Biology 4.3 Flashcards
What are the eight taxonomic levels of classification in order?
-Domain, Kingdom, Phylum, Class, Order, Family, Genus and Species
What happens as you go down the taxonomic groups?
-It becomes more difficult to separate closely related species and a more detailed description is needed of the species.
What is the binomial system?
-A system that uses the genus name and the species name to name organisms
-Genus name is given as an upper case first letter
Why doesn’t the biological definition of a species work for species that reproduce asexually?
-biological definition of a species is a group of organisms that can reproduce to produce fertile offspring, organisms that reproduce asexually don’t reproduce with other organisms
-So the phylogenetic definition is a group of organisms that are similar in appearance, anatomy, physiology, biochemistry and genetics
What are the five kingdoms and a description?
-Prokaryote: no nucleus, DNA not arranged in chromosome and naked DNA(no histone proteins) and no membrane-bound organelles,
-Protoctista: Eukaryotic, single celled, plant and animal like features
-Fungi: Eukaryotic, single-celled, hyphae, walls made of chitin
-Plantae: Eukaryotic, Multicellular, autotrophic(absorb small molecules and build them up) and contain chlorophyll
-Animalia: Eukaryotic, multicellular and heterotrophic ( eat organic molecules and digest into smaller ones)
What is Cytochrome C and how can it be used to compare species?
-A protein used in respiration, the amino acids of the molecule can be identified and compared
-If the sequences are the same the species must be closely related and the more differences the less closely related they will be for example humans and chimpanzees have the same sequence.
What is the most accurate way to determine how closely related species are?
-Comparing DNA as it contains all the genetic code of the organism and the more differences the more time the two species have spent separately evolving
What is Carl Woeses’ classification system?
-Then three domain system
-He split Prokaryotes into two groups Archaea and Bacteria and eukaryotes on their own.
What is convergent evolution?
-When two species adapt to the same environment the same way and therefore look similar
What is artificial classification?
-Classification of organisms based on simple characteristics like colour
What is natural classification?
-Sorting all species into groups firstly into a small group then slowly increasing the size.
-Groups are determined by evolutionary relationships and characteristics
What is phylogeny?
-Species are grouped by common ancestry with the species with the more recent common ancestor being grouped together.
How are fossils evidence for evolution and biological molecules?
-Fossils show how new species have arisen from the old ones
-Certain Biological molecules are found in all species suggesting all species arose from one ancestor
What is intraspecific variation and interspecific variation?
-Interspecific variation: differences between species
-Intraspecific variation: differences between the individuals of a population
What is continuous and discontinuous variation?
-Continuous: Variation where there are two extremes and a range of values e.g. Height
-Discontinuous: Where there are distinct categories with no ranges e.g. gender
