Consider the following statements:
1. Plasma membrane is selective permeable
2. In a plant cell DNA is found in nucleus only
3. Ribosomes are present in both the bacteria and eukaryotic cells
4. How many of the statements given above are correct?

Correct option is B

The Correct answer is(b) Only two
Explanation:
 Statement 1 is correct. The  plasma membrane (or cell membrane) is a selectively permeable (or semi-permeable) membrane, meaning it allows certain molecules or ions to pass through it by means of active or passive transport, but not others.
 Statement 2 is incorrect. In a plant cell, DNA is found not only in the  nucleus but also in the  mitochondria and  chloroplasts.
 Statement 3 is correct.  Ribosomes are found in all living cells. Prokaryotic cells (like bacteria) have 70S ribosomes, while eukaryotic cells have 80S ribosomes in their cytoplasm (and 70S ribosomes within mitochondria and chloroplasts).
Information Booster:
 The fluid mosaic model proposed by Singer and Nicolson in 1972 describes the structure of the plasma membrane.
 Mitochondria and chloroplasts are semi-autonomous organelles, possessing their own DNA and ribosomes, which supports the endosymbiotic theory.
 Ribosomes are often referred to as "protein factories" as they are the site of protein synthesis (translation).
 The "S" in 70S and 80S stands for Svedberg unit, a measure of sedimentation rate, which is related to size and density.