CBSE Questions for Class 12 Medical Biology Human Health And Disease Quiz 2 - MCQExams.com

Snails are garden pests, which mostly eat old rotting plants, plant seedlings, leafy vegetables and fruits that grow at ground level. The parts of the plants eaten by snails usually have a ragged hole look. Glomus, earthworm and Oscillatoria are used in organic farming either as a biofertilizer or to improve the quality of the compost. Snails are not used in organic farming.

Therefore, the correct answer is option A.

Enterobius infection or Pinworm infection is primarily a pediatric condition and parents are typically infected via transmission through their children. It is most prevalent in temperate regions of the world. Pinworm infection is spread by the fecal-oral route

So, the correct answer is 'Contamination'

Each adult female worm produces egg or ova are passed out in the faeces. When worms are ingested by humans (through food, water, hands contaminated with faeces), the larva is released into the small intestine, which penetrates the intestinal wall and migrates through the blood stream or via lymphatics to the heart and lungs. The larvae reach the lungs in about 4 days, where they mature within the alveoli in approximately 10 days. They then pass up via bronchi and the trachea, subsequently return to the small intestine (last moult). Again they release out the worm through faeces. On re-entering the intestine, they mature into adult worms. Thus, the correct answer is option D.

• Leech is an Annelid and has a well-developed coelom. 
• Liver fluke is a Platyhelminthes and is the acoelomate animal. 
• Hookworm is Ancylostoma, it is an Aschelminthes animal and is pseudocoelomate as their body cavity is pseudocoelom (fluid filled body cavity present in between the mesoderm and ectoderm). 
• Jellyfish is a Coelenterate animal and is acoelomate. 

• Filariform is the infective third-stage larva of the hookworm, Ascaris, and other nematodes.
• Ascaris belongs to the phylum Aschelminthes.

• Filariasis is caused by Wuchereria bancrofti (the filaria worm) that inhabit the lymphatic vessels. Wuchereria bancrofti is a thread-like filarial nematode (roundworm) and belongs to helminths. 
• Viruses are acellular obligate parasites while bacteria are prokaryotes. 
• Protozoans are eukaryotic unicellular organisms while Wuchereria is a multicellular eukaryote with organ system level body organization. 

• Hemp is a commonly used term for high-growing varieties of the Cannabis sativa plant and its products, which include fiber, oil, and seed. 
• Hemp is refined into products, such as hemp seed foods, hemp oil, wax, resin, rope, cloth, pulp, paper, and fuel. 
• Items ranging from rope to fabrics, to industrial materials were made from hemp fiber. Hemp was often used to make sail canvas, and the word canvas derives from cannabis. 

• An antigen is any substance that causes the immune system to produce antibodies against it. An antigen may be a foreign substance from the environment, such as chemicals, viruses, bacteria, or pollen.
• An antibody is used by the immune system to identify and neutralize foreign antigen, like bacteria.
• Mutagen is a physical or chemical agent, that changes the genetic material of an organism and increases the frequency of mutation.
• A carcinogen is a substance capable of causing cancer in living tissues.