Question

Consider the following statements
I. The endomembrane system includes plasma membrane, ER, Golgi complex, lysosomes and vacuoles.
II. ER helps in the transport of substances, synthesis of proteins, lipoproteins and glycogen.
III. Ribosomes are involved in protein synthesis.
IV. Mitochondria help in oxidatiove phosphorylation and generation of ATP.
Which of these statements is true?

• A. II, III and IV
• B. Only I
• C. Only II
• D. Only III
• E. Only IV

Answer 1

The correct option is A II, III and IV

The correct statements are II, III and IV.
The endomembrane system includes the nuclear envelope, ER, Golgi apparatus, lysosomes, vacuoles, vesicles, endosomes and cell membrane. Since nuclear membrane, endosomes and vesicles are absent in the statement, it is false.
Rough Endoplasmic Reticulum (RER) bears ribosomes on its surface and is actively involved in protein synthesis, secretion and transport of substances. Smooth Endoplasmic Reticulum (SER) is devoid of ribosomes and is the major site for synthesis of lipid. In animal cells, lipid-like steroidal hormones are synthesised in SER.
Ribosomes are the site of protein synthesis.
Mitochondria are the sites of aerobic respiration. They produce cellular energy in the form of ATP. Hence, they are called 'powerhouse' of the cell. Oxidative phosphorylation occurs on the inner membrane of mitochondria.