Biodiversity Flashcards
Explain the difference between ‘species richness’ and ‘species evenness’. (2)
- Species richness: number of species living in a particular area. (1)
- Species evenness: the distribution and proportions of each species in a community. (1)
There are different ways (or levels) that biodiversity can be studied. Name three ways. (3)
- Habitat biodiversity; (amount of different habitats within an area). (1)
- Species biodiversity; (species richness and evenness). (1)
- Genetic biodiversity; (variety of genes making up a species, varying alleles). (1)
Explain the effect that a larger sample size has on the reliability of data collected.
It is less likely that chance will influence the results (1), as with more specimens the data is less likely to not be representative. (1)
Provide short explanations of the following sampling techniques: pitfall traps, pooters, sweepnets. (3)
- Pitfall traps; catches small, crawling invertebrates in a hole dug in the ground. (1)
- Pooters; catches small insects by a person sucking into a mouthpiece, drawing them into a tube. (1)
- Sweepnets; catching insects in tall grass. (1)
Describe how line transects work. (3)
Describe how belt transects work. (3)
- Measuring tape in a straight line. (1)
- At regular intervals, species that touch the line are recorded. (1)
- Qualitative data is produced. (1)
- Quadrats are placed at regular intervals along the measuring tape. (1)
- The abundance of species is recorded. (1)
- Quantitative data is produced. (1)
What does a higher Simpson’s index of diversity value indicate? (1)
A greater biodiversity, taking into account both species richness and evenness. (1)
What is a polymorphic gene? (1)
Do polymorphic genes make up the majority of the genome? (1)
A gene with more than one allele. (1)
No, most are monomorphic. (1)
How do we use the amount of polymorphic gene loci (a locus being the position of a gene on a chromosome) to estimate genetic biodiversity within a population? (2)
Proportion of PM gene loci = Number of PM gene loci/Total number of gene loci (1)
A higher value indicates a larger genetic biodiversity. (1)
Explain how deforestation affects biodiversity. (4)
- Directly reduces the number of trees. (1)
- Some species of trees are targeted (reducing species richness and evenness). (1)
- Disrupts food webs by destroying habitats and food sources (1) and as species migrate due to this, other species suffer as well. (1)
Explain how agriculture affects biodiversity. (4)
- Deforestation may occur to provide land for crops and animals. (1)
- Hedgerows are removed (reducing habitat biodiversity) to maximise the amount of land for agriculture. (1)
- Pesticides kill pests, directly reducing species biodiversity and disrupting food webs. (1) (Something similar can be said about herbicides).
- Monocultures (farms that specialise in a single crop) drastically decrease species biodiversity. Only one plant species is present that can only support a limited amount of animal species. (1)
Explain how climate change affects biodiversity. (4)
- Rising sea levels can flood low-lying land, reducing terrestrial habitats. (1)
- Higher temperatures/less rainfall could lead to drought-resistant species (e.g xerophytes) becoming more dominant. (1)
- Tropical insects (that carry pathogens) may begin to spread, spreading disease to new areas. (1)
- Insect life cycles will be affected. As pollinators, this will have a knock-on effect on plants, as the range of the insect changes. (1)
Give one ecological reason, one aesthetic reason and one economical reason for maintaining biodiversity.
Ecological:
- Organisms are interdependent on eachother. The absence of a species will affect the entire ecosystem. (1)
- The removal of a keystone species (a species with a disproportionately large role within their ecosystem, relative to their abundance) will dramatically change an ecosystem. (1)
Aesthetic:
- The presence of diverse plant/animal species enriches day-to-day life. (1)
- Many artists use nature in their works, drawing inspiration. (1)
- Studies suggest that patients supported by an environment with a rich biodiversity recover more rapidly (injuries or stress). (1)
Economical:
- Practices (e.g deforestation) can lead to desertification or soil erosion, decreasing land that we can grow crops on, leading to economic dependence on other nations. (1)
- Non-sustainable methods in industry could lead to collapse, so conservation is necessary for these industries to continue. (1)
- Species that may have economical uses may go extinct before they are discovered due to losses in biodiversity. (1)
- Areas with abundant biodiversity are more attractive to tourists. (1)
Explain the difference between in situ conservation and ex situ conservation. (1)
In situ conservation is carried out within the habitat, while ex situ conservation is done out of the native habitat. (1)
Order the following phrases from least severe to most severe (1):
- Extinct in the wild
- Vulnerable
- Endangered
- Extinct
- Vulnerable
- Endangered
- Extinct in the wild
- Extinct
Explain the purpose of The Convention on International Trade in Endangered Species (CITES). (2)
Safeguards certain species from being over-exploited (1) by regulating international trade of animal and plant specimens. (1)
