Question

Which of the following characteristics is common in leech, mosquito, bedbug, and rat?
A. All have anticoagulation
B. All have RNAs as their genetic material
C. All have no cell membrane
D. All have a sexual phase

Answer 1

Hint: Leech belongs to phylum Annelida, mosquito, bed bug belong to Phylum Arthropoda while rats belong to class Mammalia.

Complete Answer:
Let us analyse each given option to find out the correct answer.
Option A: Leeches belonging to the phylum Annelida produce an enzyme in their saliva called hirudin. Hirudin is a powerful anticoagulant. Leeches produce hirudin to prevent their host from forming a clot so that they can feed on blood more easily. The anticoagulant formation is not seen in mosquitoes, bedbugs, and rats. Therefore, this is an incorrect option.

Option B: Ribonucleic acid (RNA) is a molecule similar to DNA. Unlike DNA, RNA is single-stranded. The primary role of RNA is to convert the information stored in DNA into proteins. However, RNAs can be genetic material in some viruses. RNAs are present in all animals but they do not act as genetic material. In leech, mosquito, bedbug, and rat, DNA is the genetic material. Therefore, this is an incorrect option.

Option C: Cell membrane is the semipermeable membrane of a cell that surrounds and encloses its contents of cytoplasm and nucleoplasm. All animal cells possess a plasma membrane or cell membrane and contain a membrane-bound nucleus and organelles. Therefore, this is an incorrect option.

Option D: Leeches are hermaphrodites. In some of the leech species, younger adults function as males and become females at maturity. All have well-developed gonads and copulate. Mosquito also undergoes several sexual phases and gets transformed into various different forms. The male bed bug can inseminate the female and have sexual phases in their life cycle. Rats reproduce sexually and have a sexual phase. Therefore, this is the correct option.

Thus, the correct option is D All have a sexual phase.

Note: It is to be noted that hermaphrodite animals are those that have both male and female genitalia. In all the animals, male and female gametes are present. On fusion of male and female gametes, a zygote is formed which gives rise to a new offspring.