Consider statements about viruses: 1. They possess both DNA and RNA. 2. They are obligate intracellular parasites. 3. They can be crystallized. Which are correct? MCQ with Answer and Explanation
Consider statements about viruses: 1. They possess both DNA and RNA. 2. They are obligate intracellular parasites. 3. They can be crystallized. Which are correct?
A. 1, 2 and 3
B. 2 and 3 only
C. 1 and 3 only
D. 1 and 2 only
Answer: Option B
Solution (By JKExamLibrary)
Viruses are unique entities containing either DNA or RNA, never both simultaneously, enclosed in a protein capsid. They are obligate intracellular parasites, requiring a host cell's machinery to replicate. Despite being biological entities, they can be crystallized like chemicals, as demonstrated by W.M. Stanley with TMV. Thus, statements 2 and 3 are correct.
Explanation:
The pollen grain contains the male gametophyte, which produces two sperm cells. The ovule contains the female gametophyte (embryo sac). Endosperm is the triploid nutritive tissue formed after double fertilization.
Explanation:
Hexokinase phosphorylates glucose to glucose-6-phosphate using ATP, the first step of glycolysis. Phosphofructokinase is the third step, pyruvate kinase the last, glucose-6-phosphatase reverses the reaction in gluconeogenesis.
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