ESAT Biology B.6 Genetic Engineering

What is genetic engineering?

The process of taking a gene from one organism and inserting it into the DNA of another organism.

What does GMO stand for?

Genetically Modified Organism.

What is a restriction enzyme used for in genetic engineering?

To cut DNA at specific sequences, producing sticky ends.

What is DNA ligase used for in genetic engineering?

To join the ends of DNA fragments together, creating recombinant DNA.

What is a plasmid?

A small, circular piece of DNA in bacteria used as a vector to carry genes.

What is a recombinant plasmid?

A plasmid that has been altered to include DNA from another source.

How are genetically modified bacteria useful?

They can produce human proteins like insulin, enzymes, antibiotics, or blood clotting factors.

Give an example of a genetically modified plant and its trait.

Bt cotton is resistant to the cotton bollworm pest.

What is the benefit of golden rice?

It is genetically modified to produce ß-carotene, helping prevent vitamin A deficiency.

Give one medical application of GMOs.

Production of human insulin by GM bacteria to treat diabetes.

What is gene therapy?

Introducing a therapeutic gene into a person’s cells to replace or fix a faulty gene.

What are totipotent stem cells?

Stem cells that can develop into a complete multicellular organism.

What are pluripotent stem cells?

Stem cells that can differentiate into almost any cell type but cannot form a whole organism.

What are multipotent stem cells?

Adult stem cells that can differentiate into a limited range of cell types.

Give one medical use of embryonic stem cells.

Replacing insulin-secreting cells in the pancreas to treat diabetes.

What is an induced pluripotent stem cell (iPSC)?

A stem cell made in the lab from adult body cells, reprogrammed to behave like pluripotent stem cells.

What is selective breeding?

Choosing animals with desirable traits to reproduce and pass on those traits to offspring.

How does selective breeding differ from natural selection?

Selective breeding is human-directed, while natural selection is driven by environmental pressures.

Give one disadvantage of selective breeding.

Reduces genetic variation, increasing the risk of inherited disorders.

Why is inbreeding a concern in selective breeding?

It increases the likelihood of recessive genetic conditions appearing in offspring.

Give an example of an ethical issue with selective breeding.

Breeding bulldogs for flat faces can cause breathing problems in the dogs.

Give one risk of using GMOs in medicine.

Long-term consequences are unknown because GM products have only been used for a short time.

Give one use of GM plants in medicine.

Developing edible vaccines for safer and cheaper vaccination.

How are GM pigs potentially useful?

They may provide human-like organs for transplants, reducing donor shortages.

What is a concern with using GM pigs for organ transplants?

Possible spread of disease from pigs to humans.

How have GM mosquitoes been engineered to reduce malaria?

They have a more efficient immune response that kills the malaria parasite.

What is a potential risk of releasing GM mosquitoes into the wild?

They could negatively affect wild insect populations.

What is the main purpose of gene therapy in body cells?

To add a therapeutic gene to treat diseases like cystic fibrosis.

Why is gene therapy on gamete cells controversial?

Changes would be passed to all offspring, causing long-term unknown effects.

Give one advantage of gene therapy in stem cells.

GM stem cells continually produce healthy red blood cells, potentially providing a long-term cure.

What is one risk of gene therapy?

If the therapeutic gene is inserted near a cancer-causing gene, it can trigger cancer.

What is a source of totipotent stem cells?

The zygote (fertilized egg).

Give one similarity between totipotent and pluripotent stem cells.

Both can differentiate into multiple cell types.

Give one difference between totipotent and pluripotent stem cells.

Totipotent cells can form a whole organism including placenta; pluripotent cells cannot.

Give two disadvantages of using stem cells in medicine.

Risk of cancer developing and possible immune rejection of transplanted cells.

Why are bacteria used as vectors in genetic engineering?

They have plasmids that can carry genes into cells.

What is a sticky end in DNA?

Short single-stranded overhangs at the ends of DNA cut by restriction enzymes that allow complementary base pairing.

What is the role of Agrobacterium tumefaciens in plant genetic engineering?

Its Ti plasmid can insert genes into plant genomes.

Give one use of GM crops.

Herbicide resistance, e.g., glyphosate-resistant soybeans.

What is Bt cotton?

Cotton genetically modified to resist the cotton bollworm pest.

Give one ethical concern of using GMOs in medicine.

Unknown long-term effects and moral objections to modifying life.

What is selective breeding?

Choosing animals or plants with desirable traits to reproduce, so offspring inherit these traits.

Give one similarity between natural selection and selective breeding.

Both result in traits becoming more common in a population over generations.

Give one difference between natural selection and selective breeding.

Selective breeding is guided by humans, while natural selection is driven by the environment.

What is the first step in selective breeding?

Select animals with desirable characteristics for breeding.

What is the second step in selective breeding?

Breed these selected animals together.

What is the third step in selective breeding?

Select the offspring with the most desirable characteristics.

What is the fourth step in selective breeding?

Breed the selected offspring together.

What is the fifth step in selective breeding?

Repeat the cycle over many generations.

What is the final outcome of selective breeding?

Desirable traits increase in frequency in the population.

Give an example of selective breeding in dogs.

Breeding wolves selectively for traits like tameness, intelligence, or obedience.

Give one disadvantage of selective breeding.

Reduces genetic variation, increasing risk of inherited genetic conditions.

Give one ethical concern of selective breeding.

Traits selected by humans may harm animal welfare, e.g., bulldogs with breathing problems.

How can reduced genetic variation affect farm animals?

The population may be unable to adapt to new diseases or environmental changes.

Why is inbreeding a problem in selective breeding?

It increases the chance of homozygous recessive alleles causing genetic disorders.

Give one example of a genetic condition caused by selective breeding.

Inherited cataracts in bichon frise dogs or inherited hearing loss in Dalmatians.