Question

chloroplast of Chlamydomonas is
A. Cup- shaped
B. Star- shaped
C. Ribbon- shaped
D. Lamellate

Answer 1

Hint:-Chlamydomonas is a genus of unicellular algae (Chlorophyta) which includes 325 species of unicellular flagellates. It is a single - celled unicellular algae which is oval in shape and has a non - cellulosic membrane (theca), chloroplast, and a stigma (eyespot).

Complete step-by-step solution:-
Chlamydomonas is the most common unicellular volvocales and one of the simplest unicellular algae. It has two flagella, contractile vacuoles, eye-spot (orange - red pigment spot), chloroplast, pyrenoid, and nucleus. Eye – spots direct the movement of the individual as they are very sensitive to intensity of light. Chloroplast is an organelle within the cells, which consist of pigmented bodies (chlorophyll a & b). Chloroplast is also the site of photosynthesis where light energy is absorbed from the sun to produce free energy stored in ATP and NADPH. In this way, it helps to sustain life on Earth via helping plant cells to produce their own food. The green colour of algae (chlorophyta) is due to the presence of excess chlorophyll in chloroplasts. In some of the unicellular green algae such as Chlamydomonas, oxygen deficiency triggers induction of chloroplast - located, oxygen sensitive dehydrogenase, which accepts electrons from reduced ferredoxin to convert proton into molecular hydrogen. Chlamydomonas have cup – shaped chloroplasts.
The correct answer is A- Cup shaped.

Note:-
Chlamydomonas species are mostly used as models for research purposes in cell biology and molecular biology for fundamental questions studies of flagellar motility, chloroplast dynamics, genetics, and biogenesis. Most salient feature of chlamydomonas is that it has channelrhodopsin (ion channels) that are directly activated by light.