Flashcards in 12 - Taxonomy Deck (18):
Definition of a species?
A group of organisms that can interbreed to produce fertile offspring
Problems with the definition of species?
- Do not know about the mating habits of some species
- Some species have never been seen to reproduce sexually and therefore can't be seen to have fertile offspring
- Some species live far apart and never have the chance to interbreed
- We can't study the breeding of fossils and therefore can't determine whether they are the same species
What are the different taxons in order?
What is a hierarchy?
A system in which large groups are split into smaller and smaller groups based on features and there is no overlap between groups
How to name a species?
Two-word name called binomial
Genus and species
Genus with capital letter, species without
Normally in italics
What is speciation?
The production of a new species when two groups of a species are seperated
What is a common ancestor?
The single species that different species evolved from
What is phylogenic classification?
The classification of species based off of their evolutionary history
What is species richness?
The number of different species that live in an area
What is species diversity?
The number of individuals in a species
What is monoculture?
Where a large area is only used for a single type of crop growing.
How do farmers reduce biodiversity?
- Weedkillers kills unwanted types of plants so that the desired crop does not have to compete - this reduces how many animals the area can sustain by reducing food sources and habitiats
- Insects killed by insecticides
How can farmers maintain bio-diversity?
- Governments give subsidies to maintain biodiversity
- Margins can be left around fields in which weeds can grow
- Stubble can be left on the fields during winter for birds to eat
- Hedges can be allowed to grow thick so that it can provide food and habitats for many animals
- Care can be taken to reduce eutrophication
- Stocking densities can be limited to reduce overgrazing and soil erosion
What is genome sequencing?
Analysing DNA to find information about genetic diversity within a population as all organisms of a species have the same set of genes on their chromosomes but different alleles and base sequences. The base sequence of mRNA produced from DNA or the amino acid sequence of proteins can be analysed to determine the DNA sequence that produced them. We can then compare how closely related the two species are to each other.
What is a good protein for comparing all eukaryotic cells?
Cytochrome c is a protein molecule in mitochondria which can be analysed to find the genetic difference between organisms
What is a discontinuous variation?
Variation that falls into distinct categories and can't be anything outside of the options such as blood types. It is caused by different alleles of genes.
What is continuous variation?
Variation across a range with no definite groups such as height. Results from many genes acting in complex ways.