Genetic Engineering

Correct answer: A. Because it cuts DNA at the correct recognition site

The correct restriction enzyme makes a cut at the correct site. This helps join the gene and vector properly.

Correct answer: A. To separate the useful product from other substances

Many substances are produced in a host cell, so the desired product must be separated. Purification is especially important in medicine production.

Correct answer: A. Remember cut join carry select and check in order

Restriction enzyme cuts, ligase joins, vector carries, and selection shows correct cells. This order gives easy exam revision.

Correct answer: C. DNA segment carrying hereditary information

A gene is a DNA segment that carries information for a trait. For exams consider it the functional unit of heredity.

Correct answer: D. They can carry genes like vectors

Plasmids are small DNA molecules that can carry foreign genes. For exams remember plasmid as a common vector.

Correct answer: B. Cutting DNA at specific sites

Restriction enzymes cut DNA at specific recognition sites. For exams remember them as molecular scissors.

Correct answer: A. A molecule that carries a foreign gene into a host cell

A vector helps deliver a foreign gene into a host. Plasmids and viruses are examples of vectors in exams.

Correct answer: A. To multiply or express the foreign gene

A host cell can replicate and express recombinant DNA. For exams think of it as the workshop for the gene.

Correct answer: B. Uptake of external DNA by a cell

In transformation a cell takes up external DNA. For exams connect it with gene entry into a cell.

Correct answer: A. To identify successfully modified cells

A selectable marker helps select transformed cells. Antibiotic resistance gene is a common exam example.

Correct answer: A. To make many copies of a specific DNA segment

PCR makes many copies of a selected DNA segment. For exams remember it as a DNA amplification technique.

Correct answer: B. On the basis of size

Gel electrophoresis separates DNA fragments by size. For exams remember smaller fragments move faster.

Correct answer: A. A specific complementary DNA sequence

A DNA probe identifies target DNA by binding to a complementary sequence. For exams remember the rule of complementarity.

Correct answer: B. Separate small DNA in cytoplasm

In bacteria plasmid is usually small circular DNA in cytoplasm. For exams remember it as separate from the chromosome.

Correct answer: A. It is the site where foreign DNA can be inserted

A cloning site is the place in a vector where a foreign gene is inserted. For exams remember it as an insertion site.

Correct answer: A. A gene introduced from outside the host

A foreign gene is a gene introduced into the host from outside. In exams it may also be called the desired gene.

Correct answer: A. Human insulin

Human insulin has been produced using recombinant DNA technology. For exams remember it as a key example of medical biotechnology.

Correct answer: B. GMO

An organism whose genes are artificially modified is called a GMO. For exams remember its full form as genetically modified organism.

Correct answer: A. Insect resistance

Bt cotton has been given insect resistance. For exams remember it as an example of agricultural biotechnology.

Correct answer: A. It can transfer genes into plants

Agrobacterium is a natural tool for transferring genes into plants. For exams connect it with plant gene transfer.

Correct answer: A. Gene editing

The CRISPR-Cas system recognizes a specific DNA sequence and enables targeted changes in it; therefore, it is commonly used for gene editing. Measuring soil moisture is the function of an agricultural sensor, not CRISPR. Exam tip: associate CRISPR with targeted DNA modification and gene editing.

Correct answer: A. Compatible ends are produced in both

The same restriction enzyme creates compatible ends that are easier to join. For exams connect this with sticky ends.

Correct answer: A. Joining DNA fragments

Sticky ends help DNA fragments join through complementary bases. For exams remember them as useful for recombination.

Correct answer: A. Straight cut across both DNA strands

Blunt ends form when both strands are cut at the same position. For exams distinguish them from sticky ends.

Correct answer: A. Ligation

In ligation the gene is joined to the vector using DNA ligase. For exams remember it as the DNA joining step.