Question 1: Genetic engineering involves modifying an organism's DNA to introduce desirable traits. This process often uses enzymes like restriction endonucleases and vectors such as plasmids to transfer genes between organisms.

Answer: Genetic engineering is the process of altering an organism's DNA to change or introduce specific traits using enzymes and vectors.

Question 1: Define the term 'restriction enzyme'.

Answer: A restriction enzyme is an enzyme that cuts DNA at specific sequences.

Question 2: Explain the role of a plasmid in genetic engineering.

Answer: A plasmid acts as a vector to carry foreign genes into an organism's cells during genetic engineering.

Question 3: What is meant by 'gene cloning'?

Answer: Gene cloning is the process of making multiple copies of a specific gene.

Question 1: A restriction enzyme cuts DNA at a recognition site every 4 base pairs on average. How many cuts would occur in a DNA molecule of 20,000 base pairs?

Answer: Number of cuts = Total base pairs / Recognition site length = 20,000 / 4 = 5,000 cuts.

Question 2: If a plasmid is 3 kilobases (kb) long and a foreign gene of 1.5 kb is inserted into it, what is the total size of the recombinant DNA molecule?

Answer: Total size = plasmid size + inserted gene = 3 kb + 1.5 kb = 4.5 kb.

Question 1: Describe a basic experimental setup to insert a gene into a bacterial plasmid, including key steps and safety precautions.

Answer: First, isolate the target gene using restriction enzymes. Then, cut the plasmid with the same enzyme. Mix the gene and plasmid with DNA ligase to join them. Insert the recombinant plasmid into bacteria, then grow the bacteria to produce multiple copies. Safety precautions include wearing gloves, working in a sterile environment, and disposing of genetically modified material properly.

Question 1: A scientist inserts a gene into bacteria that produces insulin. After growth, 1 million bacteria are tested, and 85% produce functional insulin. What percentage of bacteria do not produce insulin? Explain what this might indicate about the process.

Answer: 15% of bacteria do not produce insulin. This may indicate incomplete gene insertion, mutation, or gene silencing in some bacteria.

Question 1: Describe one way genetic engineering is used to improve crop plants.

Answer: Genetic engineering is used to create pest-resistant or drought-tolerant crops by inserting specific genes.

Question 2: Explain the ethical considerations related to genetic engineering in humans.

Answer: Ethical considerations include concerns about safety, consent, potential for misuse, genetic inequality, and long-term effects on human health and biodiversity.