In the context of human diseases, 'Kala-azar' is a severe parasitic disease. The vector for this disease is the:
A. Female Phlebotomus sandfly
B. Female Aedes mosquito
C. Female Anopheles mosquito
D. Female Culex mosquito
Answer: Option A
Solution (By JKSSB Mock Tests)
Kala-azar, also known as visceral leishmaniasis, is a severe systemic disease caused by the protozoan parasite Leishmania donovani. The disease is transmitted to humans through the bite of an infected female Phlebotomus sandfly (in the Old World) or Lutzomyia sandfly (in the New World). The sandfly injects the infective promastigote stage of the parasite into the skin during a blood meal. Anopheles transmits malaria, Aedes transmits dengue and yellow fever, and Culex transmits filariasis.
Explanation:
Myosin is the motor protein forming thick filaments; its heads bind to actin thin filaments and generate force via the cross-bridge cycle. Actin forms thin filaments, troponin and tropomyosin regulate contraction. The sliding filament theory describes muscle shortening without filament length change.
Explanation:
The Competitive Exclusion Principle, formulated by G.F. Gause based on his experiments with Paramecium, states that two species with identical ecological niches (competing for the exact same limited resources) cannot coexist indefinitely in the same habitat. One species will inevitably have a slight reproductive advantage and will outcompete the other, leading to the local extinction or evolutionary shift (resource partitioning) of the inferior competitor.
No comments yet. Be the first to start the discussion!