Biodiversity 4.2 Flashcards
What is biodiversity?
-How varied an ecosystem is
-Three types:
Genetic, Species and Habitat
What is a species and a hybrid?
-A group of organisms with similar anatomy, genes and that can interbreed to produce fertile offspring
-Different species can interbreed to produce fertile offspring (hybrid) for example a liger
What is species richness and evenness?
-Species richness: number of different species
-Species evenness: abundance of individuals in each species
Why is genetic biodiversity important for the survival of a species?
-The more genetic diversity in a species the more differences in alleles
-Species with higher genetic biodiversity are therefore more likely to adapt to changes in their environment and are less likely to go extinct
Why do researchers measure the genetic biodiversity of a population?
-Monitor species’ health and long-term survival
-Help prevent inbreeding in isolated populations like the zoo
Why would genetic biodiversity increase?
-Mutations, creating a new allele
-Interbreeding between different populations when a population migrates, this is called gene flow
Why would genetic biodiversity decrease?
-Selective breeding, only a few individuals are selected due to their advantageous characteristics
-Captive breeding, e.g. a zoo where only small number of individuals are available for breeding
-Artificial cloning, e.g. a farmer using plant cuttings
-Natural selection
What does locus mean and what and how do you measure polymorphic gene loci?
-Locus refers to the position of a gene on a chromosome
-Polymorphic genes have more than one allele
-Proportion of polymorphic genes=number of polymorphic gene loci/total number of loci
What is sampling? and how do you carry out random sampling?
-Estimating the number of individual organisms that are present in a particular area
random sampling: Put two tape measures at right angles and use a random number generator to create coordinates, count number of organisms in each coordinate, repeat and get a mean and multiply by area to get an estimate
What are the three different types of non-random sampling?
-Opportunistic: sample conveniently available organisms (weakest sampling method)
-Stratified: divide the population into groups (strata) and sample them
-Systematic: Sample different areas within the habitat separately
What is a belt transect and an interrupted belt transect?
-Belt transect: Continuous samples are taken along a parallel line (belt) using a quadrat
-Interrupted belt transect: Belt transect but instead of continuous samples the samples are at specific intervals
What is species density? and species frequency
-Species density: How many individuals of species there are per unit area
-Can be found by dividing all individuals of species by the total area of the quadrats they were found in
-Species frequency: Probability a species will be found in a quadrat in that sampling area
What is a pooter, Sweep net and a pitfall trap?
-Pooter: used to catch small insects, insects are drawn into a holding chamber as the person sucks on the mouthpiece
-Sweep net: catches insects in long grass
-Pitfall trap: used to catch small insects in a large hole too deep for insects to crawl out with a roof structure to prevent it filling with rain
What must the marking not do and assumptions in the mark, release, recapture?
-Marking must be non-toxic, not increase the chance of predation and reduce chance of reproduction
-Assumptions are that there are no deaths or births or migration
What are ways humans decrease biodiversity?
-Overpopulation
-Deforestation
-Agriculture
-Climate change
How does deforestation affect biodiversity?
-Reduces the number of trees and the number of animals as some animals use the tree as their shelter
-Even when trees are replaced it reduces species’ biodiversity as there are only a few commercially viable trees
How does agriculture affect biodiversity?
-Deforestation to increase land for crops
-Use of pesticides (pests killed are a food source)
-Removal of hedgerows (allow farmers to use machinery)
-Herbicides (reduce food source for animals)
-Depletion of minerals in the soil
Why should we maintain biodiversity?
-Aesthetic reasons (natural beauty and awe)
-Economic reasons (Non sustainable removal of timber could lead to a collapse in the industry and tourism provides economic advantages)
-Ecological reasons (Plants can contain genes which are valuable like medicines)
What is a keystone species?
-A species which has a large effect on their environment relative to their abundance
-If a keystone species is removed the habitat will change drastically
What is conservation?
-Preservation and careful management of the environment and natural resources allowing species and genetic diversity to be maintained
-Two types: in situ(within the natural habitat) and ex situ (out of the natural habitat)
How is in situ conservation carried out?
-Restricting human access, controlling poaching, reintroducing species and feeding animals
What are examples of ex situ conservation?
-Botanic gardens
-Seed banks
-Captive breeding
What is the countryside stewardship scheme?
-Farmers were paid by the government to conserve English landscape
