Problem 83 - Objective Biology for NEET

Question

Match the following: Column I Column II A. Ascaris 1\. Intestinal round worm B. Wuchereria 2\. Filarial worm C. Ancylostoma 3\. Hook worm D. Pheretima 4\. Earth worm (a) \(\mathrm{A}-2, \mathrm{~B}-4, \mathrm{C}-3, \mathrm{D}-1\) (b) \(\mathrm{A}-1, \mathrm{~B}-2, \mathrm{C}-3, \mathrm{D}-4\) (c) \(\mathrm{A}-4, \mathrm{~B}-3, \mathrm{C}-1, \mathrm{D}-2\) (d) \(\mathrm{A}-2, \mathrm{~B}-1, \mathrm{C}-4, \mathrm{D}-3\)

Step-by-Step Solution

Answer

The correct match is (b) A-1, B-2, C-3, D-4.

Step 1: Match 'Ascaris'

Ascaris is a type of parasitic roundworm, more commonly known as an intestinal roundworm. So, A matches with 1.

Step 2: Match 'Wuchereria'

Wuchereria is a type of filarial worm. So, B matches with 2.

Step 3: Match 'Ancylostoma'

Ancylostoma is a genus of hookworms. So, C matches with 3.

Step 4: Match 'Pheretima'

Pheretima is an earthworm. So, D matches with 4.

Key Concepts

Parasitic Worms

Parasitic worms, also known as helminths, are a group of organisms that live on or in a host organism, obtaining nutrients at the host's expense. These worms can cause a variety of infections in animals and humans, often living in the intestines or other body tissues. There are different types of parasitic worms, including:

• Roundworms (nematodes): These are cylindrical, invertebrate animals found in soil, which can infect various parts of the body.
• Tapeworms (cestodes): Ribbon-like worms usually found in the intestines of host animals.
• Flukes (trematodes): Flatworms that can live in the liver, blood, or lungs of their host.

Understanding parasitic worms is critical for managing the illnesses they cause and ensuring better public health.

Earthworm Identification

Identifying earthworms, like Pheretima, involves recognizing their segmented bodies and cylindrical shape. Earthworms are essential for soil health as they aerate the soil and help decompose organic matter, making nutrients more available to plants. Key identifying features include:

• Segmented bodies with a distinct clitellum, which appears as a thicker section of the worm.
• No eyes, but they are sensitive to light through their skin.
• Chaetae, tiny bristles on each segment, help them move through the soil efficiently.

Earthworms play a crucial role in agricultural ecosystems and are considered bioindicators of soil fertility.

Roundworms

Roundworms, or nematodes, are one of the most diverse groups of animals, with many species being parasitic. They have a simple body plan, which includes a cylindrical, elongated shape that is usually tapered at both ends. Roundworms can affect humans and animals, causing diseases like ascariasis and trichinosis. Key characteristics of roundworms include:

• Unsegmented and smooth bodies.
• A flexible but tough outer cuticle.
• A complete digestive system that runs through their entire body.

Due to their resilience and adaptability, they can survive in various environments, from marine to terrestrial habitats.

Filarial Worm

Filarial worms are thin, thread-like nematodes that are responsible for causing filariasis in humans and animals. This disease can lead to chronic conditions like elephantiasis or river blindness if left untreated. They are typically transmitted through mosquito bites, where juvenile worms enter the bloodstream and mature into adults in the lymphatic system.

• Adult filarial worms live in the lymphatics or under the skin.
• They have a complex life cycle involving a host (usually humans) and a vector (mosquitoes).
• Diagnosis of filariasis often involves detecting microfilariae in the blood during specific times when mosquitoes are most active.

Controlling mosquito populations and preventive care are essential for reducing the spread of filarial infections.

Hookworm

Hookworms are a common type of parasitic roundworm that infects humans and animals. They reside in the small intestine, where they attach to the lining and feed on the host's blood, leading to anemia and other health issues. Key facts about hookworms include:

• They are transmitted via contact with contaminated soil, often through bare feet.
• Symptoms of hookworm infection include abdominal pain, diarrhea, and even cognitive impairment in severe cases.
• Hookworm prevention involves wearing shoes and improving sanitation and hygiene.

Education on proper sanitation and the use of protective footwear can significantly lower the risk of hookworm infections, particularly in areas with poor sanitation.