B5 Flashcards
What is a genome ?
The entire genetic material of an organisim
Where is genetic material stored ?
In the chromosones which are in the nucleus
What is a gene ?
A short length of a chromosone
What is a allele ?
A different version of a gene
What is a genotype
All of the genes & alleles that an organism has
What is a phenotype ?
The charectristic that it displays i.e. blue eyes
What is continous variation ?
When indviduals in a population vary within a range - no distinct categoried i.e. height
What is discontinous variation ?
When there are 2 or more distinct categories- each indviduals only falls into one i.e. blood group
What is a mutation ?
A rare random change in an organisims DNA that can be inherited
What is meiosis ?
A type of cell division which doesn’t produce identical cells
What is a gamete
They only contain half the number of chromosones of normal cells - they are haploid
What is sexual reproduction ?
Where genetic information from 2 organisms is combined to produce offspring which are genetically different to the parents
What is asexual reproduction ?
- Where there is only 1 parent so the offspring are genetically identical to the parent
- It happens by mitosis
- The new cell has exactly the same genetic information as the parent cell
What does diploid mean ?
Having the full amount of chromosones - normal cells
What is meant by hapliod ?
Have half the amount of chromosones of a normal cell
What is a dominant allele
The version of charectristic that is shown
- alwyas a capital letter
What is a recessive allele
It only appears of there are 2 recessive alleles - non are dominant
- always written in lower case
What is homozygous
When 2 alleles for a trait are the same i.e.CC or cc
What is hetrozygous
2 different alleles for one trait i.e.Cc
What does variation occur between ?
Between species & within species
What causes variation ?
Genetics - which alleles have been inherited i.e. tounge rolling
Enviroment - Caused by a factor during your lifetime i.e scars or piercings
Who came up with ideas about natural selection and evolution ?
Darwin and Wallace
What ideas did Charles Darwin present ?
- The theory of evolution of species by natural selection
- Changes over time due to natural selection
- Natural selection is known as survivial of the fittest
What is the 5 step process of natural selection ?
- Random variation leads to mutation
- Competition - Some of te feature fit better with the enviroment of others
- Survival of the fittest- Those with the best allele will live longer enough to reproduce and pass on the allele
- Over time more indviduals in the population have this advantageous allele.
- This will continue until the enviroment changes
What is the peppered moth study ?
Moths with white wings were camoflaged on trees so lived longer.
Moths with black wings were easy for predatord to spot so they got killed
In the industrial revolution tree trunks were dicoloured by polloution
Now the black moths had an advantage so lived longer
So more moths became black winged
What does the fossil recors show us ?
It shows us how organisims that lived in the past differ from those today. It also shows how long a species existed for, by when it eneters & leaves the fossil record
What are the reasons for classification ?
- Easier to study
- Helps recognise bio-diversity
- Gives scientists common language
What are the 7 ways in which animals are classified ?
Kingdom
Phylum
Class
Order
Family
Genus
Species
Who created this hierarchial system ?
Carl Linnaeus - 1707-1778
What is the binomial name made up of ?
Genus + species
What is phylogenetics ?
The name given to the study of evolutinary relationships between species
How does bacteria become anti-biotic resistant ?
- A population of bacteria occurs
- A mutation occurs
- One or more bacteria in the population are anti-biotic resistant
- A bacterium with the resistant gene survives
- A whole population of the bacterium is now resistant to anti-biotics
