2. Wherefs gene located? ( 1 makk) 3. The point on the chromosome where gene is located is kno 5. What are nucleic acids? ( 2 marks). 16. What is the basic concept of gene, chromosome and DNA? 7. What are chromosomes? ( 2 marks), 8. Why is gene regarded as the basis for modern interpretation 9. Why is DNA exceptionally suited to be the genetic material 10. Depict the structure of a nucleoside and nucleotide and disc RNA with regards to their stability ( 4.5 marks) 14. Why is DNA exceptionally suited to be the genetio material 12. What are the components of the mucleic acid backbone? (1.2 13. What is the difference between ? mutation and a mutagen? 14 . Why is it important that the DNA double helix maintain def 15. Write short notes on the following: (2 marks each) 16 . (i). Cistron (ii). Muton (iii) Recon

Let's break down the questions and provide detailed answers for each one. ### 2. Where is the **fs** gene located? The **fs** gene, which is often referred to in the context of the **Fas** gene, is located on chromosome 10 in humans. Specifically, it is found at the locus 10q24.3. ### 3. The point on the chromosome where a gene is located is known as: The point on the chromosome where a gene is located is known as its **locus**. ### 5. What are nucleic acids? (2 marks) Nucleic acids are biopolymers essential for all forms of life. They are composed of long chains of nucleotides, which are the building blocks of nucleic acids. There are two main types of nucleic acids: - **DNA (Deoxyribonucleic Acid)**: Carries the genetic blueprint for the development, functioning, growth, and reproduction of all known organisms and many viruses. - **RNA (Ribonucleic Acid)**: Plays a crucial role in translating the genetic information from DNA into proteins and is involved in various biological roles, including coding, decoding, regulation, and expression of genes. ### 16. What is the basic concept of gene, chromosome, and DNA? - **Gene**: A gene is a segment of DNA that contains the instructions for building a specific protein or set of proteins. It is the basic unit of heredity. - **Chromosome**: A chromosome is a long, continuous thread of DNA that contains many genes. Chromosomes are found in the nucleus of eukaryotic cells and are responsible for the transmission of genetic information during cell division. - **DNA**: DNA is the molecule that carries the genetic instructions for life. It is composed of two strands that coil around each other to form a double helix, with each strand made up of nucleotides containing a sugar, a phosphate group, and a nitrogenous base. ### 7. What are chromosomes? (2 marks) Chromosomes are structures within cells that contain DNA and proteins. They are found in the nucleus of eukaryotic cells and are responsible for the organization, storage, and transmission of genetic information. Each species has a characteristic number of chromosomes; for example, humans have 46 chromosomes (23 pairs). Chromosomes ensure that DNA is accurately replicated and distributed during cell division. ### 8. Why is a gene regarded as the basis for modern interpretation? A gene is regarded as the basis for modern interpretation because it serves as the fundamental unit of heredity and biological function. The understanding of genes has led to significant advancements in genetics, molecular biology, and biotechnology. It allows scientists to explore how traits are inherited, how genetic disorders arise, and how organisms develop and function at a molecular level. ### 9. Why is DNA exceptionally suited to be the genetic material? DNA is exceptionally suited to be the genetic material for several reasons: - **Stability**: The double helix structure of DNA provides stability and protection for the genetic information. - **Replication**: DNA can be accurately replicated, ensuring that genetic information is passed on during cell division. - **Information Storage**: DNA can store vast amounts of information in the sequence of its bases. - **Mutability**: DNA can undergo mutations, which allows for genetic diversity and evolution. ### 10. Depict the structure of a nucleoside and nucleotide and discuss RNA with regards to their stability (4.5 marks) - **Nucleoside**: A nucleoside consists of a nitrogenous base (adenine, guanine, cytosine, or uracil in RNA) attached to a sugar (ribose in RNA). - **Nucleotide**: A nucleotide is a nucleoside with one or more phosphate groups attached. It is the basic building block of nucleic acids. **Stability of RNA**: RNA is generally less stable than DNA due to the presence of the hydroxyl group (-OH) on the ribose sugar, which makes it more susceptible to hydrolysis. This instability is beneficial for its role in protein synthesis, allowing RNA to be rapidly synthesized and degraded as needed. ### 12. What are the components of the nucleic acid backbone? (1.2 marks) The components of the nucleic acid backbone are: - **Sugar**: In DNA, it is deoxyribose; in RNA, it is ribose. - **Phosphate Group**: The phosphate groups link the sugars of adjacent nucleotides, forming the backbone of the nucleic acid strand. ### 13. What is the difference between a mutation and a mutagen? - **Mutation**: A mutation is a change in the DNA sequence that can lead to alterations in gene function or expression. Mutations can occur naturally or be induced by external factors. - **Mutagen**: A mutagen is an agent (chemical, physical, or biological) that causes mutations in the DNA. Mutagens can increase the frequency of mutations and may lead to genetic disorders or cancer. ### 14. Why is it important that the DNA double helix maintain its structure? It is important for the DNA double helix to maintain its structure because: - **Stability**: The double helix structure provides stability to the genetic material, protecting it from damage. - **Replication**: The complementary base pairing allows for accurate replication of DNA during cell division. - **Gene Expression**: The structure is essential for the proper functioning of proteins that interact with DNA, such as transcription factors and polymerases. ### 15. Write short notes on the following: (2 marks each) #### (i) Cistron A cistron is a segment of DNA that encodes a single polypeptide chain. It is synonymous with a gene and is the functional unit of heredity. The term emphasizes the role of the cistron in producing a specific protein. #### (ii) Muton A muton is the smallest unit of mutation that can occur within a gene. It refers to the specific nucleotide sequence that, when altered, results in a change in the function or expression of the gene. Mutons are often used in genetic studies to understand the effects of mutations. #### (iii) Recon A recon is the smallest unit of genetic recombination. It refers to the segment of DNA that can undergo recombination during processes such as meiosis. Recons are important for understanding genetic diversity and the inheritance of traits. These answers provide a comprehensive overview of the topics related to genetics and molecular biology. If you have any further questions or need clarification on any point, feel free to ask!