PCBl 3023l Examl 2l Latestl 2026l 2027l

PCBl 3023l Examl 2l (Latestl 2026/l 2027l Update)l Guide|l 100%l Verifiedl Questionsl &l Answersl |l Gradel A

Q:l Whatl isl directl reversal?

Answer:

-fixesl thel alteredl moleculel byl reversingl thel chemicall transformation -requiresl specificl enzymesl forl eachl individuall lesion

Q:l Directl reversal:l Somel organismsl canl reversel thyminel dimersl byl usingl al specificl _____

Answer:

photoreactivatingl enzyme

Q:l Basel excisionl repairl isl al ______l ______l forl repairingl nucleotidel mismatchesl causedl spontaneousl mutations.

Answer:

generall mechanism

Q:l Withl basel excisionl repair,l thel _____l ______l isl notl reversed.

Answer:

chemicall transformation

Q:l Whatl isl replacedl withl basel excisionl repair?

Answer: 1 / 4

Thel damagedl bases

Q:l Withl basel excisionl repair,l thel ______l ____l isl recognizedl andl replacedl beforel DNAl replicationl occurs.

Answer:

unpairedl base

Q:l Basel excisionl repairl (STEPl 1)

Answer:

DNAl glycosylasel removesl thel damagedl base,l anl endonucleasel recognizesl thel sitel andl cleavesl thel phosphodiesterl bond,l andl al deoxyribosephopshodiesterasel remainingl sugarl andl phosphate

Q:l Basel excisionl repairl (STEPl 2)

Answer:

DNAl polymerasel placesl al newl nucleotide

Q:l Basel excisionl repairl (STEPl 3)

Answer:

DNAl ligasel sealsl thel nick

Q:l Basel excisionl repair

Answer: 2 / 4

Q:l DNAl rearrangementsl are?

Answer:

Recombinationl eventsl thatl alterl thel arrangementsl ofl genesl withinl chromosomes.

Q:l Whatl isl site-specificl recombination?

Answer:

Itl occursl betweenl specificl DNAl sequencesl thatl sharel partiall sequencel homology.

Q:l Howl doesl site-specificl recombinationl differl froml homologousl crossingl over? 3 / 4

Answer:

Itl doesl notl dependl onl basel pairl recognitionl ofl homologousl sequencesl betweenl pairedl homologousl chromosomes;l instead,l specificl proteinsl recognizel homologousl sequencesl andl mediatel recombination.

Q:l Hematopoeisisl refersl to

Answer:

formationl ofl bloodl cells

Q:l Thel productionl ofl immunoglobulinsl occursl inl _____l ________l asl theyl differentiatel andl mature.

Answer:

Bl lymphocytes

Q:l Antibodiesl havel twol _____l chainsl andl twol ______l chains.

Answer:

heavy,l light

Q:l Thel heavyl andl lightl chainsl arel joinedl by?

Answer:

Disulfidel bondsl tol producel thel antibodyl shape.

Q:l Alll chainsl consistl ofl a?

Answer:

Variablel Nl regionl andl constantl Cl region

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