Topic 4: Natural Selection and Genetic Modification Flashcards
Who is Alfred Russel Wallace?
A scientist that came up with the idea of natural selection, independently of Darwin. Although his proposed mechanism differed, his observations provided further evidence to support the theory.
What are antibiotic-resistant bacteria?
Bacteria that mutate to become resistant to an antibiotic, survive and reproduce very rapidly, passing on their antibiotic resistance.
What are Archaea?
One of the three domains. It consists of primitive bacteria existing in extreme environments.
What is Ardi?
A 4.4-million-year-old female hominid fossil that shows phenotypic traits encompassing characteristics of both humans and apes.
What is Bacillus thuringiensis (Bt)?
A soil-borne bacterium which secretes a toxin that kills insect larvae. The gene for toxin production in Bt can be introduced into the DNA of crop plants to provide insect resistance.
What are Bacteria?
One of the three domains that consists of true bacteria.
What is biological control?
The introduction of a new organism (often a predator) into an ecosystem to control a pest or pathogen.
What is carbon-14 dating?
Estimating the age of carbon-containing material that is found in or alongside archeological remains in order to determine their age.
Who is Charles Darwin?
The scientist who developed the theory of evolution by natural selection.
What is classification?
The organisation of organisms into groups based on their characteristics and structure.
What is competition in an ecosystem?
When different organisms compete for the same resources (e.g. light, water, mates, territory) in an ecosystem. This limits population size and stimulates evolutionary change.
What is Eukarya?
One of the three domains that consists of all eukaryotic organisms.
What is evolution?
The gradual change in the inherited traits within a population over time. Occurs due to natural selection.
What are fertilisers?
Natural or artificial materials that are added to soils to provide essential nutrients and improve plant growth.
What is the five kingdom classification system?
The classification of organisms into five major kingdoms: Animalia, Fungi, Plantae, Prokaryotae and Protoctista.
What are fossils?
The remains of dead organisms found in rocks which are millions of years old.
What is a genetically modified (GM) organism?
An organism that has had its genome altered.
What is genetic engineering?
The modification of the genome of an organism by the insertion of a desired gene from another organism, enabling the formation of organisms with beneficial characteristics.
What is a genome?
The complete genetic material of an organism.
What is ligase?
An enzyme that joins the sticky ends of the DNA and vector DNA forming recombinant DNA.
Who is Lucy?
A 3.2 million year old female hominid fossil exhibiting more human-like phenotypic traits than ‘Ardi’.
What is a mutation?
A random change in the base sequence of DNA which may result in genetic variants. Mutations may be beneficial, damaging, or neutral.
What is natural selection?
The process by which the frequency of advantageous traits passed on in genes gradually increases in a population over time.
What is a pentadactyl limb?
A limb with five digits present in animals, birds, reptiles and amphibians. It provides evidence for the evolution of species from a common ancestor.
What is recombinant DNA?
A combination of DNA from two different organisms.
What are restriction enzymes?
Enzymes that cut DNA molecules at specific sequences, creating sticky ends.
Who is Richard Leakey?
A scientist that discovered many hominid fossils on an expedition to Kenya, including the 1.6-million-year-old fossil ‘Turkana Boy’ which showed traits comparable to that of modern-day humans.
What are selection pressures?
Environmental factors that drive evolution by natural selection and limit population size, e.g. competition, predation and disease.
What is selective breeding?
The process by which humans artificially select organisms with desirable characteristics and breed them to produce offspring with desirable phenotypes.
What are sticky ends?
The staggered cut formed by restriction enzymes in double-stranded DNA.
What is stratigraphy?
Using the age of the layers of sediment surrounding archeological remains to estimate the age of the remains.
What is taxonomy?
The classification of organisms into taxa: kingdom, phylum, class, order, family, genus, species.
What is the three-domain system?
A method of classification in which organisms are categorised into three groups: Archaea, Bacteria and Eukarya. Developed by Carl Woese.
What is tissue culture?
A method of growing living tissue or cells in a suitable medium to produce clone plants.
What is a vector?
A carrier used to transfer a gene from one organism to another.
