Question

Which of the following statements is/are correct?
I. The chromosomal movement during meiosis had been worked out by 1902.
II. Mendel suggested that factors are discrete units and was able to provide physical proof for its existence.
III. Advancements in microscopy helped scientists to carefully observe cell division and discover chromosomes.

• A. Statements (I) and (II) are correct, but statement (III) is incorrect
• B. Statements (I) and (II) are incorrect, but statement (III) is correct
• C. Statements (I) and (III) are correct, but statement (II) is incorrect
• D. All statements are correct

Answer 1

The correct option is C Statements (I) and (III) are correct, but statement (II) is incorrect

With the advancements in microscopy, the scientists were able to observe structures inside the nucleus and also cell division (mitosis and meiosis) more clearly. This led to the discovery of chromosomes (they divide during cell division).

During meiosis, the chromosomes get segregated and move towards the opposite poles to get equally distributed in the daughter cells. This was possible to view only due to advancements in microscopy. By 1902, the chromosomal movement during meiosis had been worked. Sutton and Boveri noted that the behaviour of chromosomes was parallel to the behaviour of Mendelian factors (genes). This helped them to explain Mendel’s laws.

Mendel suggested that factors are discrete units that are being passed on from parents to offspring and they contain information for the expression of the trait. But he could not provide any physical evidence about what the factors are made of.