U3T૧ - Classification & Biodiversity | Marc Flashcards
What are biological classifications based on?
Similarity of physical features
> Presences of wings, fur, scales etc.
Methods of Reproduction
> Sexual vs. Asexual
Molecular sequences
> Similarity of DNA
Why is there a need for multiple definitions of a species
Because the inherent definitions of a species all have limitations for each concept.
-Similarity of physical features-
> Some species may look very similar but be completely different species or Look extremely different but be the same species.
-Reproductive Methods-
> Focus on interbreeding and able to reproduce but falls short for asexual reproduction such as bacteria
-Molecular Sequences-
>Some species may be genetically similar but be completely unrelated
Identify one interspecific hybrid which cannot reproduce fertile offspring.
Mule - Horse and Donkey
Liger - Lion and Tiger
Describe the classification system of asexual vs. sexual
Asexual is 1 parent with no variation in offspring (usually bacteria)
Sexual is 2 parents with variation using both parents DNA
Describe how Phylogenetics are used in classification systems
Phylogenetics compares organisms genetic sequencing and molecular structure to classify evolutionary relatedness
Explain the interactions seen in mutualism, competition, predation, parasitisms, commensalism, ammensalism.
-Mutalism [ +/+ ] Both benefit.
-Competition [ -/- ] Both get negatively impacted due to lack of resources.
-Predation [+/-] The predator benefits, prey negative.
-Parasitism [+/-] The parasite benefit, host negatively.
-Commensalism [+/0] One benefits the other is uneffected
-Ammensalism [-/0] One is uneffected one is negatively effective.
What are the 3 common assumptions of cladistics
Common Ancestry»_space;> They all descend from a common ancestor.
Bifurication pattern»_space;> Cladistics assume there is a pattern where they divide by 2.
Physical changes»_space;> Assume physical changes occur over time.
How would you use molecular evidence in finding common ancestory?
The greater number of differences in a DNA sequence can determine how long ago they shared common ancestory
What are the levels of organisation
Biosphere»_space;> Ecosystem»_space;> Community»_space;> Population»_space;> Organism
What are ecosystems composed of (in terms of habitats)
Microhabitats to Ecoregions.
Microhabitats are very small habitats.
Ecoregions are ecosystems covering a large biogeographical area.
Explain the importance of Old Growth Forests.
Old Growth forests provide the following in their given ecosystem.
- Habitats for many endangered species
- Holds many animals such as birds, bugs and bacteria.
- If logged many species would die causing increased chance of extinction
- If logged millions of CO2 particles to be released into the atmosphere OH NO GLOBAL WARMING :(
Why is it important to maintain productive soil?
Productive soil is crucial because…
- It is highly biodiverse, allowing for bacteria, fungi, worms and bugs to inhabit the soil
- Good soil allowing for physical and chemical properties to promote healthy plant life allowing for humans and animals to consume
- Assists in the nutrient and nitrogen cycling
- Overuse can cause animals to die, and does not promote plant growth
Why are coral reefs important in the ecosystem?
Coral Reefs are important because…
- It provides a habitat for many fish (ie. clownfish)
- Protects coasts from storms, erosion and is significant in indigenous culture
- Keeps the currents stable
What is stratified sampling?
Breaking down a large propulation into subgroups known as strata
What is the purpose of stratified sampling?
To make estimates about the population as a whole.
Estimates include:
- Population Density
- Distribution
- Environmental gradient/profiles
- Zonation
- Stratification
Why is fair site selection important?
Site’s must be selected from each strata which is fairly homogenous and is able to reporessent the whole population
What are some methods to ensure fair site selection?
- Randomisation methods such as random number generators
- Adequate number of samples, the more samples the better representation of the population
- CLEAR marking of site to see effect over time (human effect)
What do transects measure?
Changes in distribution and abiotic factors
What do Quadrats measure?
Density of a population
Why is choice of surveying technique important?
To correct relevant data to a given situation.
How can transects and quadrats be used together?
To draw conclusion of environmental gradient, zonation or stratification.
How do you minimise bias?
Law of Large Numbers
- Greater number of samples = greater probability that theyrepresent a population.
Random number generator
- Used to pick sites in a grid based coordinate.
Counting criteria
- Establish clear parameters causing consistent results
Calibrate equipment
- Regularly calibrate equipment to ensure consistent results
- Acknowledge precision of equipment
What is biodiversity
Biological diveristy, which is the variety of organisms living in an ecosystem
Why measuring biodiversity important?
As it can help determine the wellbeing of an ecosystem
