Genetic information, variation and relationships between organisms Flashcards
Give three ways prokaryotic DNA differs from Eukaryotic DNA
Shorter
Not associated with proteins
circular
What proteins are DNA molecules in eukaryotes associated with
Histone proteins
Name two organelles of Eukaryotes which contain DNA
Mitochondria
Chloroplast
What two things do genes code for the production of
Amino acid sequence of a peptide
Functional RNA
Name the term for the position on a chromosome that a specific gene occupies
locus
What is meant by the term “Degenerate code”
several codons code for the same amino acid
What are the no-coding sections of DNA called
Introns
Name the four different bases in DNA
Gyannine
Cytosine
Adenine
Thymine
Which base is switched to Uracil in RNA
Thymine
Define Genome
The complete set of genes in a cell
Define Proteome
A full range of proteins a cell is able to produce
Define Allele
An alternative form of a gene
Two sister chromatids are joined at what
Centromere
The section of three bases in tRNA which binds to the mRNA strand is called
Anticodon
Give the three components of DNA
Deoxyribose 5 carbon sugar
Phosphate bacjbone
Nitrogen containing base
What is the difference in RNA
Ribose 5 carbon sugar
State the complementary base pairings in DNA and RNA
C-G, A-T. A-U in RNA
In what process is pre-mRNA created
Transcription
Which enzyme is involved in this process to join RNA nucleotides together
RNA Polymerase
What is the DNA strand known as in this process
Template strand
What happens to pre-mRNA before it leave the nuclear envelope
The introns are removed
When mRNA is in the cytoplasm, which organelle does it attach to for the next stage of protein synthesis
Ribosome
What bond forms between two amino acids in protein synthesis
Peptide bond
What is the role of ATP in translation
Provides energy for bond to form between tRNA and the amino acid
What is the role of tRNA in translation
Carries amino acids to the nucleotide. Lines them in correct order
What is a gene mutation
A change in the DNA base sequence of chromosomes
What difference often arises due to substitution mutations
A single different amino acid
Why do some substitution mutations not affect the protein function at all
Degenerate DNA. Several codons can code for same amino acid
In a deletion mutation, why is it unlikely that the polypeptide coded for will function correctly
Frame shift occurs
What is the process called in which mutations in the number of chromosomes occurs
Chromosome non disjunction
In sexual reproduction, what fuses to give rise to a new offspring
Gametes
What is a diploid number of chromosomes
Number of chromosomes. A diploid is two copies of each (2n)
How many chromosomes do humans have
46 (23 pairs)
Define homologous chromosomes
Pairs of matching chromosomes
In the first stage of meiosis, meiosis 1 what separates
The homologous pairs
What then separates in meiosis 2
Sister chromatids
name two processes which increase genetic variation int eh offspring which are a result of meiosis
Crossing over, independent segregation of chromosomes
outline the process which occurs in meiosis 1 which increases genetic variation
Crossing over. The chromatids wrap around each other and swap bits of genetic. information. This means each chromatid has the same genes but a different combination of alleles
How many haploid daughter cells are produced from one diploid parent cell
4
Define genetic diversity
The number of different alleles in a species / population
outline natural selection
Individuals with an allele that increases survival change are more likely to survive, reproduce and pass on their genes. This leads to an increase of allele frequency of beneficial genes, which over time leads to evolution
What causes bacteria to be resistant to antibiotics
Mutation in their DNA allows some bacteria to survive the use of antibiotics. This enables those bacteria to survive and reproduce, passing on the resistant alleles to their offspring
What type of selection is exemplified by antibiotic resistant bacteria
Directional selection
Why are human birth weights an example of stabilising selection
Babies at the extreme ends aren’t able to survive
Give an example of anatomical adaptation that can result from natural selection
Anatomical are physical features such as an animal’s shape
Give an example of Physiological adaptation that can result from natural selection
Include the ability to make venom but also more general functions such as temperature regulation
Give an example of behavioural adaptation that can result from natural selection
behavioural adaptations can be inherited r learnt and include tool use, language and swarming behaviour
Define species
a species is a group of similar organisms that can reproduce to produce fertile offspring
What parts of the classification system are used to name a species
Genus, Species
Starting with Domain, list the hierarchy of classification
DKPCOFGS Domain Kingdom Phylum Class Order Family Genus Species
Give two benefits to the species of courtship behaviour
Prevents mating with members of different species. Allows members of species to know when others are read to mate
What is species richness a measure of
The number of different species in a community
What does the index of diversity look at? How is it calculated
The number of species and the abundance of each species in a community
N(N-1)
d = —————————————–
weird sharp E shape n(n-1)
where d = diversity
N= total number of organisms of all species
n = total number of organisms of EACH species
How do farming techniques effect biodiversity
Reduce
Give three methods that can be done to help achieve a balance between food production and conservation
Plant hedges between fields instead of using fences.
Leaving margins around fields for wild flowers to grow.
Leave fields unplanted occasionally
Name three ways in which it is possible to measure genetic diversity within or between species
Genome sequencing
Comparing amino acid sequences
Immunological comparisons
What is the best way to eliminate sampling bias
Random sampling
