Inheritance, Variation and Evolution 2 Flashcards
What is a mutation
A change in a base in DNA
How to name an organism using classification system (Binomial name)
Genus, Species
Who came up with the classification system
Linneaus
Binomial name meaning
Genus, Species
(How you determine the name of any organism as binomial means 2 names)
Linneaus used a classification system to group together living organisms based on what 2 things
Structure and characteristics
What advancement allowed Linneaus’s classification system to be replaced with the ‘Three Domain’ system
Technology
E.g microscopes, DNA evidence and biochemistry
Who developed the Three Domain system
Woese
Which system is used today, the classification system or the Three Domain system
Three Domain system
(It’s more advanced due to using technology e.g biochemistry)
3 categories Three Domain divides organisms into
Archaea
Bacteria
Eukaryota
What is included in the Archaea category in the Three Domain
Primitive (ancient) bacteria (live in extreme environments)
What comes under the ‘Bacteria’ category in the Three Domain
True bacteria
What comes under the Eukaryota category in the Three Domain
Animals
Plants
Protists
Fungi
Development of classification system to Three Domain system including how each system works and who came up with it
1) Linnaeus came up with the classification system: kingdom, phylum, class, order, family, genus, species
Organisms are categorised based on structure and characteristics
Organisms are named using the binomial system (genus, species) which is how you decide the name for each organism
2) Advances in technology led to Classification system being replaced with ‘Three Domain’ system which was developed by Woese
Organisms categorised into 3 categories: bacteria (true bacteria), archaea (primitive bacteria), eukaryota (plants, animals, fungi, protists)
Variation definition
Differences in characteristics between individuals in the same population
3 main causes of variation (differences in characteristics between individuals in the same population)
1) inheriting different genes e.g eye colour
2) Environment e.g language spoken
3) combination of both genes and environment e.g height can be based off genes and diet
True or false, most mutations have an effect on our phenotype
False
Most have no effect
Variation is caused by 3 things including genes, environment and combination of genes and environment
But what causes specifically genetic variation
Mutations
Very rarely a mutation leads to a new what
Phenotype
(But most of the time mutations have no effect on phenotype)
When is a mutation leading to a new phenotype an advantage (although it’s very rare that mutations actually change the phenotype)
If the environment changes
Then the new phenotype can actually be beneficial
This then leads to rapid change in a species
What does it lead to if a mutation leads to a new phenotype that can be beneficial if the environment changes
Rapid change in that species
Describe process of natural selection
1) Variation in phenotypes occur between different organisms of the same species (e.g some rabbits have thick fur, some rabbits have thin fur)
2) if the environment changes, organisms best suited to the environment are more likely to survive and reproduce (e.g if it suddenly got colder the rabbits with thick fur would be more likely to survive)
3) These beneficial characteristics are passed on to the offspring e.g thick fur
(This happens over many generations until the beneficial characteristics are widespread across the population meaning that the species has evolved)
Evolution occurs through what process
Natural selection
Evolution meaning
Change in inherited characteristics of a population overtime through the process of natural selection
4 key examples of selective breeding
1) domestic dogs have been selectively bred to have a gentle nature
2) food crops have been selectively bred to be resistant to disease
3) Animals e.g cows have been selectively bred to produce more meat and milk
4) Certain plants have been selectively bred to produce large or unusual flowers