Module 7 Flashcards
Natural selection
organisms with certain traits are more likely to survive and reproduce than other organisms
Evolution
change in frequency of traits in a population
Traits
introduced by random mutations
Selective pressures in the environment
determine which traits confer a survival advantage
What are antibiotics
any substance that inhibits the growth and reproduction of bacteria, or outright kills them
How does most antibiotics work
by disabling a necessary component of bacterial cells that is not found in animal cells
Bacteria
- unicellular organisms
- prokaryotic cells (simple cells with no nucleus)
- reproduce by binary fission
- fastest reproducing organisms- double every 4-20 mins
Charles Darwin natural selection idea (4)
- variation
- inherited
- overpopulation
- limited resources
Antibiotic resistance
evolution by natural selection can result in populations of bacteria that are resistant to antibiotics
The Theory of Evolution
- all living species have descended from common ancestor species, each new species have accumulated modifications that helped them survive in their habitat
- this is the unifying theory of biology and explains both the diversity and unity of life on earth
Artificial selection (selective breeding)
breeders select parents with specific traits to promote desired traits in future generations
Genetic drift
change in a frequency of traits in a population when survival and reproduction is due to chance alone
Bottleneck effect
population drastically reduced in numbers
Gene flow
exchange of genetic info between populations due to migration
Mutation
change in DNA sequence of an organism