Eksamens spørsmål

Question 1

What is a microarray ?

Answer 1

Its a marker used for DNA expression analysis. Many probes are immobilised to solid support, samples are introduces in liquid phase.

It helps especially in the identification of single-nucleotide polymorphisms (SNPs) and mutations, classification of tumors, identification of target genes of tumor suppressors,

Microarrays are composed of hundreds to thousands of DNA probes bound to a solid surface to allow simultaneous detection of nucleic acid targets. Genes present or expressed in organisms can be detected after fluorescent labeling and hybridization to the corresponding probes on the microarray.

Question 2

How is the converstion from RNA to cDNA (RT-PCR)

Answer 2

cDNA Synthesis describes the generation of complementary DNA (cDNA) from an RNA template by reverse transcription. Reverse transcriptases (RTs) use an RNA template and a primer complementary to the RNA to direct the synthesis of the first strand cDNA, which can be used directly as a template for the Polymerase Chain Reaction (PCR). This combination of reverse transcription and PCR (RT-PCR) allows the detection of low abundance RNAs in a sample, and production of the corresponding cDNA, thereby facilitating the cloning of low copy genes.

Question 3

What is SANGER- sequencing?

Answer 3

• ddNTP is always used
• Hundreds of fragments with different lengths are produced in every reaction
• A complete sequencing can read up to 800 nukleotides.
• Has a high accuracy

Question 4

How is DNA cloning done?

Answer 4

In the classical restriction enzyme digestion and ligation cloning protocols, cloning of any DNA fragment essentially involves four steps:
Sequence isolation of the DNA of interest (or target DNA),
insert into vector, transfection bacteria(or transformation), and a culture bacteria / screening/selection procedure.

DNA cloning allows us to isolate a sequence of DNA (100-1,000,000 bp) and amplify it (clone it). This is done using BACs (Bacterial Artificial Chromosomes).

Question 5

What is a minimum tiling path?

Answer 5

An ordered list or map that defines the minimal set of overlapping clones needed to provide complete coverage of a chromosome or other extended segment of DNA.

Question 6

What is High-throughput Sequencing (HTS) and how does it work?

Answer 6

Question 7

What type of markers are there?

Answer 7

• SNP markers - -> Codomnant markers
• Kasp markers
  -SSR (Microsatelites)
  -AFLp
  -DArT

Question 8

What is a linkage map? What is needed to make a linckage map?

Answer 8

Linkage maps Show relative distances between markers along a chromosome

Based on markerdata from recombination. The markers close to each other show less recombination than markers far from each other.
We can use the recombination frequency between markers to determine their relative placement along the chromosomes.

Question 9

What is allopolyploydi?

Answer 9

Allopolyploidi er en kombinasjon av kromosomer fra to eller flere arter som gir opphav til en ny art.

Question 10

What is TILLING?

Question 11

Hva er GWAS?

Answer 11

Genome-wide association studies Is based on linkage differences with markers and genes that affect the trait.

Question 12

Hva gjør ett manhatten plot?

Answer 12

Its used to visualise significant markers on the chromosome in association mapping.

Question 13

Hva er QTL?

Answer 13

Quantitative trait locus –> QTL mapping in a population with offspring is usually based on linkage maps that show linkage between marker and gene to localize the genes affecting a quantitative trait.

 Less recombination between marker and gene – the closer the marker
 The statistical association between a marker and a gene depends on both distance and the effect the gene has on the phenotype

Question 14

What is a linkage map?

Answer 14

It gives the distance between different markeres based on recombination (cM)

Question 15

What is BAC?

Answer 15

Question 16

What is alternative spleising?

Answer 16

pre-mRNA from the same gene can make different mature mRNA by changing and rearranging the exones in different ways, and therefore give rise to different proteins. This can make multiple proteins from the same gene. Spleisingen styres av snRNP-molekyler som det fins flere av og et antall andre molekyler

Question 17

WHat is SINE and LINE? what function so they have ?

Answer 17

They are pseudogenes that are Non-functional DNA that resembles a gene Gene fragment . They can copy themself via RNA and be integrated on randome places in the genome. They can have destructeble function and sometimes contribute to new function.

Question 18

How will mutations be heritated ?

Answer 18

Mutations that destroy the gene products function will be inherited recessive, while mutations that change the gene product will often be inherited dominant ( miss sense mutation).

Question 19

What is a genetic marker

Answer 19

• A clear fenotype can be used as a genetic marker
• Microsatelittes and SNPs are used as genetic markers.
  -Genetic markers represent polymorf positions in the genome
• Genetic markers can be used to find relatives.

Question 20

What is Polymorfism?

Answer 20

betyr at en monogen egenskap finnes i to eller flere varianter i en befolkning.

Question 21

What is SNPs and microsatelites?

Answer 21

• Microsatelites usually have more allels than SNPs
• Microsatelites are ususaly found outside coding genes.
• SNPs can be in both coding and noncoding areas.
• There are more SNPs than microsatelites in the genome.

Question 22

What can you tell me about linkage and linkage differences (Ulikevekt)

Answer 22

Question 23

Embryonale stamceller

Answer 23

Question 24

What is transgressive segregation?

Answer 24

transgressive segregation is the formation of extreme phenotypes, or transgressive phenotypes, observed in segregated hybrid populations compared to phenotypes observed in the parental lines. The appearance of these transgressive (extreme) phenotypes can be either positive or negative in terms of fitness.