Read the following four statements (A-D)
(A) Depending on the ease of extraction, membrane proteins can be classified as hydrophobic and hydrophilic.
(B) Cell membrane is composed of lipids that are arranged in mono layer.
(C) The lipids are arranged within the membrane with the non polar head towards outer side and the hydrophilic tail towards the inner side
(D) Phagocytosis and pinocytosis are collectively termed as endocytosis.
Which of the above statements are wrong ?

Options

A. C & D
B. A, B & C
C. Only D
D. B & D

Answer

To determine which of the statements (A-D) are wrong, we will analyze each statement one by one.

**Step 1: Analyze Statement A**
Statement A claims that "Depending on the ease of extraction, membrane proteins can be classified as hydrophobic and hydrophilic."
- Membrane proteins are generally classified into two categories: integral (or intrinsic) proteins and peripheral (or extrinsic) proteins. While some integral proteins can be hydrophobic and some peripheral proteins can be hydrophilic, the classification based solely on hydrophobicity and hydrophilicity is misleading. Therefore, this statement is **incorrect**.

**Step 2: Analyze Statement B**
Statement B states that "Cell membrane is composed of lipids that are arranged in mono layer."
- The cell membrane is actually composed of a phospholipid bilayer, not a monolayer. This bilayer consists of two layers of phospholipids. Hence, this statement is also **incorrect**.

**Step 3: Analyze Statement C**
Statement C claims that "The lipids are arranged within the membrane with the non-polar head towards the outer side and the hydrophilic tail towards the inner side."
- This statement is incorrect because in a phospholipid bilayer, the hydrophilic (water-loving) heads face the aqueous environment (outer side), while the hydrophobic (water-fearing) tails face inward, away from water. Thus, this statement is **incorrect**.

**Step 4: Analyze Statement D**
Statement D states that "Phagocytosis and pinocytosis are collectively termed as endocytosis."
- This statement is correct. Both phagocytosis (cell eating) and pinocytosis (cell drinking) are forms of endocytosis, which is the process by which cells engulf substances from their external environment. Therefore, this statement is **correct**.

**Conclusion:**
The statements that are incorrect are A, B, and C.

**Final Answer:** Statements A, B, and C are wrong.

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