Question

Chloroplasts present in Spirogyra are
A. Ribbon shaped
B. Spirally coiled
C. Studded with pyrenoids
D. All of the above

Answer 1

Hint: Chloroplasts are green plastids. They contain chlorophyll and other types of pigments. The chlorophyll pigment of the chloroplasts is mainly concerned with photosynthesis. Moreover, the chloroplast is a double membranous, semi-autonomous cell organelle.

Complete answer: Spirogyra is a type of algae. It belongs to the class of green algae or Chlorophyceae. Spirogyra is a type of filamentous form of green algae. Spirogyra has a haploid body. They are mainly present in freshwater. Only some algae are present in the marine water. The chloroplasts contain photosynthetic pigments like chlorophyll a and chlorophyll b. Spirogyra has thin and flat ribbon-shaped chloroplasts. These chloroplasts are spirally coiled in the structure. The chloroplasts present in Spirogyra have one or more pyrenoids present over them. These pyrenoids are food storing centers. They store the food mostly in the form of normal starch or carbohydrates. Thus, based on the above information we can conclude that the chloroplasts present in Spirogyra are ribbon-shaped, spirally coiled, and studded with pyrenoids.
Hence, the correct answer is option (D).

Note: The shape of the chloroplasts in green algae is highly variable. Some common types of green algae and the shape of their chloroplasts are given below –
a. Chlorella – It has a discoid or disc-shaped chloroplast.
b. Ulothrix – It has a girdle shaped or girdle like chloroplast.
c. Chlamydomonas – It has a cup-like or cup-shaped chloroplast.
d. Oedogonium – It has a reticulate chloroplast.
e. Zygonema – It has a star-shaped or star-like chloroplast.