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
Describe the process of selective breeding
1) select parents with the desired characteristic from a mixed population
2) Breed them together
3) Choose offspring with desirable characteristic and breed them together
4) repeat this over many generations until all offspring have desired characteristic
Fill in the gaps for key examples of selective breeding
1) domestic dogs are selectively bred to have a … nature
2) Animals e.g cows are selectively bred to produce more… and …
3) certain flowers are selectively bred to have…..or…..flowers
4) crops are selectively bred to be resistant to….
Gentle
Meat, milk
Large, unusual
Diseases
2 key problem of selective breeding
Inbreeding (breeding together closely related animals/ plants)
Causes some breeds to be particularly prone to inherited diseases/ defects
Reduces genetic variation (all of a species could be susceptible to a certain disease)
One key problem of selective breeding is inbreeding which is where…
This is bad because it can make some breeds particularly prone to…
Closely related plants/ animals are bred together
Inherited diseases/ defects
Variation is the differences in characteristics between individuals of the same…
Population
Variation is the change in ….. of a……. overtime through the process of natural selection
Inherited Characteristics
Population
What is genetic engineering
The genome of an organism is changed by introducing a new gene from another organism in order to produce a desired characteristic
Genetic engineering is where the…. of an organism is changed by introducing a… from another organism to produce a desired….
Genome
Gene
Characteristic
Another word for genetic engineering (how it is advertised in food)
Genetic modification
2 key examples of where genetic engineering is used
Crops
(to get GM crops- crops can produce bigger/ better fruits, be resistant to certain diseases, produce a higher yield etc)
To treat type 1 diabetes (bacteria contain insulin gene to produce insulin)
How is insulin produced through genetic engineering
Bacteria given human insulin gene
Bacteria produce insulin
Insulin purified and used (e.g for people with type 1 diabetes to inject insulin into themselves)
Process of genetic engineering (changing the genome of an organism by introducing a gene from another organism to produce a desired characteristic e.g larger crop yield)
1) identify gene we want to transfer
2) enzymes used to isolate gene
3) gene transferred into vector e.g plasmid
4) desired gene inserted into cells of target organism during early stage of organism development
Process of genetic engineering:
1) identify… that we want
2) use… to isolate the gene
3) transfer gene into….e.g plasmid
4) insert desired gene into cells of targeted organism using the vector
Important- this must be done during organism’s early stage of..
Gene
Enzymes
Vector
Development
How cuttings makes clone of plant
Remove small piece of plant
Dip end of plant in rooting powder
Let plant grow as normal
Which method of plant cloning is very easy and gardeners have used for many years
Cuttings
For cuttings (type of plant cloning) what must you dip the end of the plant in to help it grow
Rooting powder
Which type of plant cloning only produces a few clones of the plant
Cuttings
(Tissue cultures produce lots more so are used commercially)
2 methods of plant cloning
Tissue culture
Cuttings
Method of tissue culture for plant cloning
1) Take plant we want to clone
2) divide plant into hundreds of tiny pieces (each piece contains a small number of cells)
3) incubate plant cells with plant hormones to allow plants to grow into full sized clones
Tissue cultures help preserve….species of plant
Rare
Which method of plant cloning helps preserve rare species of plant
Tissue culture
Which method of plant cloning is done on a large scale, helps preserve rare plant species and is quick and cheap
Tissue cultures
2 methods of cloning in animals
Adult cells cloning
Embryo transplant
Embryo transplant method (type of animal cloning)
Split cells apart from an early developing embryo before they have become specialised
Transplant identical embryos into host mothers
In embryo transplants… are split apart from an early developing…before they have become…and are then transplanted into host mothers
Cells
Embryo
Specialised
Process of adult cell cloning
1) Body cell taken from animal (sheep 1) we want to clone and nucleus is removed
2) take egg cell from another animal (sheep 2) and remove nucleus
3) nucleus from sheep 1 inserted into egg cell of sheep 2 and given an electric shock to stimulate it to divide and develop into an embryo
5) embryo inserted (transplanted) into uterus of sheep 3 which gives birth to a clone of sheep 1
In adult cell cloning What stimulates the egg cell with the nucleus inserted in it to divide into an embryo
Electric shock
Darwin developed the theory of…by
Evolution
Natural selection
In 1859 Darwin published a book called what
On the Origin of species
Darwin published a book called ‘on the origin of species’ in what year
1859
In what year did Darwin publish his book on his theory of evolution by natural selection and what was it called
1859
On the origin of species
In 1859 Darwin published his book called ‘on the origin of species’ based on his theory of what
Evolution by natural selection
True or false, Darwin’s theory of evolution by natural selection was immediately accepted
False
It was only gradually accepted
Was Darwin’s theory of evolution by natural selection controversial or not
Yes
It was extremely controversial
4 reasons Why Darwin’s theory of evolution by natural selection was extremely controversial so only gradually accepted
1) it challenged the idea that God made all of Earth’s plants and animals
2) lack of evidence (at the time the theory was published)
3) genetics was not understood
4) theories by other scientists e.g Lamarck
Religious reason why Darwin’s theory of evolution by natural selection was not initially accepted
Challenged idea that God made all of Earth’s plants and animals
