Question

Cup-shaped chloroplast is present in
A. Spirogyra
B. Chlamydomonas
C. Ulothrix
D. Chara

Answer 1

Chloroplasts are organelles present in photosynthetic organisms. The chloroplast or plastids consist of chlorophylls that are green pigments that help in photosynthesis. Chloroplasts are present in algae cells and plants. Cup-shaped chloroplasts are broad at the base and thin from walls that are positioned in an upright manner. These are present in green algae species that can also be found in snow as snow algae.

Complete answer: The chloroplasts also are known as plastids. These are organelles that are present in various algae cells and plant cells. It ranges widely in number from species to species. In algae, cell chloroplast can be one in number, whereas in plant cells they can range between 100 in number. The chloroplasts are photosynthesis conducting organelles. They contain a pigment called chlorophyll that is a green pigment that helps to conduct photosynthesis. The chloroplasts capture sunlight energy and convert it into energy in the form of energy molecules like ATP. Chlamydomonas is also a green algae species. These are found in a wide range of habitats including extreme environments. They live in freshwater, damp soils, stagnant waters, and even on the snow as ‘snow algae.’ These are used for various molecular biology experiments for understanding their chloroplast working. The characteristic feature of Chlamydomonas is the presence of a cup-like chloroplast. It is broad at base and thin from walls that are positioned in an upright manner.
a) Spirogyra is a charophyte green algae characterized by the presence of a spirally arranged chloroplast. It is found majorly in freshwater habitats.
b) Ulothrix is also a green algae species that are filamentous and non-branching. They are found in low-temperature areas. It does not have chloroplast.
c) Chara is charophyte algae having leaf-like and stem-like appearance due to which they resemble land plants. They are found in freshwater regions especially near limestone areas.
Therefore, the correct answer is option B.

Note: The Chlamydomonas is a model organism in molecular biology studies. They are famous for their flagella mechanics and chloroplast dynamics. Another special feature of Chlamydomonas is that they contain ion channels that are activated directly by light.