Chapter 10 - Classification and Evolution Flashcards
Classification, The five kingdoms, Phylogeny, Evidence for evolution, Types of variation, Representing variation graphically, Adaptation, Changing population characteristics (36 cards)
What are the seven taxonomic groups?
Kingdom, Phylum, Class, Order, Family, Genus, and Species
What is the new level of classification in the hierarchy?
Domain - this level of classification is placed at the top of the hierarchy.
Why do scientists classify organisms?
To identify species - by using a clearly defined system of classification, the species an organism belongs to can be easily identified.
To predict characteristics - if several members in a group have a specific characteristic, it is likely that another species in the group will have the same characteristic.
To find evolutionary links - species in the same group probably share characteristics because they have evolved from a common ancestor.
What are the 3 domains?
Archaea, Bacteria and Eukarya
What is a species?
A group of organisms that are able to reproduce to produce fertile offspring.
How does the binomial nomenclature of naming work?
First word is the organisms genus, and second is its species. (written in italics or underlined, with the genus in upper case)
What is the levels of hierarchy for a human?
Eukarya, Animalia, Chordata, Mammalia, Primates, Hominidae, Homo, Sapiens
What are the five kingdoms?
-Prokaryotae(bacteria)
{prokaryotes}
-Protoctista(the unicellular eukaryotes ) {eukaryotes}
-Fungi(yeasts, moulds, mushrooms) {eukaryotes}
-Plantae {eukaryotes}
-Animalia {eukaryotes}
What are the features of Prokaryotae?
- unicellular
- no nucleus or other membrane bound organelles (ring of naked DNA and small ribosomes)
- no visible feeding mechanism
What are the features of Protoctista?
- mainly unicellular
- has a nucleus and other membrane bound organelles
- some have chloroplast
- some are sessile, but others move by cilia or by amoeboid mechanims
- nutrients are acquired by photosynthesis
What are the features of Fungi?
- uni or multicellular
- nucleus with other membrane bound orgnalles and cell wall made of chitin
- no chloroplast
- no mechanism for locomotion
- most have a body or mycelium made of threads or hypae
- most store their food as glycogen
What are the features of Plantae?
- multicellular
- all contain chloroplast
- most dont move
- nutrients are acquired by photosynthesis(autotophic)
- store food as starch
What are the features of Animalia?
-Multi cellular
-no chloroplast
move with aid of cilia, flagella, or contractile proteins sometimes in the form of muscular organs
-nutrients are acquired by ingestion (heterotrophic)
-food stored as glycogen
What is the current classification system used by scientists?
The Three Domain System. Proposed by Carl Woese (microbiologist)
The system organises organisms based on differences of nucleotides in the cells ribosomal RNA as well as cells membrane lipid structure and their sensitivity to antibiotics.
What is the Prokaryotae kingdom divided into in Woeses system?
Archaebacteria and Eubacteria - this will mean there will be 6 kingdoms
What is Phylogeny
Phylogeny is the name given to the evolutionary relationships between organisms. The study if the evolutionary history pf groups of organisms is known as phylogenetics.
what sources do scientists use to study the process of evolution?
- Palaeontology = the study of fossils and the fossil record
- Comparative anatomy = the study of similarities and differences between organisms anatomy
- Genetics
What are fossils?
They are formed when animal and plant remains are preserved in rocks.
What is the fossil record?
They’re formed when animal and plant remains are preserved in rocks. Within different rock strata the fossils found are quite different, forming a sequence from oldest to youngest, which shows that organisms have gradually changed over time. Study of fossils = palaentology
How do fossils show evidence of evolution?
- simplest organisms such as bacteria are in the oldest rocks, whereas complex organisms are found in more recent rocks
- Sequences in which organisms found match their ecological links. eg. plant fossils appear before animals
- Similarities in anatomy
- Fossils allow relationships between extinct and living organism to be investigated
\whats a homologous structure?
a structure that appears superficially different (and may perform different functions) in different organisms, but has the same underlying structure. An example of this is the pentadactyl limb of vertebrates.
What is divergent evolution?
The presence of homologous structures provides evidence for divergent evolution. This describes how, from a common ancestor, different species have evolved, each with a different set of adaptive features.This type of evolution will occur when closely related species diversify to adapt to new habitats as a result of migration or loss of habitat.
What is Comparative biochemistry?
The study of similarities and differences in the proteins and other molecules that control life processes. Two most common molecule = cytochrome c (protein involved in respiration) and ribosomal RNA
Whats the hypothesis of neutral evolution?
The hypothesis of neutral evolution states that most of the variability in the structure of a molecule does not affect its function. This is because most of the variability occurs outside of the molecules functional regions, changes that do not affect a molecules function are called ‘neutral’. - since they do not effect the function, their accumulation is not affected by natural selection. As a result, neutral substitutions occur at a fairly regular rate.
- Two discover how closely two species are related, the molecular sequence of a particular molecule is compared. The number of differences that exist are plotted against the rate the molecule undergoes neutral vase pair substitutions.
