B6 Flashcards
what is a gene
short section of DNA that codes for a characteristic
what is a genome
complete set of DNA for an organism
what are the uses of mitosis
growth, development, repair
how does variation happen?
through mutations
what are the types of mutations
deletion, insertion, duplication and substitution
what is adaptation?
special characteristics or behaviours that make an organism suited to their habitat which improves chances of survival and reproduction
what is evolution
a change in the inherited
characteristics of a population over a number of
generations through a process of natural selection
which may result in the formation of new species
what is variation
difference between species
what are fossils
the remains of an organism that lived a very long time ago
what do fossils show us
- how organisms changed - throughout the past
- evidence for evolution
- lets us see small incremental changes
what are some problems with fossils?
- some organisms are soft bodied and don’t fossilise well
- some fossils formed a long time ago could have been destroyed
–> could be through earthquakes or volcanoes
what modern evidence is there for evolution
antibiotic resistance, especially MRSA
how does antibiotic resistance work
*bacteria is killed by antibiotics but some go through a mutation in their DNA, causing the bacteria to become resistant to antibiotics
*normal bacteria are killed but the mutated ones survive and reproduce
*the amount of this increases, meaning the bacteria has evolved
what happens if a genetic variant affects the phenotype?
it can give rise to different characteristics that make an organism better suited to its environment
what is natural selection?
a process where organisms that are better adapted to an environment will survive and reproduce. This means that the advantageous alleles of this variant organism are passed on to offspring. Over many generations, the process of natural selection leads to evolution occurring
what is speciation?
the formation of new species
when can speciation happen
when there is a physical barrier isolating the two populations
why is breeding done
maximum yield, good health, disease resistance, fertility
how is breeding done?
*parent organisms are selected and bred w each other
*the best of the offspring are bred
*the process is repeated to get the desired traits
what does selective breeding do to the gene pool
reduces it
why does inbreeding happen
breeding the best individuals together
what can inbreeding lead to
health problems from genetic disorders
new diseases: everyone will be at risk
what is classification of organisms
grouping organisms based on their similarities and differences
what is the classification system?
Kingdom
Phylum
Class
Order
Family
Genus
Species
mnemonic
King Phillip Came Over For Good Soup
What does DNA tell us about classification?
*they check the genomes, looking for similarities(the same number of genes)
*if diff organisms have the same number of genes, its likely they had a common ancestor
* the more similar the sequences are, the more closely related they are
what can dna analysis tell us
suggest whether different groups have a common ancestor, and how recently speciation occurred
what is biodiversity
diversity of living organisms, different genes and different ecosystems
what changes have reduced biodiversity?
increasing human population, industrialisation, globalisation
how can these changes damage or destroy ecosystems
habitat destruction
waste
sharing resources
how can we prevent the loss of biodiversity
by having sustainability
what is sustainability
meeting the needs of the population without harming the environment so it can be used for future generations
3 ways of protecting biodiversity through conservation schemes
- protecting specific species
- protecting habitats and
ecosystems - preventing ecosystem
damage on a global scale
protecting specific species
-ban the hunting of them
- keep them in safe areas, away from harmful activities
-breeding programmes to increase the number
protecting habitats and ecosystems
setting aside specific protected areas by preventing land development
protecting ecosystem damage on a global scale
climate change and global warming
- reduce greenhouse gases
how does maintaining biodiversity help humans too?
protects food supply - overfishing
ensuring minimal damage to food chains - one species going extinct affects the whole food chain
provides future medicines - rainforest destruction
providing industrial materials and fuels - wood + deforestation
economic issues maintaining biodiversity
- can be expensive
- could affect countries ecosystems
moral issues maintaining biodiversity
some think its wrong to stop humans from using resources that could boost their economy
- protecting one species could mean killing other species
ecological issues maintaining biodiversity
conservation schemes to protect one species could affect other species
political issues maintaining biodiversity
-some countries may not want to work together
-other countries may not want to sign an agreement
schemes may not be favoured in some communities - fishing restrictions in a fishing village
