CIE a level biology-Genetic
Technology Study Guide Questions
with Actual Answers 2025-2026
Updated.
What is the genetic code - Answer The genetic code is universal, its used by all organisms.
What are somatic cells? - Answer They're body cells and they have 46 chromosomes (23
pairs)
How many chromosomes do gametes have - Answer 23 chromosomes
What is recombinant DNA? - Answer The altered DNA formed when nucleotides from
different sources are lengthened
What is a transgenic organism? - Answer An organism that contains nucleotide sequences
from a different species
What is a genetically modified organism(GMO) - Answer An organism that has introduced
genetic material
Why is Recombinant DNA possible? - Answer It's because of the universal genetic code that
recombinant DNA is formed
What is genetic engineering? - Answer A technique used to deliberately modify a specific
characteristic of an organism. Techniques involve:
Removing a gene with the desired characteristics from one organism and transferring a
gene(using a vector) into another organism where the desired gene is the expressed. The
genetically engineered organism will then contain a recombinant DNA and become a GMO.
What steps must be taken for an organism to become genetically engineered - Answer 1-
Identification of the gene
2- Isolation of the desired gene by:cutting enzymes(restriction endonucleases), using reverse
transcriptase to make a single strand of the complementary DNA form mRNA and creating the
gene artificially using nucleotides.
3-Multiplication of the gene using polymerase chain reaction(PCR)
4- Transfer to the organism using a vector(Plasmids, viruses or liposomes)
5- Identification of the cells with the new gene by using a marker, which is then cloned.
, What is a marker? - Answer Markers are genes that code for identifiable substances that can
be tracked(e.g using GFP[green fluorescent protein] which fluorescent under UV light)
Ways in which the gene with specific characteristics that are required can be obtained - Answer
1- Extraction of genes(using restriction endonucleases)
2- mRNA and reverse transcriptase
3-Artificial Synthesis
Extraction of genes(using restriction endonucleases) - Answer 1-Restriction endonucleases
are a class of enzymes found in bacteria. They're used as a defence mechanism by bacteria
against bacteriophages
2-The enzymes restrict a viral infection by cutting the viral genetic material into smaller pieces
at specific nucleotide sequences within the molecule
3-Restriction endonucleases will separate the two strands of DNA at specific base sequences by
'cutting' the sugar-phosphate backbone in an uneven way to give sticky ends or straight across
to give blunt ends.
4-Sticky ends result in one strand of the DNA fragments sign longer than the other strand.
5-The sticky ends make it easier to insert the desired gene into another organisms DNA as they
can easily form hydrogen bonds with the complementary base sequences on other pieces of
DNA that have been cut with the same restriction enzyme.
6- when using genes isolated by restriction endonucleases that give blunt ends nucleotides can
be added to create sticky ends.
mRNA and Reverse transcriptase - Answer 1- Once isolated, the mRNA is then combined
with a reverse transcriptase enzyme and the nucleotides to create a single strand of
complementary DNA(cDNA).
2-Reverse Transcriptase enzymes are sourced from retroviruses and they catalyse the reaction
that reverses transcription. The mRNA is used as a template to make the cDNA.
3-DNA polymerase is then used to convert the single stranded cDNA into a double stranded
DNA molecule which contains the desired code for the gene.
Artificial synthesis - Answer 1-With the knowledge if the genetic code, scientists use
computers to generate the nucleotide sequence to produce the gene.
2- Short fragments of DNA are first produced which are joined to make longer sequences of
nucleotides and then inserted into vectors.
What is the function of DNA ligase - Answer Is used to splice(insert) the gene into the vector
Technology Study Guide Questions
with Actual Answers 2025-2026
Updated.
What is the genetic code - Answer The genetic code is universal, its used by all organisms.
What are somatic cells? - Answer They're body cells and they have 46 chromosomes (23
pairs)
How many chromosomes do gametes have - Answer 23 chromosomes
What is recombinant DNA? - Answer The altered DNA formed when nucleotides from
different sources are lengthened
What is a transgenic organism? - Answer An organism that contains nucleotide sequences
from a different species
What is a genetically modified organism(GMO) - Answer An organism that has introduced
genetic material
Why is Recombinant DNA possible? - Answer It's because of the universal genetic code that
recombinant DNA is formed
What is genetic engineering? - Answer A technique used to deliberately modify a specific
characteristic of an organism. Techniques involve:
Removing a gene with the desired characteristics from one organism and transferring a
gene(using a vector) into another organism where the desired gene is the expressed. The
genetically engineered organism will then contain a recombinant DNA and become a GMO.
What steps must be taken for an organism to become genetically engineered - Answer 1-
Identification of the gene
2- Isolation of the desired gene by:cutting enzymes(restriction endonucleases), using reverse
transcriptase to make a single strand of the complementary DNA form mRNA and creating the
gene artificially using nucleotides.
3-Multiplication of the gene using polymerase chain reaction(PCR)
4- Transfer to the organism using a vector(Plasmids, viruses or liposomes)
5- Identification of the cells with the new gene by using a marker, which is then cloned.
, What is a marker? - Answer Markers are genes that code for identifiable substances that can
be tracked(e.g using GFP[green fluorescent protein] which fluorescent under UV light)
Ways in which the gene with specific characteristics that are required can be obtained - Answer
1- Extraction of genes(using restriction endonucleases)
2- mRNA and reverse transcriptase
3-Artificial Synthesis
Extraction of genes(using restriction endonucleases) - Answer 1-Restriction endonucleases
are a class of enzymes found in bacteria. They're used as a defence mechanism by bacteria
against bacteriophages
2-The enzymes restrict a viral infection by cutting the viral genetic material into smaller pieces
at specific nucleotide sequences within the molecule
3-Restriction endonucleases will separate the two strands of DNA at specific base sequences by
'cutting' the sugar-phosphate backbone in an uneven way to give sticky ends or straight across
to give blunt ends.
4-Sticky ends result in one strand of the DNA fragments sign longer than the other strand.
5-The sticky ends make it easier to insert the desired gene into another organisms DNA as they
can easily form hydrogen bonds with the complementary base sequences on other pieces of
DNA that have been cut with the same restriction enzyme.
6- when using genes isolated by restriction endonucleases that give blunt ends nucleotides can
be added to create sticky ends.
mRNA and Reverse transcriptase - Answer 1- Once isolated, the mRNA is then combined
with a reverse transcriptase enzyme and the nucleotides to create a single strand of
complementary DNA(cDNA).
2-Reverse Transcriptase enzymes are sourced from retroviruses and they catalyse the reaction
that reverses transcription. The mRNA is used as a template to make the cDNA.
3-DNA polymerase is then used to convert the single stranded cDNA into a double stranded
DNA molecule which contains the desired code for the gene.
Artificial synthesis - Answer 1-With the knowledge if the genetic code, scientists use
computers to generate the nucleotide sequence to produce the gene.
2- Short fragments of DNA are first produced which are joined to make longer sequences of
nucleotides and then inserted into vectors.
What is the function of DNA ligase - Answer Is used to splice(insert) the gene into the vector
