Classification and Evolution Flashcards
Define the term classification.
The process of placing living things into groups.
Define the term binomial system.
A system that uses the genus name and the species name to avoid confusion when naming organisms.
State the order of taxonomic levels.
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
Why does is get harder to classify organisms further up the taxonomic levels?
The further you go down the taxonomic levels it gets harder to classify where to put the organisms as it gets more specific, organisms must share many characteristics and have to be closely related. A longer description of the species may be needed to be able to place the species.
What type of evaluation is when two unrelated species that evolve in the same environment could look similar?
Convergent evolution.
What is the biological definition of a species?
Species is a group of organisms that can freely interbreed to produce fertile offspring.
Which organism does the biological definition of a species not work?
The biological definition doesn’t work for organisms that reproduce asexually and it is very hard to apply to organisms that are only known as fossils.
What is the phylogenetic definition of a species?
The phylogenetic definition of species is a group of species that are very close in appearance, anatomy, physiology, biochemistry and genetics.
Why did we move from 2 kingdoms to 5?
Once upon a time, all living things were lumped together into two kingdoms, namely plants and animals. It became very difficult to group some living things into one or the other, so early in the past century the two kingdoms were expanded into five.
Explain the use of cytochrome c in determining evolutionary relationships.
Cytochrome c is a protein that is used in the process of respiration and is in all living organisms that respire. Cytochrome c is not identical in all species. This means you can compare the amino acid chains to determine whether they belong to the same species or not.
List the common features that archaea share with Eukaryotae.
- Similar enzymes (RNA polymerase)
- Similar mechanisms for DNA replication and building RNA
- Production of some proteins that bind to their DNA
What did Darwin observe?
- Offspring appear similar to their parents
- No two individuals are identical
- Organisms can produce large numbers of offspring
- Populations in nature remain stable in size
What conclusion did Darwin make?
- There is a struggle to survive
- Better adapted individuals survive and pass on their characteristics
- Over time, a number of changes may give rise to new species
Define convergent evolution.
As adaptations are selected for by the environment, two unrelated species living in similar habitats will evolve to show very similar adaptations.
Outline the process of evolution by natural selection.
- Mutations create alternative forms of a gene (alleles).
- Creates genetic variation within the individuals of a species (intra specific variation).
- Environment selects for the characteristics that give an advantage, the selection pressure.
- Individuals with the advantageous characteristic will survive and reproduce.
- The alleles for the advantageous characteristics are passed on to the next generation.
- The next generation will have a higher proportion of individuals with the successful characteristics. Over time, the group of organisms becomes well adapted to its environment (adaptation).
