Question

Assertion: Chara is a stonewort algae, close to Bryophyta
Reason: It has jacketed sex organs

A. Both Assertion and Reason are correct and Reason is the correct explanation for assertion.
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
C. Assertion is correct but reason is incorrect.
D. Assertion is incorrect but reason is correct.

Answer 1

Hint: Chara is the genus of green algae within the family Characeae. They are multicellular and superficially resemble land plants due to stem like and leaf like structures.

Complete answer:
Chara is a freshwater green algae mainly found in lakes, freshwater ponds and slow running water. They are multicellular and resemble land plants superficially. They need less hard and oxygenated water. They are coated with layers of calcium carbonate and are known as stonewort. They resemble the higher plants and in their structure there is a root like rhizoids, the whorl of branches at some intervals and an erect cylindrically axis which is shielded by small cells.
Chara reproduces by sexual as well as vegetative phases. An advanced oogamous form is the sexual reproduction of Chara, these cells are broad and macroscopic. The male sex organ called globule is yellow to red in colour. The female sex organ called oogonium is of green colour. On maturity, antheridia filaments made up of antheridium cells grow into the globules. The sex organs are jacketed. Oogonium is found separately above the globule. The reproductive structures are surrounded by sterile cells which resemble Bryophyta.
The zygote grows into an oospore after fertilization. They are mainly found in the northern temperate region, where they grow underwater and are joined by the muddy bottom. The body of the plant is gametophyte which is differentiated into nodes and internodes, tiny growth branches, the rhizoids and the needle shaped structures at the base of lateral secondary branches.

Hence, the correct answer is option (A).

Note: Chara is surrounded with calcium carbonate and is called stonewort. Cyanobacteria are found growing as epiphytes on the surface of Chara, where they’ll be involved in fixing nitrogen which is vital to plant nutrition.