Question

Identify the correct statement from the following.
A. The endomembrane system includes plasma membrane, ER, Golgi complex, lysosomes, ribosome and vacuoles
B. ER helps in the transport of substances, synthesis of proteins, lipoproteins and glycogen
C. Ribosomes are involved in protein synthesis
D. Mitochondria help in oxidative phosphorylation and generation of ATP

a. (B), (C), and (D)
b. (A)
c. (B)
d. (C)
e. (D)

Answer 1

Hint: The endomembrane system contains the ER, Golgi complex, lysosomes, ribosomes, nuclear membrane, etc. The endoplasmic reticulum involves protein synthesis, lipid synthesis, etc. Ribosomes are attached to the ER. Mitochondria are the sites of aerobic respiration and are called the powerhouse of the cell.

Complete answer:
> Endomembrane system- The eukaryotic cells have other membrane-bound distinct structures called organelles like the endoplasmic reticulum, the Golgi complex, lysosomes, mitochondria, microbodies, and vacuoles. These are called endomembrane systems because their functions are synchronized.

> Endoplasmic reticulum- Rough endoplasmic reticulum is often found in the cells and is involved in protein synthesis and secretion. They are continuous and extensive with the outer membrane of the nucleus. In the smooth endoplasmic reticulum there occurs the synthesis of lipids. Lipid like steroidal hormones are synthesized in SER of animal cells

> Ribosomes- These are small particles that consist of RNA and associated proteins that are involved in the synthesis of protein.

> Mitochondria- These are the double membrane-bound structure and are the sites of aerobic respiration. They produce cellular energy in the form of ATP, hence they are called the powerhouse of the cell. The matrix of mitochondria possess ribosomes for protein synthesis.

Hence, the correct answer is option (a) that is (B), (C), and (D)

Note: The endoplasmic reticulum bearing ribosomes on their surface is called the rough endoplasmic reticulum. When ribosomes are absent they appear smooth and are called the smooth endoplasmic reticulum. Ribosomes are not true organelles and can be found attached to the endoplasmic reticulum, in the mitochondrial matrix or they are seen floating in the cytoplasm.