NEET 2026
- Exam
- NEET
- Year
- 2026
- Subject
- Biology
- Chapter
- Chapter
NEET 2026 · Biology · Chapter
Skoog and Miller (1955) identified and crystallised a...
Skoog and Miller (1955) identified and crystallised a cytokinesis-promoting active substance termed kinetin. From which of the following materials was it originally isolated?
Options
- AColeoptile tips of oat seedlings
- BAutoclaved herring sperm DNA
- CSterile culture filtrate of a fungus
- DVolatile emissions from ripened oranges
Correct answer
B. Autoclaved herring sperm DNA
Step-by-step solution
F. Skoog and his co-workers observed that from the internodal segments of tobacco stems, the callus proliferated only if, in addition to auxins, the nutrient medium was supplemented with one of the following: extracts of vascular tissues, yeast extract, coconut milk, or DNA.
Later, Skoog and Miller (1955) identified and crystallised the cytokinesis-promoting active substance from autoclaved herring sperm DNA and termed it kinetin.
Coleoptile tips of oat seedlings are associated with the discovery of auxins by F.W. Went.
Sterile culture filtrate of the fungus Gibberella fujikuroi is associated with the discovery of gibberellins by E. Kurosawa.
Volatile emissions from ripened oranges are associated with the discovery of ethylene by Cousins.
Answer: Autoclaved herring sperm DNA
Later, Skoog and Miller (1955) identified and crystallised the cytokinesis-promoting active substance from autoclaved herring sperm DNA and termed it kinetin.
Coleoptile tips of oat seedlings are associated with the discovery of auxins by F.W. Went.
Sterile culture filtrate of the fungus Gibberella fujikuroi is associated with the discovery of gibberellins by E. Kurosawa.
Volatile emissions from ripened oranges are associated with the discovery of ethylene by Cousins.
Answer: Autoclaved herring sperm DNA