One key other person who had a theory at the same time as Darwin’s
Lamarck
But his theory has now been proven incorrect
Which person looked at the theory of evolution by natural selection at the same time as Darwin
Wallace
(Lamarck also had a theory of evolution but it wasn’t based off natural selection)
Wallace was specifically interested in..in animals
Warning colourations
What is speciation
The gradual formation of a new species due to evolution
Describe speciation (process of how new species form)
1) 2 populations of one species are isolated from each other by a geographical barrier e.g by a river
2) natural selection occurs for the 2 different populations so over many generations the 2 populations change in different ways due to different beneficial characteristics being passed down
3) eventually the phenotypes of the 2 different populations are so different that they cannot successfully breed to produce fertile offspring
4) now the 2 different populations are classed as 2 different species
In order for speciation to occur, first 2 populations of a species must be separated by a…. e.g River/ mountain range
Geographical barrier
In speciation, what key process occurs within each of the populations of the separated species (e.g snails on one side of the river and snails on the other side of the river)
Natural selection
E.g One population of snails may get bigger
One population of snails may get smaller
Mendel carried out experiments in the 1800s on…plants
Pea
From his experiments in pea plants in the 1800s Mendel found that the characteristics are determined by…and these don’t change when passed onto the offspring
Inherited units
(Now called genes)
What did Mendel find from his experiments on pea plants (2 key things)
Characteristics are determined by inherited units (now called genes)
These inherited units (genes) can be recessive or dominant
Who discovered that genes can be dominant or recessive
Mendel
True or false, most scientists agreed with Mendel’s findings (Inherited units (Genes) determine characteristics and genes can be either dominant or recessive)
False
Many scientists still believed in blended inheritance
Instead of agreeing with what Mendel found, what did most scientists at the time still believe in
Blended inheritance (.g a white flower and a purple flower produce a lilac flower)
3 key stages in development of gene theory (after Mendel’s work on pea plants in the 1800s)
1) late 1800s- behaviour of chromosomes during cell division is observed
2) early 1900s idea that genes are located in chromosomes as they both behave similarly
3) mid 1900s structure of DNA and how genes function was determined
1st key stage in development of the gene theory (not to do with Mendel) was in the late 1800s where the behaviour of….during…was observed
Chromosomes
Cell division
In the mid 1900s as the last key stage in the gene theory scientists determined the structure of….and the function of…
DNA
Genes
The second key stage in the gene theory was in the early 1900s and was that genes and chromosomes behave similarly which means that…
Genes are located in chromosomes
What are fossils
The remains of living organisms that dies millions of years ago which are found in rocks
What are fossils
The remains of livings organisms from millions of years ago which are found in rocks
Fossils are the remains of….. from…… of years ago which are found in…..
Living organisms
Millions
Rocks
3 key ways fossils can form (remains of living organisms from millions of years ago which are found in rocks)
1) from parts of organisms that haven’t decayed (conditions needed for decay are absent e.g it’s too cold/ lack of oxygen/ lack of water)
2) the organism has decayed but parts of the organism are slowly replaced by minerals during decay
3) persevered traces of organisms e.g burrows/ footprints
One way fossils can form is when the organism decays but parts of it are replaced with….
Minerals
One way fossils form is by the preservation of……of organisms e.g………
Traces
Footprints/ burrows
True or false, soft bodied organisms always form fossils
False
Soft bodied organisms very rarely formed fossils and many early organisms were soft bodied
(This is a big problem in the fossil record)
2 key problems with the fossil record
1) many early organisms were soft bodied so didn’t form fossils (most decayed before they could form fossils)
2) many fossils formed have been destroyed by geological or human activity- scientists cannot be certain of how life began on earth
One key problem with the fossil record is that many fossils have been destroyed by …..or……activity
Human
Geological
One key problem with the fossil record is that many fossils have been destroyed by human or geological activity which means that scientists cannot be certain about how….
Life began on Earth
What is extinction
Permanent loss of all members of a species
Why can bacteria evolve so quickly
Because they can reproduce at such a fast rate
Name for one common strain of antibiotic resistant bacteria
MRSA
Describe process of antibiotic resistance (how bacteria become resistant to antibiotics)
1) In a population of bacteria, genetic variation may occur due to mutations so some bacteria are resistant to the antibiotic
2) when the antibiotic is used to treat the disease only the resistant bacteria survive whilst all the non resistant bacteria are killed
3) the resistant bacteria quickly reproduce because they cannot be killed by the antibiotic so now all of the existing bacteria in the population are resistant to the antibiotic
3 ways to reduce the rise of antibiotic resistant strains
1) doctors only prescribe antibiotics when extremely necessary
2) patients must complete their full course of antibiotics (e.g every day for a week) to ensure all bacteria are killed so none can survive to mutate and form resistant strains
3) restrict use of antibiotics in farming
In selective breeding you take parents with the desired characteristic from a….population
Mixed
(E.g if you want large cows you take the parents from a population that includes big and small cows)
