Chromosomes are thread-like structures located in the nucleus of cells, composed of DNA and proteins. They carry genetic information essential for heredity and cell division. Each species has a specific number of chromosomes, which play a vital role in ensuring proper genetic inheritance.

Based on the number and position of the centromere, chromosomes can be classified into several types:

1. Metacentric Chromosomes: The centromere is located at the midpoint, resulting in two equal arms.

2. Submetacentric Chromosomes: The centromere is slightly off-center, leading to one arm being longer than the other.

3. Acrocentric Chromosomes: The centromere is situated near one end, creating a very short arm and a long arm.

4. Telocentric Chromosomes: The centromere is at the terminal end, resulting in only one arm.

These classifications help in understanding chromosome structure and behavior during cell division.

Gene therapy is a revolutionary medical technique that aims to treat or prevent diseases by modifying or replacing faulty genes. This approach is particularly effective for genetic disorders and certain cancers. By introducing healthy genes into a patient’s cells, gene therapy can restore normal function and alleviate symptoms.

In contrast, supportive therapy focuses on enhancing the quality of life for patients without directly addressing the underlying disease. It includes pain management, psychological support, and nutritional assistance. While supportive therapy helps manage symptoms and improve overall well-being, it does not cure or treat the disease itself. Thus, the key difference lies in gene therapy’s active intervention at the genetic level, while supportive therapy provides care and comfort.

(1) Benedict’s Test: Benedict’s test is a qualitative assay used to detect reducing sugars, such as glucose and fructose. In this test, Benedict’s reagent (a blue solution containing copper(II) sulfate) is mixed with the sample and heated. If reducing sugars are present, the solution changes color, typically from blue to green, yellow, or brick-red, indicating the presence and concentration of sugars.

(ii) Drug, Medicine, and Chemotherapy: A drug is a substance used to diagnose, treat, or prevent disease. Medicines are formulated drugs that can provide therapeutic effects for various health conditions. Chemotherapy refers specifically to the use of chemical agents to treat cancer. It targets rapidly dividing cells to inhibit their growth and replication, thereby reducing tumor size and preventing cancer progression.

Challenges to internal security through communication networks include cyber attacks and data breaches, declining network reliability, misuse of information, terrorist exploitation of technology, and legal/privacy issues. Additionally, the rapid evolution of communication tools complicates monitoring and response efforts for security agencies, making it difficult to prevent threats.

Natural hazards refer to potential events such as earthquakes or floods that can occur in nature, while natural disasters are significant events that cause severe damage, impacting human life, property, and the environment. The key difference lies in the severity and actual consequences of the events.