Question

Main Component of the middle lamella?
A. Mg Pectate
B. Calcium Pectate
C. Calcium Carbonate
D. Calcium Oxalate

Answer 1

Hint: The major component is a compound formed by an element which is present abundantly in dairy products. The element is also a macro element and its deficiency leads to meristem degeneration in the root apex.

Complete answer:
The middle lamella is a thin, amorphous cementing layer that helps in the joining of two adjacent plant cells. The main component of the middle lamella is calcium pectate.

Additional Information:
1. The composition and structure of the cell wall is as follows-
- Cell wall matrix is composed of water, hemicellulose, pectins, proteins, and lipids. Almost 60% is composed of water.
- The cell wall also consists of microfibrils like cellulose, hemicellulose. Cellulose is the major component.
- The cell wall is composed of four layers, which are middle lamella, primary wall, secondary wall, and tertiary wall.
- The primary wall is elastic and permeable. It is a single-layered and outermost part.
- The secondary wall again consists of three layers which are S1, S2, and S3. It is made up of cellulose, hemicellulose, and pectin. It may also contain lignin, suberin, and cutin. They make the cell wall impermeable and also help in strengthening.
- The tertiary cell wall is inner to the secondary cell wall. It shows different chemical properties due to the deposition of chemical substances known as xylans.
2. Pits- These are unthickened areas in the secondary cell walls of plant cells and are present as depressions. They consist of a pit chamber and pit membrane. Pits are mainly of two types, simple pits and bordered pits.
3. Plasmodesmata are cytoplasmic connections between two adjacent cells.
4. The growth of the cell wall occurs by accretion.

So, the correct answer is calcium pectate.

Note: It should be remembered that both calcium and magnesium pectate is present in the middle lamella but the major component is calcium pectate.