identify a mate that is capable of breeding. Because both partners need to be sexually mature, fertile and receptive to mating.
- form a pair bond. That will lead to successful mating and raising of offspring.
- synchronise mating. So that it takes place when there is the maximum probability of the sperm and egg meeting.
- become able to breed. By bringing a member of the opposite sex into a physiological state that allows breeding to occur.
What’s the purpose in courtship behaviour?
Courtship behaviour is used by males to determine whether the female is at the receptive stage.
If she responds with the appropriate behaviour response, courtship continues and is likely to result in the production of offspring.
If she is not receptive, the male turns his attention elsewhere.
What are the two names of classification?
Artificial and phylogenic classification.
What is artificial classification?
This divides organisms according to differences that are useful at the time.
Such features may include colour, size.
These are described as analogous characteristics where they have the same function but different evolutionary origins.
