Question

Assertion: Algae show only anisogamous type of reproduction.
Reason: In algae, gametes can never be non-flagellated.
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 and Reason is incorrect
D) Both Assertion and Reason are incorrect

Answer 1

Hint: Algae are chlorophyll-bearing, autotrophic, simple, thalloid, and aquatic organisms. They can reproduce by asexual, vegetative and sexual method. Vegetative is done by fragmentation whereas the asexual is done by forming different spores.

Complete answer:
The algae also occur in a different type of habitat like moist stone, soils and wood. They can reproduce by the vegetative, asexual and sexual method. Vegetative reproduction is by fragmentation method. In this method, each fragment is developed into a thallus. They form a different type of spores in the asexual mode of reproduction. The most common type is the zoospores. These spores are flagellated (motile). They germinate and give rise to new plants. Sexual reproduction is done through the fusion of two gametes. If the fusion is between the same morphology gametes generally in terms of size and shape, this is called isogamous. These gametes can be flagellated or non-flagellated but similar in size. When the fusion takes place between the gametes of dissimilar in size and form are terms as anisogamous. Whereas when fusion takes place between a smaller and motile male gamete and large and non-motile female gamete is called oogamous.

Therefore the correct answer is option D.

Additional Information: Algae are very useful for humankind in many different ways. The carbon dioxide fixation (at least half of the total) is carried out by algae through photosynthesis; because of photosynthesis, they increase the level of dissolved oxygen in the environment. They are the primary producers in all the aquatic food chains. They are divided into three main classes – Rhodophyceae, Phaeophyceae and Chlorophyceae.

Note: The form and size of the algae vary from colonial form such as Volvox to filamentous form such as Spirogyra. A few of the marine form, they form massive plant bodies such as kelps. Some of the algae are also found in association with fungi (lichen) and other animals for example in sloth bears.