Question

Identify the wrong pair from the following.
A. Euglena-Binary Fission
B. Yeast- Budding
C. Spirogyra- Fragmentation
D. Hydra- Multiple fission

Answer 1

The mode of replication in Euglena, Yeast, Spirogyra and Hydra are different but the main similarity is all undergone asexual reproduction. Asexual reproduction results into progeny which are exact copies of the parents referred to as clones.

Complete answer: Unicellular organisms multiplied by simple cell division or mitosis. They don’t need special mechanisms to multiply like in multicellular organisms.
In option A, Euglena is a unicellular organism that has the characters of both plant cell and animal cell. It is a flagellated microorganism found in both freshwater, saltwater, and moist soil. It reproduced asexually through binary fission. In binary fission, the Euglena divides longitudinally into two new individuals.
In option B, Yeast is a unicellular eukaryotic fungus called Saccharomyces cerevisiae. It is used in fermentation processes as it converts carbohydrates to carbon dioxide and alcohol. As it produces carbon dioxide, it is used in bread-making processes. It multiplies using budding. Budding is a process in which small but multiple buds like structure appear on the parent body. These buds detach from the parent body and form a new individual.
In option C, Spirogyra is a water alga also known as water silk. It has a cylindrical body with chlorophyll in it. It is present in a freshwater alga and divides by fragmentation. In this, the Spirogyra simply breaks into pieces and each develops into a mature individual.
In option D, Hydra is a freshwater invertebrate, it rapidly regenerates. It divides by budding and not multiple fission.
Therefore, Option D is correct.

Note: Cell division is an important process for survival. It is vitally important in unicellular organisms as it is the mode of their reproduction. Hydra divides using budding while plasmodium divides by multiple fissions. In multiple fissions instead of two, many daughter cells are formed while in binary fission and fragmentation only two daughter cells are produced at a time.