Transgenic organisms - class-XII

Agrobacterium tumefacians is used for the production of transgenic plants as it carries a plasmid capable of inducing tumors in plants. These tumors can be artificially induced by transferring the gene into a plant which otherwise is not prone to infection, where the plasmid is genetically engineered for inserting a particular gene, for example, the transfer of delta endotoxin and npt II gene, from Bacillus thuringiensis, in commercially useful plants like cotton to protect it from its predator, the gall worm

Transgenic plants are created by introducing a foreign gene (transgene) from another organism into the plant's genome, allowing it to express new traits.

A transgenic crop plant contains a gene or genes which have been artificially inserted instead of the plant acquiring them through pollination. The inserted gene sequence (known as the transgene) may come from another unrelated plant, or from a completely different species: transgenic Bt corn, for example, which produces its own insecticide, contains a gene from a bacterium. 

Transgenic animals are used for various purposes, including testing the safety of vaccines, assessing the toxicity of drugs, and producing pharmaceutical proteins.

Mice are the most commonly used transgenic animals in research due to their short reproductive cycle, ease of handling, and genetic similarity to humans.

A transgenic animal is defined as an animal that has had foreign DNA (exogenous DNA) introduced into its genome, which is then passed on to its offspring.

While many animals like sheep, pigs, rats, rabbits, cows, and fish have been genetically modified, dogs and banded kraits are not standard subjects for transgenic production.

• Dolly is the first sheep which was developed by the technique of cloning. 
• The sheep was developed from the diploid body cell. The somatic cell from the mother sheep was taken and the nucleus was injected into the egg cell.
• This egg cell was cultured and transferred to the surrogate mother. 
• The sheep Dolly was identical in the characters with the mother who donated the diploid nucleus from the body cell. 
• The genes from the mother cells were transferred to Dolly. 
• Thus, the correct answer is option A. 

• Escherichia coli is considered as a model organism. The organism can be cultured and maintained very easily in the laboratory conditions. 
• The genome of the prokaryotic bacteria has been mapped and the details about all the genes and the products have been known. 
• This makes it easy to modify or alter and gene, introduce a new gene or mutate the gene and study the effect. The organism can be easily studied as the growth rate is high. 
• So, many works related to genetics have been performed using this bacterium.
• Thus, the correct answer is option B. 

A reporter gene is a gene that researchers attach to a regulatory sequence of another gene of interest in bacteria, cell culture, animals or plants. It determines the action of transgene in transgenic plants and animals.

Pseudomonas fluorescens is a bacterium that has been genetically engineered to express proteins that inhibit ice crystal formation, providing frost resistance to plants.

Streptokinase is an enzyme produced by Streptococcus bacteria that acts as a clot buster by breaking down blood clots. It is produced commercially using genetic engineering.