Question

The embryonated egg of Ascaris represents

• A. an egg with blastula
• B. an egg with a juvenile
• C. an egg with an egg
• D. an egg with gastrula.

Answer 1

The Correct Option is B

To determine what the embryonated egg of Ascaris represents, we need to understand the basic biology of Ascaris, which is a type of parasitic roundworm.

Explanation:

Ascaris is a genus of parasitic nematodes known for causing the disease ascariasis in humans. The life cycle of Ascaris involves several key stages, including egg, larval, and adult stages. The embryonated egg is an important part of this cycle, particularly in the transmission of the parasite.

Embryonated Egg of Ascaris:

• The eggs of Ascaris are laid by the female worm and are initially unembryonated.
• The eggs are released into the environment through the feces of the host.
• Under favorable conditions, the eggs become embryonated, which means that they develop within the shell into a larva or juvenile stage.

This development into a larval stage within the egg shell makes the egg infectious. When ingested by a suitable host, the juvenile worm hatches from the egg and continues its life cycle within the new host.

Option Analysis:

• An egg with blastula: This refers to an early stage in the development of many animals but does not apply here.
• An egg with a juvenile: Correct. The embryonated egg of Ascaris contains a juvenile or larval stage inside it.
• An egg with an egg: Illogical in this context, as it does not describe an embryonated stage.
• An egg with gastrula: This term also refers to an early developmental stage in animals, typically not referenced this way for nematodes.

Conclusion:

The correct answer is "an egg with a juvenile," as this accurately describes the embryonated egg of Ascaris, which contains a larval stage ready to hatch when ingested by a host.