4.1.2 - Measuring Biodiversity Within A Habitat Flashcards
What Is Meant By Habitat?
Place where an organism lives.
What Is Meant By Community?
Group of populations of different species living in the same place at the same time that interact with each other.
What Is Meant By Distribution?
Describes how the species is spread throughout the ecosystem.
What Is Meant By Abundance?
The number of individuals in that space.
Why Is It Important To Measure Species Diversity?
(2 Points)
~ Compare different habitats.
~ Study how a habitat has changed over time.
What Are The Different Ways You Can Measure Species Diversity?
(2 Points)
~ Measure the species richness in an area.
~ Using an index of diversity.
The Higher The Number Of Species Means What In Terms Of Species Richness?
The greater the species richness.
What Is The Drawback Of Measuring The Species Richness?
Can be a misleading indicator of diversity as it gives no indication of the abundance of each species.
Why Do Conservationists Often Favour The Use Of An Index Of Diversity?
As it takes into account the species richness and evenness.
Why Is It Difficult To Find, Identify, & Count Every Organism In Large Ecosystems Like Rainforests, & How Is Species Estimation Conducted In Such Cases?
(3 Points)
~ Large and complex ecosystems contain a vast number of species, making it impossible to find, identify, and count every organism.
~ Samples of the area are taken to estimate total species numbers.
~ These samples are analysed to provide an approximate measure of biodiversity across the ecosystem.
What Is Used When Sampling?
Quadrats.
What Are Quadrats Used To Do?
Measure the distribution and abundance of plants.
Why Is It Important To Lay Quadrats Randomly, & How Can Random Sampling Be Achieved In An Area?
Quadrats must be laid randomly to avoid sampling bias.
How Can Random Sampling Be Achieved In An Area?
(2 Points
~ Convert the sampling area into a grid format and label each square with a number.
~ Use a random number generator to select which squares to sample.
What Are Quadrats Suitable For Sampling?
Plants.
Describe The Quadrat & Sampling Process
(6 Points)
~ Choose an area to sample.
~ Partake in random sampling.
~ Count the number of individuals in each species in the sample area.
~ Repeat the process.
~ Use the results to estimate the total number of individuals or species richness in the habitat being studied.
~ When sampling different habitats and comparing them, always use the same sampling technique.
Why Can Quadrats Not Be Used To Measure The Distribution & Abundance Of Many Animal Species?
Because they are mobile and move out of the sampling area.
What Are Other Techniques That Can Be Used To Measure The Distribution & Abundance Of Animal Species?
(3 Points)
~ Sweeping net.
~ Pitfall trap.
~ Kick sampling.
What Are Sweeping Nets Used For?
Flying insects.
What Are Pitfall Traps Used For?
Ground insects.
What Are Quadrats Used For?
Plants.
What Is Kick Sampling Traps Used For?
Aquatic animals.
What Is Genetic Diversity?
The different alleles that occur within the gene pool of a species or a population.
What Is Meant By Gene Pool?
The complete set of alleles in a species or population.
How Does Allele Variety Affect Genetic Diversity Within A Species?
The greater the variety of alleles within a species, the higher the genetic diversity will be.
Why Is Measuring Genetic Diversity Important?
(3 Points)
~ Helps investigate changes in a population over time.
~ Allows comparison between two species.
~ Provides insights into evolutionary relationships and adaptability.
How Can You Measure The Genetic Diversity Of A Species?
By looking at the phenotype and the genotype.
What Is Meant By Phenotype?
Observable characteristics of an organism.
Describe How You Can Measure Genetic Diversity Of A Species By Looking At The Phenotype
(3 Points)
~ Different alleles code for slightly different versions of the same characteristics.
~ By looking at the different phenotypes in a population of a species, you can get an idea of the diversity of alleles in that population.
~ The larger the number of different phenotypes, the greater the genetic diversity.
Describe How You Can Measure Genetic Diversity Of A Species By Looking At The Genotype
(4 Points)
~ Different alleles will have a different order of bases.
~ By sequencing the DNA of individuals of the same species, you can look at the similarities and differences in the alleles.
~ You can measure the number of different alleles a species has for one characteristic to see how genetically diverse the species is.
~ The larger the number of different alleles a species has for one characteristic, the greater the genetic diversity.
How Can You Measure The Genetic Diversity Within A Species?
Using the heterozygosity index.
What Are Heterozygotes?
Organisms that have two different alleles at a particular locus.
What Is Meant By Locus?
The position of a gene on a chromosome.
How Does A Higher Proportion Of Heterozygotes Affect The Genetic Diversity Of A Population?
The higher the proportion of heterozygotes in a population, the greater the genetic diversity of that population will be.
What Is The Formula For The Heterozygosity Index (H)?
Number Of Heterozygotes / Number Of Individuals In The Population
