Modes of Inheritance
What does a colour circle depict on a pedigree?
Affected Female
What is an allele?
gene varient
What is a mutation?
change in genotype
What is a gene?
DNA sequence that is transcribed and translated i.e. codes for a protein
What are restriction endonucleases?
Why are they important?
cut DNA at a specific region – ensures the cut areas will match together again
We want compatible sticky ends for ligation to occur – without this it cannot be transformed
What is the mode of inheritance?
I have atleast 1 affected individual in each generation and males & females are affected equally.
Autosomal Dominant
What does homozygous and heterozygous mean?
Homozygous – an individual carrying two copies of the same allele for a given gene
Heterozygous – an individual carrying one copy each of two different alleles for a given gene
What is a small scale mutation?
Give an example
Occurs at gene or base pair level
Examples:
What are enhancers?
Control elements that are switched on during certain stages of development and control multiple genes. Can be up to 50Kbp away.
What are the three components of a plasmid vector?
Ori- Origin of replication (where DNA polymerase binds)
MCS – Multiple cloning site (contains area for DNA cutting)
Selectable marker - e.g. ampicillin resistance gene (which cells took up the plasmid so we can select for them)
If I have a flower that is presenting with red and white spots what is the mode of inheritance?
Co-Dominance
What is Mendel's First Law?
Independent Segregation – For any single gene, the alleles segregate independently, such that any gamete has an equally likely chance of inheriting either allele
What is a large scale mutation?
Give an example
Occur at chromosomal level
examples:
What is a karyotype? What are they used for?
What are the basic rules of PCR?
What are the four patterns of inheritance?
Explain each in simple terms
Pleiotropy - two traits always occur together (one gene, 2 traits)
Phenocopy - one genotype mimics another under specific environmental conditions
Multiple alleles - two or more alleles present for the same gene - more phenotypes observed (blood types)
Lethal alleles - one homozygous genotype is not viable
What is Mendel's Second Law?
Random Assortment – For any pair of genes, the alleles of one gene will sort into gametes independently of the second gene
What are the types of translocations?
Provide a brief explanation
Centric fusion (Robertsonian translocation)
Reciprocal translocation
What are the two states chromatin can be in? Describe them.
Relaxed (extended) = required for gene expression, usual state, not visible
Supercoiled (condensed) = no gene expression, during meiosis &mitosis, visible under microscope
What are the steps of cloning?
Explain
What is the difference between epistasis and dominance?
Dominance is interactions between two alleles at one gene
Epistasis is interactions between alleles at multiple genes
What does each line represent?
Line 1 - RR x rr
Line two - Rr
Line Three - Rr x Rr
Line Four - RR, Rr, R, rr
Grandparents (purebreds)
F1 Generation
Hybrid cross (F1xF1)
Offspring
A plant is discovered to have a mutation where one chromosome has undergone a reciprocal translocation. Predict and explain what effects this could have on:
a) Phenotype
b) Fertility
c) Evolution/speciation potential
a) Phenotype – Likely unaffected if the gene complement is complete, though gene regulation could be altered.
b) Fertility – Reduced due to misalignment of chromosomes during meiosis, leading to unbalanced gametes.
c) Evolution/speciation – If the mutation becomes fixed in a population, it could lead to reproductive isolation and contribute to the formation of a new species
What promoters are there and are they prokaryotic/eukaryotic?
Constitutive - both
Inducible - both
tissue & cell specific - eukaryote
What is required for PCR and what are the basic steps?
Components:
Denaturing
Annealing
Extension