Biodiversity and Natural Resources Flashcards
How has the variety of life become threatened by human activity?
- Farming
- Deforestation
All reduce species diversity- causing biodiversity to fall as a result.
Define biodiversity
Biodiversity is the variety of living organisms in an area.
- Species Diversity- number of different species and the abundance of each species in an area.
- Genetic Diversity- variation of alleles within a species.
Define endemism
Endemism is when a species is unique to a single place and isn’t naturally found anywhere else in the world.
Define Population
A population is a group of organisms of the same species living in a particular area.
Why is conservation needed?
It is needed to help maintain biodiversity.
Endemic species are vulnerable to extinction. (Only found in one place so their habitat is threatened- can’t usually migrate) Numbers will decline.
Define habitat
It’s the place where an organism lives
Why is it important to be able to measure species diversity?
- Compare different habitats
* Study how a habitat has changed over time
How can species diversity be measured?
1) count the number of different species in an area. SPECIES RICHNESS IS THE NUMBER OF DIFFERENT SPECIES IN THE AREA.
Higher the number of species the greater the species richness.
2) count the number of different species and the number of individuals in each species. Then use an index of diversity to calculate the species diversity.
How does sampling of a population to estimate about the whole population work?
1) Choose a small area within the habitat to sample
2) To avoid biased results make sure that the sample is random ( ie using a random number generator for coordinates)
3) Count the number of individuals of each species in the sample area:
• plants- quadrat
•flying insects- sweepnet
•ground insects- pitfall trap
• aquatic animals- net
4) Repeat process- better indication of whole habitat
5) Results= total number of individuals or the species richness
6) Always use the same sampling technique when sampling and comparing different habitats
How can the genetic diversity within a species be measured?
1) Diversity= variety shown by individuals of that species
2) individuals of the same species vary because they have different alleles.
3) Genetic Diversity= variety of alleles in the gene pool of a species
4) Greater the variety of alleles= greater the genetic diversity
5) Can look at the PHENOTYPE and the GENOTYPE
What is the mathematical way of working out genetic diversity?
Heterozygous= two different alleles on a particular locus
More heterozygotes= population has greater genetic diversity
HETEROZYGOSITY INDEX:
H= No. of heterozygotes/ number of individuals in the population
How can biodiversity be measured?
Using an index of diversity.
D= N(N-1)/ Σn(n-1)
N= total number of ALL species n= total number of ONE species
Higher number= more diverse the area is
Same species= index is 1
• Can be used to compare the species diversity in different habitats
Define niche
• Role of a species within its habitat
- interactions with other living organisms ( preys and predators)
- interactions with the non-living environment ( O2 and CO2)
Species may compete with each other to occupy the same niche ( eg their diet which might have slight variations)
What are adaptations?
They are features that increase an organism’s chance of survival and reproduction.
How can organisms be adapted to their niches?
- Behavioural- the way an organism ACTS to increase its chances of survival.
- Physiological- Processes INSIDE THE BODY that increases an organism’s chances of survival.
- Anatomical- STRUCTURAL FEATURES of an organism’s body that increases its chances of survival.
