Question

Which of the following algae shows physiological anisogamy?

• A. Spirogyra
• B. Ulothrix
• C. Volvox
• D. All of the above

Answer 1

The correct option is A Spirogyra

Sexual reproduction in Spirogyra occurs by the method of conjugation. Conjugation is the process of fusion of two gametes out of which one acting as the male gamete passes through the conjugation tube to the female gamete.

In Spirogyra all the cells of the filament can form the gametes, which are morphologically similar and are referred to as isogametes. This phenomena of sexual reproduction is known as isogamous type of sexual reproduction. But at the time of conjugation one of the two isogametes shows motility and is considered as the male gamete. This phenomenon is referred to as physiological anisogamy.