To solve the problem, we need to identify the scientist who confirmed that the genetic nature of TMV (Tobacco Mosaic Virus) is RNA.
1. Understanding the TMV and RNA Discovery:
The discovery that the genetic material of the Tobacco Mosaic Virus (TMV) is RNA was confirmed through experiments conducted by various scientists. In particular, the work of Frankel-Conrat provided definitive evidence that the RNA is responsible for the viral properties of TMV.
2. Analyzing the Options:
Stanley: Although Stanley made important contributions to the study of TMV, the confirmation that TMV's genetic material is RNA is attributed to Frankel-Conrat.
Beijerinck: Beijerinck is known for his work on viruses, but he did not confirm that the genetic material of TMV is RNA.
Frankel-Conrat: Frankel-Conrat is the correct scientist who confirmed that TMV's genetic material is RNA, through experiments involving the isolation and characterization of the virus.
Iwanowski: Iwanowski is known for his discovery of the concept of viruses but did not specifically confirm that TMV's genetic material is RNA.
3. Conclusion:
Based on the historical contributions to the understanding of TMV and RNA.
Final Answer:
The correct option is (C) Frankel-Conrat.
Match the following:

Choose the correct pair from the following:

Identify A, B, C plants in a series based on these characters of roots:
A. Roots at lower nodes of stem
B. Roots absorb water and food from host plant
C. Root forming nodules
Plants which perform photosynthesis by these parts:
a) Ribbon like roots
b) Fleshy cylindrical stem
c) Needle like stem
d) Flattened stem
Find the correct statements regarding the structure of xylem and phloem:
I. Xylem parenchyma store starch or fat or Tannins
II. Xylem parenchyma have highly thickened walls and obliterated central lumens
III. Companion cells are controlled by nucleus of sieve tubes
IV. Phloem parenchyma is absent in most of the monocots
From the diagram answer the following:


Find incorrect statements related to water relations in plants:
A. Water potential difference is the drawing force for osmosis.
B. The driving force of diffusion is the concentration gradient.
C. Pressure potential is negative.