Question

While working on Neurospora crassa, Beadle and Tatum proved that:
A. Every gene is responsible for a specific enzyme
B. Plant cells are totipotent
C. DNA replication is semi-conservative
D. Viruses have genetic material

Answer 1

Hint: Neurospora is prominently used for research purposes around the globe. During the experiment conducted by these scientists, it was observed that the spores produced were just reproductive cells containing DNA.

Complete answer:
Genes possess information encoded in the form of nucleotide sequences, which is required for the formation of proteins. A specific gene is responsible for the formation of a specific protein. In case of distortion of the gene, an organism is unable to produce that specific gene which is further reflected in the observable features of the organism. Beadle and Tatum conducted an experiment which clearly demonstrated using Neurospora. Neurospora crassa, belongs to the genus Ascomycetes, which is a type of red bread mould. It is used as a model organism for genetic experimentation purposes because it can grow easily. It has a haploid life cycle. This characteristic makes it easier to genetically analyse and draw inferences out of the experiment. They exposed mould spores to X-rays to induce mutations in DNA and grew mutated and unmutated spores together in a medium. They then grew the surviving spores in another medium and concluded that the mutated bread mould will be able to survive in both mediums. This was particularly due to the presence of a specific enzyme formed due to the presence of a specific gene.
Hence, the correct answer is option (A).

Additional information:
Neurospora is prominently used for research purposes around the globe. It is of great importance for conducting experiments with regard to follows:
a. Epigenetics and cell polarity
b. Cell fusion
c. Cell development
d. It is also useful in studying many other aspects of cell biology and biochemistry.

Note: The study proved that genes are responsible for giving the directions necessary to produce enzymes that control various metabolic processes. It is also noted that all enzymes are proteins, but all proteins are not enzymes.