Consider the following statements about the nervous system: 1. The central nervous system consists of the brain and spinal cord. 2. The peripheral nervous system includes cranial and spinal nerves. 3. The autonomic nervous system controls voluntary actions. Which of the above is/are correct? MCQ with Answer and Explanation
Consider the following statements about the nervous system:
1. The central nervous system consists of the brain and spinal cord.
2. The peripheral nervous system includes cranial and spinal nerves.
3. The autonomic nervous system controls voluntary actions.
Which of the above is/are correct?
A. 2 and 3 only
B. 1 and 2 only
C. 1, 2, and 3
D. 1 and 3 only
Answer: Option B
Solution (By JKSSB Mock Tests)
CNS = brain + spinal cord; PNS = nerves. Autonomic NS controls involuntary actions, so 3 is incorrect. Thus, 1 and 2 are correct.
Explanation:
DNA polymerase catalyzes the formation of phosphodiester bonds between adjacent nucleotides, extending the new strand complementary to the template. Helicase unwinds DNA, ligase joins fragments, primase synthesizes RNA primer. In prokaryotes, DNA polymerase III is the main replicative enzyme.
Explanation:
Enterokinase (enteropeptidase) is secreted by the intestinal mucosa and activates the pancreatic proenzyme trypsinogen to trypsin, which then activates other zymogens. Pepsin is active in the stomach, renin is a milk-curdling enzyme (chymosin), carboxypeptidase is a pancreatic protease. This cascade ensures that protein-digesting enzymes are activated only in the appropriate location to prevent autodigestion.
Explanation:
Fossils are direct evidence showing transitional forms. Lamarck proposed use and disuse, not natural selection. Analogous organs do not indicate common ancestry; homologous do. Appendix is vestigial.
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