week 1

Question 1

how many chromosomes do we have? How are they diveded?

Answer 1

23 pairs of chromosomes
22 pairs of autosomes
1 pair of sexchromosomes

Question 2

chromosomes consist of DNA, which is winded around ….. to fit in the cell’s nucleus

Answer 2

histones

Question 3

DNA constis of …. group and has which four bases? these bases attatch to each other.

Answer 3

• sugar-phosphate
  1. adenine (A)
  2. Thymine (T)
  3. Guanine (G)
  4. Cystosine (C)

Question 4

Gene encode for protein and are the building blocks of your body. In which two steps are genes generated to protein?

Answer 4

1. DNA–>mRNA
2. mRNA–>protein

Question 5

1% of the human genes different within the species. one of them is mutation.

• what are mutations?
• what are the consequences on protein?

Answer 5

mutations cause permanent change in DNA. When DNA is not repaired, it can lead to changes in protein.

Question 6

1% of the human genes different within the species. one of them is polymorphisms

What are they? use VNTR’s and SNP’s
How does it differ from a mutation?

Answer 6

• multiple frequent variants of gene in population.
• VNTR’s= verschil in meerdere sequenties van DNA
• SNP’s=verschil in een enkele nucleotide in het DNA

Mutations are more rare.

Question 7

some genes are Mendelian inhertance

what does this mean?

Answer 7

Dominant or Recessive

the BB, bB story.

Question 8

protein production is dynamic & continuously influenced by various factors. like epistasis and epigenetics.

define epistasis and give an example

Answer 8

• epistasis= allele at one locus interferes or masks an allele at another locus.

EG: it doesn’t matter if you have genes for blond or red hair if you have a bald gene. the bald (allele at one locus) masks the hair color (allele at another locus)

Question 9

protein production is dynamic & continuously influenced by various factors. like epistasis and epigenetics.

define epigenetics give an example and name some factors

Answer 9

epigenetics Epigenetics refers to changes in gene expression that don’t involve alterations to the underlying DNA sequence. These changes can affect how genes are turned on or off and are influenced by various factors, including environmental cues, lifestyle, and experiences.

EG: cool dudes hot chicks in crodile species. Where when it is colder the crocidele DNA within the eggs will create male crodiles.

other examples of factors are:
* diet
* light

Question 10

how do environmental factors regulate genes in epigenetics?

Answer 10

environmental factor (diet)
–>
factor activates or represses gene
–>
binding of the factor to DNA or histone alters the extent to which genes are available in the DNA to be activated

Question 11

what is an allergy?

Answer 11

hypersensitivity of immune system. considered a classic psychosomatic disorder. It is an interaction between genes and environment.

Question 12

Allergies are more common in the western world. How does the hygiene hypothesis explain this?

Answer 12

better hygiene in western countries leads to under stimulated imune system so it is reacting to substances that aren’t dangerous.

Question 13

what is meant with the heritabillity gap?

Answer 13

twin studies seem to overestimate genetic components (because twins also share environment).

Question 14

What is the relationship between serotonin-transporter (5-HTTLPR)and stressful life events and major depression disorder?

Answer 14

long allele (parent 1) + long allele (parent 2) of ST (polymorfism) x stressfull life events = low to no chance of MDD

short allele (parent 1) + long allele (parent 2) of ST (polymorfism) x stressfull life events = medium chance of MDD

short allele (parent 1) + short allele (parent 2) of ST (polymorfism) x stressfull life events = high chance of MDD

Question 15

findings from candate gene association studies are not always replicated by GWAS.

name 5 reasons for this?

Answer 15

• small sample size
• multiple genes play role (polygenic)
• environmental factors
• biological hypothesis difficult to formulate
• differential susceptibility averages out the impact of genes.

Question 16

one reason why findings from candate gene association studies are not always replicated by GWAS is: differential susceptibility averages out the impact of genes.

explain this concept.

Answer 16

the variability of genetic effects in different environments or populations (differential susceptibility) can lead to inconsistencies between candidate gene studies and GWAS findings. Candidate gene studies might identify a gene as significant under specific conditions or in a specific population, but when examined across a broader, more diverse group in a GWAS, the average effect of that gene might be too small or inconsistent to be detected.

Question 17

one study claimes that the COMT-gene x active cannabis use during adolescence, doubles or tripples the risk of schizophrenia.

what does this show?

Answer 17

a defficiency in dopamine systems plays an important role in schizophrenia.

Question 18

knowing genetics play an important role in the expression of a clinical application. In which two ways can we peronalize medicine?

Answer 18

• pharmacogenomics: genotype-guided drug treatment.
• change the biological products of DNA by epigenetic therapy. So change the enironmental factors (diet, less stress, stop smoking, etc)

Question 19

What is Crispr-CAS9?

Answer 19

CRISPR-Cas9 is a revolutionary technology that has transformed the field of genetic engineering. It allows for precise, directed changes to genomic DNA.

Question 20

in which three ways can we apply Crispr-CAS9?

Answer 20

1. replicate genetic basis–>research
2. gene therapy: restoring, changing a gene.
3. disease prevention: editing reproductive cells.

Question 21

at this stage mingeling with DNA with CAS9, safety is a concern. What are three risks?

Answer 21

1. triggering immume response
2. mixture of healthy and diseased cells
3. off-target mutations (harming vital genes)