Question

In which group of organisms do the cell walls form two thin overlapping shells which fit together?

• A. Slime molds
• B. Chrysophytes
• C. Euglenoids
• D. Dinoflagellates

Answer 1

The correct option is B

Chrysophytes

The correct option is option B.

Explanation of the correct option:

1. The cell wall is made up of cellulose which is impregnated with glass-like silica.
2. It has two overlapping halves which fit together like two parts of a soap case.
3. It is called shell or frustule.
4. The upper half of the cell is called epitheca whereas the lower half is called hypotheca.

Explanation of the incorrect options:

Option A:

1. They belong to the group euglenoids.
2. They are more prevalent in the rainy season in cool, shady, and moist places.
3. The cell wall is present only in spores.
4. The other stages are surrounded by a plasma membrane.

Option C:

1. They do not have a cell wall.
2. The body is covered with a thin flexible pellicle.

Option D:

1. They have a rigid coat known as lorica.
2. They consist of two to many plates of cellulose.

Final answer: Chrysophytes have cell walls that form two thin overlapping shells which fit together.