Question

. (i) What is cell wall? From which substance the

plant cell wall is made up of and why? [2]

(ii) Explain the structure of nucleus. [2]

(iii) What is nucleoid?​

Answer 1

Explanation:

The cell wall is composed of a network of cellulose microfibrils and cross-linking glycans embedded in a highly cross-linked matrix of pectin polysaccharides. In secondary cell walls, lignin may be deposited.

The nucleus is an organelle found in eukaryotic cells. Inside its fully enclosed nuclear membrane, it contains the majority of the cell's genetic material. This material is organized as DNA molecules, along with a variety of proteins, to form chromosomes.

The nucleoid is the space within a prokaryotic cell where the genetic information, called the genophore, is found. Prokaryotes are divided into bacteria and archaea, which are both unicellular organisms that contain no membrane-bound organelles. The nucleoid, then, also has no membrane around it.

Answer 2

1. The cell wall is composed of a network of cellulose microfibrils and cross-linking glycans embedded in a highly cross-linked matrix of pectin polysaccharides. In secondary cell walls, lignin may be deposited.

2. The nucleus is a sphere-shaped organelle found in eukaryotic cells. It contains the genetic material of the cell in the form of nucleic acids. It is responsible for controlling all activities of the cell. and contains a nuclear membrane, chromosomes, nucleolus and nucleoplasm.

3. Nucleoid is the undefined nuclear region containing only nucleic acids, in the prokaryotic cells. ... It transports the material in and out of the cell. It is also reponsible for the formation of lysosomes.