Question

External fertilization occurs in majority of
A) Algae
B) Fungi
C) Liverworts
D) Mosses

Answer 1

The external fertilization occurs when an organism fertilised outside the body. The process of external fertilization usually requires a water body. Here, both the eggs and sperms are released into the water. The majority of external fertilization occurs during spawning. In the spawning, both males and females release a large number of gametes in the external environment. This reproduction process is influenced by sunlight and temperature.

Complete step by step answer:
The benefits of performing external fertilization in an aquatic body are that the eggs do not dry up. The spawning of eggs and sperms in external fertilization leads to greater biodiversity along with higher chances of genetic survival.
-Algae: Fertilization in algae occurs when a male spermatium, carried by water currents, collides with the extended portion of female carpogonium, and two gametes fuse. Algae reproduce by external fertilization.
-Fungi: In many fungi, fertilization is a two-step process. Fertilization of sperm in a single step with the fusion of gametes as in the animal and plants. Internal fertilization is characterized by the sperm of the fertilizing egg within the female. The second step of fertilization is karyogamy.
-Liverworts: In sexual reproduction, liverworts develop umbrella-shaped structure both male and female. Sperm released from the male umbrella swim along with the plants moist surface and fertilize the egg. Liverworts also reproduce asexually.
Mosses: Mosses have gemmae cups on the top that produce which helps in asexual reproduction. In mosses, asexual reproduction also takes place by fragmentation.
External fertilization occurs mostly in wet environments and requires both the female and male to release their heads into the surrounding. An advantage of external fertilization is that it results in the production of a large number of offspring. One disadvantage is that environmental hazards such as predictors greatly reduce the chance of surviving into adulthood. Amphibians and fish aquatic Algae are the examples of animals that reproduce in this way.
Thus, the answer is option A: Algae

Note: The aquatic animals generally release their gametes directly into the environment. It mostly takes place in the fishes and amphibians. Disruptive external fertilization examples are that of the salmon, trout fish, and codfish. Both females and male release their eggs and sperm respectively into the water where they diffuse and fertilize.