Question

Which of the following option shows bisexual animals only?
(a) Amoeba, sponge, leech
(b) Sponge, cockroach, amoeba
(c) Earthworm, sponge, leech
(d) Tapeworm, earthworm, honeybee

Answer 1

Hint: Bisexual animals are those who have both sex organ presents inside a single individual. Even the gametes they produce are associated with both male and female sexes.

Complete step by step answer:
Bisexual animals or hermaphrodites are different from unisexual animals, in the fact that they possess both male and female sex organs in a single individual. Bisexual nature is seen mostly in angiosperm plants but some animals own both the sex organs and also their gametes associate with both male and female sexes. Examples of such animals are the earthworm, tapeworm, sponge, leech, etc.
So, the correct answer to the question is earthworm, sponge, and leech.

Additional information:
A unisexual organism has either male or female sexes whereas bisexual organisms can possess both the sexes in one organism. Bisexual nature is seen in plants where the flower of such plants contains both male and female reproductive structures I.e. both carpel and stamen. In animals, very few of them can possess a hermaphrodite nature. These animals have both male and female sexual organs and can produce both male and female gametes. Let's take some examples of such animals and see their process of reproduction:
- Earthworm: In earthworm, the male and female sex organs produce sperm and egg respectively in each individual. After that, the two earthworms mate and exchange sperm. The fertilized egg develops later on and produces new worms.
- Leech: In the case of leeches, the two sex organs are not active at the same time. They find partners and mate and fertilization takes place in the female part.
- Tapeworm: Each segment of tapeworm has two sets of male and female reproductive organs that fill with fertile eggs and the segment is pushed back from the neck. When it gets filled, it detaches and passes in the feces.
- Sponge: Sponges carries out both sexual and asexual reproduction. Asexual by budding and in case of sexual one sponges produce eggs and sperms.

Note: Earthworm, leech, and sponge have both male and female organs, so they are called bisexual or hermaphrodite. Although other options in the question also contain one or two bisexual organisms, in the other three options there’s at least one unisexual organism.