Biology MCQs
Topic Notes: Biology
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
51
The term 'virus' is derived from the Latin word 'venome', which translates to what?
Answer:
Poisonous Fluid
The word virus originates from the Latin term 'virus', which historically referred to a poisonous or noxious fluid. This reflects early observations of infectious agents before their biological nature was fully understood.
52
What is the causative agent of bovine spongiform encephalopathy, commonly known as mad cow disease?
Answer:
Prion
Mad cow disease is caused by prions, which are misfolded proteins capable of inducing abnormal folding in normal cellular proteins. These infectious agents lead to progressive neurodegeneration and the formation of sponge-like holes in brain tissue.
53
What is the term for the interval between the initial infection by a pathogen and the appearance of the first clinical symptoms of a disease?
Answer:
Incubation period
The incubation period is defined as the time elapsed between exposure to a pathogenic organism and the manifestation of the first symptoms of the disease. During this phase, the pathogen multiplies within the host, but the host remains asymptomatic.
54
Which of the following organisms does not possess a cellular structure?
Answer:
Viruses
Viruses are acellular entities consisting primarily of genetic material (DNA or RNA) enclosed within a protein capsid. Unlike bacteria, fungi, and algae, they lack the metabolic machinery and organelles required to function independently, necessitating a host cell for replication.