Question

question
which of the following groups of organelles accurately represents those that are typically not present in circulating red blood cells?
answer
nucleus, endoplasmic reticulum, and cytoskeletal elements
mitochondria, golgi apparatus, and cytoskeletal elements
nucleus, mitochondria, and cytoskeletal elements
nucleus, mitochondria, and ribosomes
i dont know yet

Explanation:

Circulating red blood cells (RBCs) are highly specialized cells. During their maturation, they lose many organelles. The nucleus is extruded as RBCs mature. Mitochondria are not present as mature RBCs rely on anaerobic glycolysis for energy. Ribosomes are also absent as RBCs do not synthesize proteins (after losing the nucleus and ribosomes during maturation). Cytoskeletal elements are present in RBCs (like spectrin, actin etc. which help in maintaining the biconcave shape). The endoplasmic reticulum and Golgi apparatus are not relevant here as the key absent organelles are nucleus, mitochondria and ribosomes.

Answer:

Nucleus, mitochondria, and ribosomes