CBSE Questions for Class 11 Medical Biology Cell The Unit Of Life Quiz 7 - MCQExams.com

• A nuclear membrane, also known as the nuclear envelope, nucleolemma, or karyotheca, is the double lipid bilayer membrane that surrounds the genetic material and nucleolus in eukaryotic cells.
• The nuclear membrane consists of two lipid bilayers - the inner nuclear membrane, and the outer nuclear membrane. The space between the membranes is called the perinuclear space, a region contiguous with the lumen (inside) of the endoplasmic reticulum.
• The nuclear membrane has many small holes called nuclear pores that allow material to move in and out of the nucleus. Rough endoplasmic reticulum produces a nuclear envelope in telophase.

Correct Option: C

Explanation:

• Peptidoglycan (murein) is the major component of the bacterial cell wall.
• This peptidoglycan covering gives the cell shape and surrounds the cytoplasmic membrane
• N-acetyl glucosamine (NAG) and N-acetyl muramic acid (NAM) are the structural components of peptidoglycan.

Hence, the cell wall of prokaryotes is made up of peptidoglycan.

$$\textbf{Correct option: A}$$

$$\textbf{Solution:}$$

$$\textbf{Explanation for incorrect statement:}$$

Statement A:

$$\bullet$$ Lysosomes budded off or formed from the Golgi apparatus and contain digestive enzymes, but they are not double membranous vesicles. They are enclosed by single membrane.

$$\bullet$$ Lysosomes are found in the majority of animal cells. These are spherical vesicles that contain hydrolytic enzymes capable of degrading a wide range of biomolecules.

$$\textbf{Explanation for correct statements:}$$

Statement B:

$$\bullet$$ Endoplasmic reticulum is a continuous membrane system found within the cytoplasm of eukaryotic cells that forms a series of flattened sacs or tubules.

$$\bullet$$ It performs a variety of functions, including protein synthesis, folding, modification, and transport.

$$\bullet$$ There are two types of endoplasmic reticulum which are rough endoplasmic reticulum and smooth endoplasmic reticulum.

$$\bullet$$ Rough endoplasmic reticulum exhibits a rough appearance because ribosomes are bounded on its surface.

Statement C:

$$\bullet$$ Leucoplasts are a kind of plastids that are double-membranous structures.

$$\bullet$$ They lack pigment and thus, are not green in color. So, these are present in the non-photosynthetic parts of the plant like roots, seeds, etc.

$$\bullet$$ They contain their own DNA as well as protein-synthesizing machinery.

Statement D:

$$\bullet$$ Spherosomes are the single membrane-bound cell organelle.

$$\bullet$$ They take part in the synthesis and storage of lipids.

$$\bullet$$ They are also called plant lysosomes as they contain hydrolytic enzymes.

Hence the correct option is option A.

• The endoplasmic reticulum is a large network of membrane-bound tubes. The flattened membrane-enclosed sacs or tube-like structures of the endoplasmic reticulum is known as cisternae. 
• The endoplasm is the inner core of the cytoplasm and the membranes of the ER are continuous with the outer nuclear membrane.
  
  Hence, option D is correct.