Evolution and Biodiversity Flashcards
What is Evolution?
The process of things changing over time
What is the mechanism of evolution?
Natural Selection
What is the evidence for Evolution?
Fossils, Selective Breeding, Homologous Structures, Patterns of Variation,
How is the sequence of fossils important?
it matches the pattern in which they would be expected to evolve
What is the sequence of evolution?
fungi and worms -> vertebrates -> bony fish -> amphibians -> reptiles -> birds -> mammals
What is the evidence from fossils?
the sequence which fossils appear, sequence fits in with the ecology of the group, sequences of fossils
How does the sequence of fossils fit in with ecology?
plants existed before animals
how is the sequence of fossils important?
it links existing organisms and their likely ancestors
What is artificial selection?
repeatedly selecting for and breeding the individuals most suited to human uses
Why is selective breeding important to evolution?
It shows selection can cause evolution
What is a analogous structure?
structures that have had different origins and have become similar
What is convergent evolution?
analogous structures that have become similar because they perform the same or a similar function
what is a homologous structure?
structures that look superficially different and perform a different function, but which Darwin called a “unity of type”
What is adaptive radiation?
homologous structures which have similar ancestors but have become different because they perform different functions
What are vestigial organs?
reduced structures that serve no function, ie appendix, pelvis in snakes and whales
What is speciation?
populations of species gradually diverging into separate species by evolution
When can natural selection occur?
when there is variation in a species
what are the sources of variation?
mutation, meiosis and sexual reproduction
What is mutation?
production of new alleles, enlarging the gene pool
What is meiosis?
production of new combinations of alleles by breaking up the existing combination in a diploid cell.
What is sexual reproduction?
fusion of male and female gametes, offspring has a combination of alleles from two individuals which allows mutations from two individuals to be brought together
What is the only source of variation for species that do not reproduce sexually?
mutation
what is an adaptation?
characteristics that make an individual suited to its environment and way of life
What is over - production of offspring?
species tend to produce more offspring than the environment can support
What is differential survival and reproduction?
individuals that are better adapted tend to survive and produce more offspring while less adapted tend to die or produce fewer offspring
what is inheritance?
individuals that reproduce pass on characteristics to their offspring - heritable
Are acquired characteristics significant in evolution?
no
what is the binomial system?
the system used to name species, genus species
What are the three domains?
Eukaryota, Eubacteria, Archea
What are the principle taxa for classifying eukaryotes?
KPCOFGS
What is natural classification?
the genus accompanying higher taxa consist of all the species that have evolved from one common ancestral species
What are the advantages of natural classification?
identification of species is easier, members of a group share similar characteristics,
What is a Dichotomous key?
A key used to decipher the characteristics of a species
What is a clade?
a group of organisms that have evolved from a common ancestor
How do you identify base members of a clade?
the base sequences of a gene or the corresponding amino acid sequence of a protein
What is a molecular clock?
correlation between number of differences between two species and the time since they diverged from a common ancestor
What is a cladogram?
tree diagrams that show the most probable sequence of divergence in clades
What is catabolism?
breakdown of complex molecules in living organisms to form simpler ones; releases energy
What is anabolism?
synthesis of complex molecules in living organisms to form simpler ones; stores energy
What is an enzyme?
substance produce by a living organism that acts as a catalyst to bring about a reaction
What is a substrate?
surface an enzyme acts on
What is an active site?
region on an enzyme that binds to a protein or other substance during a reaction
What is an allosteric site?
where regulatory molecules interact with an enzyme to inhibit or activate that enzyme
What is a primary structure?
polypeptide chain (amino acid chain)
What is a secondary structure?
alpha helixes made of polypeptide chains
What is a tertiary structure?
alpha helixes that fold in on themselves
What is a quaternary structure?
when one or more tertiary proteins bind together
What is an exergonic reaction?
reaction where energy is lost in the reaction
What is activation energy?
energy required to start a reaction
What is dehydration synthesis?
where monomers combine to form polymers where water is a byproduct
What are the 4 macromolecules?
Proteins, lipids, nucleic acid, carbohydrates,
What are polymers?
large molecules composed of many similar smaller molecules
What are monomers?
individual small molecules
What are amino acids?
building blocks of protein
What are dipeptides?
two amino acids
What are polypeptides?
chain of amino acids, one end has an amino terminal and the other has a carboxyl group
What is a carboxyl group?
-COOH
What are fibrous proteins?
structural proteins
What is denaturation?
process of modifying the structure of a protein; breaking weak bonds
What are co-factors?
non - protein chemical compound that is required for a protein to be active
What are inhinitors?
substance that slows or stops an enzyme catalysed reaction
What are metabolic pathways?
series of steps in reactions that help convert molecules or substrates; two types (catabolic, anabolic)
What are structural proteins?
proteins used to build structural components of the body
What are functional proteins?
protein able to carry out metabolic processes
What factors affect enzyme activity?
temperature, pH, enzyme concentration, substrate concentration, presence of inhibitors and activators
What are the elements of life?
CHNOPS
What is an endergonic reaction?
reaction where energy is absorbed
What is deamination?
process which amino acids are broken down; amino group is removed
What are coenzymes?
help enzymes catalyze a reaction
