Which structure forms the posterior part of the thoracic cage?

A. By controlling skeletal muscle contraction: Skeletal muscles are controlled by the somatic nervous system, not the autonomic nervous system, and are responsible for voluntary movements.

B. By controlling voluntary muscle movements: Voluntary muscle control is managed by the somatic nervous system, while the ANS operates involuntarily to maintain internal balance.

C. By regulating involuntary body functions: The ANS regulates involuntary activities such as heart rate, digestion, respiratory rate, and blood pressure, maintaining homeostasis without conscious effort.

D. By producing hormones: Hormone production is primarily the function of endocrine glands; the ANS influences some glands indirectly but does not produce hormones itself.

A. Ribosome: Ribosomes are responsible for protein synthesis by translating mRNA into amino acid sequences. They do not produce energy for the cell.

B. Nucleus: The nucleus stores genetic material and regulates cellular activities by controlling gene expression. It does not generate cellular energy directly.

C. Golgi apparatus: The Golgi apparatus modifies, sorts, and packages proteins and lipids for transport within or outside the cell. It is not involved in energy production.

D. Mitochondria: Mitochondria are the “powerhouses” of the cell, generating ATP through cellular respiration. They convert nutrients like glucose and fatty acids into usable energy to fuel cellular functions.