Biotechnology & Genetic Engineering

Pronuclear transfer, in the context of human reproductive technology, is used for preventing mitochondrial diseases in offspring. Here's why - Mitochondria: These are cellular organelles with their own DNA (mitochondrial DNA or mtDNA) separate from nuclear DNA. Mutations in mtDNA can cause various inherited mitochondrial diseases that can affect organs like muscles, nerves, and the brain. - Pronuclear Transfer Technique: This technique involves the fertilization of an egg with sperm. Then, the pronuclei (nuclei before fusion) from both sperm and egg are removed. These pronuclei are then injected into a donor egg that has had its own pronuclei removed, but has healthy mtDNA.

Statement 1 is correct. Plant cells have rigid cell walls made of cellulose, a complex carbohydrate, which animal cells lack. Animal cells rely on a plasma membrane for structure and protection. Statement 2 is incorrect. Both plant and animal cells have a plasma membrane, a phospholipid bilayer that controls what enters and leaves the cell. It's a fundamental component for all cells. Statement 3 is correct. Mature plant cells typically have a single, large central vacuole that stores water, nutrients, and waste products. Animal cells can have vacuoles, but they are usually smaller and more numerous.

Statement 1 is correct. Carbon nanotubes are being explored for their potential use as drug and antigen carriers in the human body. Their unique properties allow them to attach drugs or antigens and deliver them to specific target cells. Statement 2 is incorrect. While research is ongoing, using carbon nanotubes for artificial blood capillaries in the human body is still in the theoretical or experimental stages. Statement 3 is correct. Carbon nanotubes show promise in developing biosensors due to their high electrical conductivity and sensitivity to changes in their environment. This makes them suitable for detecting biomolecules like enzymes, DNA, or toxins. Statement 4 is partially true. Some studies have found that carbon nanotubes are non-degradable, also some studies have shown them to be degradable. The official answer key of the UPSC has given 'C' as the correct answer.

Statement 1 is correct. Techniques like CRISPR-Cas9 allow the editing of genes in sperm or egg cells (germline cells) before fertilization. This can potentially correct genetic diseases passed on to future generations. Statement 2 is correct. Genome editing in early embryos CRISPR and other techniques can be used to edit genes in embryos at a very early stage of development. This allows for correcting genetic defects before implantation in the womb, potentially preventing the child from inheriting the disease. Statement 3 is correct. Scientists can reprogram adult human cells into induced pluripotent stem cells (hiPSCs) that have the potential to develop into any cell type. These hiPSCs can be injected into animal embryos, like pigs, to create chimeric embryos containing both human and animal cells. This technology is used for research purposes to study human development and disease. All three statements are correct.

In Andhra Pradesh, drones were banned from spraying fertilizers, however, it is practised in many parts of the world. In Peru, a crater was inspected with the help of drones. It has also been used for collecting water samples from aquatic animals to get their DNA data. All three functions mentioned have been performed in different parts of the world.

RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is a conserved biological response to double-stranded RNA that mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes. Statement 1 is correct. RNAi is a powerful tool for developing gene-silencing therapies. It allows researchers to target specific genes and reduce their expression, which can be beneficial in treating various diseases. Statement 2 is also correct. RNAi is being actively explored for cancer therapy. By targeting genes involved in cancer cell growth and proliferation, RNAi has the potential to be a novel approach for cancer treatment. Statement 3 is incorrect. RNAi is not typically used in developing hormone replacement therapies. Hormone replacement therapies introduce hormones into the body, while RNAi focuses on silencing gene expression within cells. Statement 4 is correct. RNAi can be used to develop crop plants resistant to viral pathogens. By introducing specific RNA molecules that target the virus, plants can be made more resistant to viral infections, improving agricultural yields.

* Cas9 protein is a revolutionary tool in the field of genetic engineering. * Cas9 is an RNA-guided endonuclease, an enzyme. It acts like molecular scissors, capable of cutting DNA at specific locations within a cell's genome. * Cas9 plays a crucial role in the CRISPR-Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats) technique, a powerful gene editing tool.

* The word 'Denisovan' is mentioned in the media about ancient humans (or an extinct human relative). * Denisovans were a mysterious group of archaic humans who lived in Asia tens of thousands of years ago. They are most known for being discovered through genetic analysis of fossils, rather than complete skeletal remains.

Option A is incorrect. While it is possible to create artificial DNA sequences in a laboratory, creating a fully functional chromosome by joining DNA segments from different species is not currently feasible. Chromosomes are complex structures, and recreating a functional chromosome from scratch is an extremely challenging task. Thus, Option B is correct. Advances in synthetic biology and genetic engineering have made it possible to create artificial DNA sequences with desired functions in a laboratory setting. Option C is correct. Techniques like in vitro DNA replication and polymerase chain reaction (PCR) allow for the replication of DNA fragments outside of a living cell, in a controlled laboratory environment. Option D is correct. Techniques like cell culture and tissue culture allow for the growth and division of cells taken from plants and animals in a controlled laboratory environment.

3D printing, also known as additive manufacturing, is a process of making three dimensional solid objects from a digital file. It is used in a wide range of industries and has various applications. It can be used to create intricate and customized shapes in confectionery items like chocolates, candies, and other desserts. It has been used to create customized bionic ears for people with hearing impairments. It is used in the automotive industry for rapid prototyping, manufacturing of customized parts, and even some production of vehicle components. It is used in reconstructive surgeries to create patient-specific implants, prosthetics, and surgical guides. It can be used to create specialized components and parts for data processing technologies, such as computer hardware. Therefore, all the five statements are correct.