Matching Scientists with Key Genetics Discoveries

This question asks us to match famous scientists from the field of genetics with their significant discoveries or contributions. Let's examine each scientist and their work provided in the lists.

Analyzing List-I Scientists and List-II Discoveries

We have four scientists in List-I and four discoveries in List-II:

List-I (Scientists):

• (A) Sutton and Boveri
• (B) Sturtevant
• (C) Henking
• (D) Griffith

List-II (Discovery):

• (I) X-Body
• (II) Chromosomal Theory of Inheritance
• (III) Transformation in bacteria
• (IV) Genetic maps

Step-by-Step Matching Process

Let's consider each scientist and link them to their correct discovery:

1. (A) Sutton and Boveri: Walter Sutton and Theodor Boveri independently proposed that chromosomes are the carriers of genetic information. Their work laid the foundation for the Chromosomal Theory of Inheritance, which states that Mendelian factors (genes) are located on chromosomes.
   Therefore, (A) matches with (II).
2. (B) Sturtevant: Alfred Sturtevant, a student of Thomas Hunt Morgan, used the concept of recombination frequency between genes on a chromosome to determine their relative positions. This led to the development of the first Genetic maps, which show the linear arrangement of genes on a chromosome.
   Therefore, (B) matches with (IV).
3. (C) Henking: Hermann Henking, while studying spermatogenesis in the firefly Pyrrhocoris apterus in 1891, observed a nuclear structure that he called the 'X-body'. This structure was later identified as the X-chromosome and was linked to sex determination.
   Therefore, (C) matches with (I).
4. (D) Griffith: Frederick Griffith conducted experiments in 1928 using Streptococcus pneumoniae bacteria. His experiment demonstrated that a substance from virulent bacteria could transform harmless bacteria into virulent ones. This phenomenon was called Transformation in bacteria, which later provided evidence that DNA was the genetic material.
   Therefore, (D) matches with (III).

Summary of Matches

Based on the analysis, the correct matches are:

• (A) - (II)
• (B) - (IV)
• (C) - (I)
• (D) - (III)

Tabular Representation of the Matching

The combination that represents the correct matches is (A) - (II), (B) - (IV), (C) - (I), (D) - (III).

Revision Table: Scientists and Genetics Discoveries

Additional Information on Genetics Concepts

Understanding these discoveries is fundamental to the study of genetics:

• Chromosomal Theory of Inheritance: This theory unified Mendelian genetics with chromosome behavior during meiosis, explaining how traits are inherited through chromosomes. It was a crucial step in establishing chromosomes as the physical basis of heredity.
• Genetic Maps: These maps show the relative locations of genes along a chromosome, based on recombination frequencies. They are essential tools for gene mapping, understanding chromosome structure, and studying evolutionary relationships.
• X-Body/Sex Chromosomes: The discovery of the X-body by Henking led to the identification of sex chromosomes (X and Y) and our understanding of the chromosomal basis of sex determination in many organisms.
• Bacterial Transformation: Griffith's experiment showed that genetic material could be transferred between bacterial cells. This paved the way for the identification of DNA as the genetic material by Avery, MacLeod, and McCarty, and is a key mechanism for genetic variation in bacteria.