Question

In a pair of copulating earthworms, which two processes take place?
(a) External fertilization and cross fertilization
(b) Cross fertilization and reciprocal fertilization
(c) Internal fertilization and cross fertilization
(d) Reciprocal fertilization and internal fertilization

Answer 1

Hint: A hermaphrodite is an organism that contains partial or complete reproductive organs and can produce gametes for both male and female sexes. Hermaphroditic animals constitute about $5\%$ of all animal species.

Complete Answer:
Earthworms are found around the world where there is soil, water and optimal temperature. Earthworms usually live in soil where they consume organic matter. An earthworm's digestive system comprises its entire body. Earthworms respire through their skin. They have a central nervous system and a peripheral nervous system.
Earthworms are hermaphroditic organisms, i.e an individual earthworm carries both male and female reproductive organs. Earthworms develop their reproductive organs in 60-90 days after birth. Earthworms attain their full size within a year of birth. Earthworm mating occurs at night and at the surface. They are hermaphrodites with their reproductive organs located at segments 9 to 15. Earthworms also have at least one pair of testes located in the sacs. The seminal vesicles produce, store and release the sperms into the duct via the male pores. The ovaries and the oviduct located in the 13th segment release the eggs via the female pores. The female pores are located on the 14th segment.
A pair of copulating earthworms undergo internal fertilization and cross fertilization.

Hence, the correct answer is (c) Internal fertilization and cross fertilization

Note:
An earthworm is an invertebrate that belongs to the phylum Annelida. Earthworms have a tube in a tube body plan. They are externally segmented and have internal segmentation corresponding to the external segmentation. Earthworms usually have setae on all of their segmentations.