Genetic Information, Protein Synthesis, Classification & Biodiversity (SR) Flashcards
What is the difference between Prokaryotic and Eukaryotic DNA?
Prok DNA molecules are short, circular and not associated with proteins
Eukaryotic DNA found in nucleus. DNA very long, linear. DNA and associated proteins form a chromosome
What else contains DNA in Eukaryotic Cells?
Mitochondria and Chloroplasts
DNA similar to Proks as is short, circular and not associated with protein
What is the Genome?
Full set of DNA found in an organism
What is the Proteome?
Full range of Proteins that is or can be synthesised from the Genome
What is a gene?
Section of DNA that codes for polypeptides and functional RNA
Located at a fixed locus on a DNA molecule
What is a codon?
Sequence of 3 DNA bases
Codes for a specific amino acid
What features does the genetic code have?
Universal
Non-overlapping
Degenerate (e.g. alterations in codon can still code for same Amino Acid)
What is the term for sections of non-coding DNA in Eukaryotes?
Introns
What is the term for sections of DNA that codes for polypeptides in Eukaryotes?
Exons
What is Biodiversity?
Variety of Organisms in an area.
Can be considered on a local or global scale
What is Species Richness?
A Measure of the number of different species in a community
What is an Index of Diversity?
Measure of Biodiversity, taking into account species richness and number of individuals in each species
What is the equation for Index of Diversity?
Index of Diversity = (N(N-1)) ÷ (Σn(n-1))
N = total number of organisms of all species
n = total number of organisms of each species
How can Farming Techniques reduce biodiversity?
Monoculture (growing one type/species of plant), Use of Herbicides & Pesticides, Hedgerow removal and Woodland Clearance
How can Conservationists protect Biodiversity?
Using methods such as: Giving endangered species legal protection
Creating Protected Areas and,
The Environmental Stewardship Scheme
What is required between conservation and agri?
A balance of them both
How can Genetic Diversity within or between species be compared?
By looking at: Frequency of measurable/observable characteristics Base Sequence of DNA Base Sequence of mRNA Amino Acid Sequence of Proteins
What is Variation caused by?
Genetic and Environmental Factors
How can Variation be measured quantitatively within a species within a species?
1) Collecting Random Sample (to reduce bias)
2) Calculating a Mean value and the Standard Deviation of the data collected
3) Interpreting mean values and their standard deviations
What does varying Means show when measuring Variation?
Shows Variation between populations
What does a Large Standard Deviations indicate when measuring Variation?
Indicates a Large Amount of Variation within a Population
How can Genetic Variations arise?
Due to Mutation
What are Gene Mutations?
Changes to the base sequence of the base sequence or quantity of DNA within a Gene or Section of DNA
What are the three types (for AS) of Gene Mutation?
1) Substitution – Nucleotide changed to different nucleotide
2) Insertion – Addition of one or more nucleotides
3) Deletion – Removal of one or more nucleotides
What are Mutagenic Agents?
Physical or Chemical Agent that can alter the DAN or increase Rate of Gene Mutation
What are Chromosome Mutations?
Changes to the structure or number of whole Chromosomes.
E.g. failure of Chromosomes to separate in Meiosis (non-disjunction)
What else is a cause of Genetic Variation?
Meiosis:
Produces 4 daughter cells that are genetically different from each other
What happens in Meiosis 1?
Homologous Chromosomes are separated from each one
One Chromatid from each pair of Chromosomes go into one of the daughter cells
What occurs in Meiosis 2?
Sister Chromatids from each Chromosome are separated to form two more daughter cells
How does Variation occur during Meiosis?
Results from Independent Assortment of Chromosomes and Crossing over in Meiosis 1.
Random Fertilisation of Haploid Gametes as well
What are Alleles?
Different forms of the same gene
What is Genetic Diversity?
Number of different alleles of genes in a population
What can Genetic Diversity enable?
Enables Natural Selection to Occur
What is Natural Selection?
Mechanism of Evolution by which individuals better adapted to environment tend to survive and reproduce successfully and pass on their alleles