Biodiversity, Species and Taxonomy Flashcards
What does Biodiversity mean?
The number of species and the number of individuals of each of the species within any one community
What does Species Richness mean?
The number of different species in community
What does community mean?
All the individuals of all the species living together in the same area at the same time
What is species?
- Group of similar organisms/ organisms with similar features / organisms with same genes
- Reproduce to produce fertile offspring
What is Genetic diversity?
Difference in DNA/ base sequence/ alleles/ genes
What does niche mean?
An organism’s role/ in the ecosystem/ community
It describes what the species is like, where it occurs, how it behaves, how it interacts with other species and how it responds to the environment
No 2 species occupy the same niche due to interspecific competition
What information is required to calculate an index of diversity for a particular community?
Number of species;
Number of individuals in each species;
The number of species present is one way to measure biodiversity.
Explain why an index of diversity may be a more useful measure of biodiversity.
Also measures number of individuals in a species / different proportions of species;
Some species may be present in low/high numbers;
Give 2 advantages of using an Index of biodiversity rather than an indicator species
You do not need to identify each species;
Index considers the number of organisms of each of the species.
Suggest one economic argument for maintaining biodiversity
- medical/ pharmaceutical uses;
- commercial products/ example given;
- tourism;
- agriculture;
- saving local forest communities;
Farmers clear tropical forest and grow crops instead. Explain how this causes the
diversity of insects in the area to decrease
- Lower diversity of plants/ few species of plants/less variety of plants/few plant layers;
- Few sources/types of food/feeding sites;
- Few habitats/ niches;
- Fewer (species of) herbivore so few (species of) carnivores;
- Aspect of agriculture (killing insects);
What are biotic factors [1]
A living factor which affects the distribution of an organism
A forest was cleared to make more land available for agriculture.
After the forest was cleared the species diversity of insects in the area decreased.
Explain why. (4)
- Decrease in variety of plants / fewer plant species;
- Fewer habitats/niches;
- Decrease in variety of food / fewer food sources;
- Aspect of clearing forest (killing insects) eg machinery, pesticides;
what is a hierarchy (2 marks)
1) smaller groups arranged within a larger group
2) no overlap between groups
Different species occupy different ecological niches
Explain the advantage of species occupying different niches (1)
1) Less competition for food
What is a population?
Group of organisms of the same species living in the same habitat
What is carrying capacity?
Carrying capacity is the maximum, equilibrium number of organisms of a particular species that can be supported indefinitely in each stable environment. Birth rates and death rates are in equilibrium
Explain what is meant by a phylogenetic group
(Grouped according to) evolutionary links/history/relationships /common ancestry
Give two ways in which courtship behaviour increases probability of successful mating
1.Attracts/recognises same species
2.Attracts/recognises mate/opposite sex
3.Indication of sexual maturity/fertility/synchronises mating
4.Stimulates release of gametes
5.Form pair bond
Give 2 ways doctors could use base sequences to compare different types of HPV
- compare DNA base sequences
- compare mRNA base sequences
- look for mutations
