nov13th

Question 1

Excitotoxicity in stroke

Answer 1

Excitotoxicity is caused by extracellular glutamate accumulation leading to uncontrolled ion influx into neurons.

Question 2

Neo-antigens in cancer

Answer 2

Neo-antigens are tumor-specific antigens arising from mutations and are targeted by immune checkpoint therapy.

Question 3

PSI-BLAST profile

Answer 3

A profile in PSI-BLAST is made from a multiple alignment highlighting conservation at each position.

Question 4

Cerebral organoids limitations

Answer 4

Human cerebral organoids are not suitable for studying sensory pain mechanisms.

Question 5

Stem cell potency

Answer 5

Multipotent stem cells have higher differentiation capacity than oligopotent stem cells.

Question 6

Inflammation in stroke

Answer 6

Inflammation after a stroke often exacerbates damage rather than promoting repair.

Question 7

FASTA format

Answer 7

A FASTA file starts with ‘>’ followed by an identifier, with sequence data on subsequent lines.

Question 8

Positive positions in BLAST

Answer 8

Positive positions refer to identical matches or conservative substitutions with a positive score.

Question 9

Cancer heterogeneity

Answer 9

Most tumors are genetically heterogeneous with treatment-resistant subclones.

Question 10

Telomerase activity

Answer 10

Telomerase adds repetitive sequences to chromosome ends, preventing shortening during replication.

Question 11

Lynch syndrome

Answer 11

Lynch syndrome is caused by inherited MMR gene mutations, increasing cancer risk.

Question 12

Trans-differentiation

Answer 12

Trans-differentiation converts one differentiated cell type directly into another.

Question 13

Random mutations in cancer

Answer 13

Random mutations during DNA replication are a major contributor to cancer risk in high turnover tissues.

Question 14

Organoids for neurodevelopment

Answer 14

Cerebral organoids are suitable for studying human neurodevelopment and neurological diseases.

Question 15

ROS in stroke

Answer 15

Reactive oxygen species (ROS) accumulation causes cellular injury and neuronal death in ischemic stroke.

Question 16

Checkpoint inhibitors

Answer 16

Immune checkpoint inhibitors block PD-1 or CTLA-4, restoring immune response against tumors.

Question 17

Excitotoxicity mechanism

Answer 17

Overactivation of NMDA and AMPA receptors by glutamate leads to calcium influx and cell death.

Question 18

Mismatch repair genes

Answer 18

MLH1, MSH2, MSH6, and PMS2 mutations are linked to Lynch syndrome.

Question 19

PSI-BLAST iterations

Answer 19

PSI-BLAST refines searches iteratively using a position-specific scoring matrix (PSSM).

Question 20

Profiles in PSI-BLAST

Answer 20

Profiles enhance sensitivity by highlighting conserved sequence features in multiple alignments.

Question 21

Pluripotent vs multipotent

Answer 21

Pluripotent stem cells can differentiate into all body cell types except extra-embryonic tissues.

Question 22

Multipotent stem cell examples

Answer 22

Multipotent stem cells include hematopoietic and mesenchymal stem cells.

Question 23

Stem cell differentiation

Answer 23

Stem cell potency decreases from totipotent to pluripotent, multipotent, and oligopotent.

Question 24

Sporadic vs hereditary cancer

Answer 24

Sporadic cancers arise from random mutations, while hereditary cancers involve germline mutations.

Question 25

Neo-antigen definition

Answer 25

Neo-antigens are newly formed antigens resulting from somatic mutations in tumors.

Question 26

False-negative PCR causes

Answer 26

Mismatched primers or low target DNA concentration can cause false-negative PCR results.

Question 27

RNA modifications

Answer 27

tRNA modifications include methylation and pseudouridylation for stability and function.

Question 28

Telomerase in cancer

Answer 28

Telomerase activation in cancer cells allows indefinite proliferation by maintaining telomere length.

Question 29

CFTR compound heterozygosity

Answer 29

Compound heterozygosity involves two different CFTR mutations causing cystic fibrosis.

Question 30

Heterozygous genotype calculation

Answer 30

For alleles with frequencies p and q, the heterozygous frequency is calculated as 2pq.

Question 31

Immune tolerance

Answer 31

Immune tolerance prevents the immune system from attacking self-antigens.