Chp 1 Parasitism And Other Animal Association Flashcards
Question and Options
Answer and Explanation
What percentage of the foods grown and consumed by the rural poor is believed to feed parasitic worms? a) 25% b) 50% c) 75% d) 100%
Answer: b) 50% Explanation: The text states that more than half of the foods grown and consumed by the rural poor go to feed parasitic worms. This highlights the significant impact of parasitism on nutrition among vulnerable populations.
Which region is noted to have higher infection rates of parasites? a) Arctic b) Temperate zones c) Tropics d) Deserts
Answer: c) Tropics Explanation: The text indicates that parasitic diseases are particularly severe in tropical regions, where warmer climates support higher infection rates.
What are the two main categories of parasites mentioned? a) Ectoparasites and Endoparasites b) Microparasites and Macroparasites c) Obligate and Facultative parasites d) Temporary and Permanent parasites
Answer: a) Ectoparasites and Endoparasites Explanation: The text categorizes parasites into ectoparasites, which live on the host’s surface, and endoparasites, which live within the host’s body.
What is the definition of parasitism according to the text? a) A mutually beneficial relationship between species b) An association where one organism harms another c) A relationship where both organisms benefit equally d) A competition for resources
Answer: b) An association where one organism harms another Explanation: Parasitism is defined in the text as an association that involves contact between individuals of different species, where the parasite is metabolically dependent on the host and typically harmful.
What term describes parasites that live on the surface of the host? a) Endoparasites b) Ectoparasites c) Obligate parasites d) Microparasites
Answer: b) Ectoparasites Explanation: Ectoparasites are defined as organisms that live on the surface of hosts, such as ticks and mites.
Which of the following is an example of an endoparasite? a) Tick b) Louse c) Ascaris lumbricoides d) Flea
Answer: c) Ascaris lumbricoides Explanation: Ascaris lumbricoides is a type of roundworm that lives within the body of the host, making it an endoparasite.
Obligate parasites are defined as those that: a) Can live independently of a host b) Depend on a host for part of their life cycle c) Only live on the surface of a host d) Can survive without any host
Answer: b) Depend on a host for part of their life cycle Explanation: Obligate parasites are entirely dependent on their hosts for survival at certain stages of their life cycle.
What distinguishes facultative parasites from obligate parasites? a) Facultative parasites can always cause disease b) Facultative parasites do not require a host c) Facultative parasites live only on the host’s surface d) Facultative parasites are larger than obligate parasites
Answer: b) Facultative parasites do not require a host Explanation: Facultative parasites usually live a free-living existence but can adopt a parasitic lifestyle if necessary, unlike obligate parasites which are completely dependent on their hosts.
What are proliferous parasites? a) Large multicellular organisms b) Microscopic organisms that multiply in the host c) Parasites that require multiple hosts d) Parasites that do not cause disease
Answer: b) Microscopic organisms that multiply in the host Explanation: Proliferous (micro) parasites are defined in the text as microscopic organisms, such as bacteria and protozoans, that can multiply significantly within the human body.
Which of the following is considered a temporary parasite? a) Ascaris lumbricoides b) Ticks c) Liver flukes d) Tapeworms
Answer: b) Ticks Explanation: Temporary parasites, like ticks, only visit their hosts occasionally to feed.
What is a definitive host? a) The host where the parasite lives for its entire life b) The host where sexual reproduction of the parasite occurs c) The host that carries the larval stage of the parasite d) The host that is not necessary for the parasite’s life cycle
Answer: b) The host where sexual reproduction of the parasite occurs Explanation: A definitive host is one where the parasite reaches maturity and reproduces sexually, which is crucial for the parasite’s life cycle.
What is the role of an intermediate host? a) To provide a final habitat for the parasite b) To support the sexual reproduction of the parasite c) To harbor larval or asexual stages of the parasite d) To serve as a permanent residence for the parasite
Answer: c) To harbor larval or asexual stages of the parasite Explanation: The intermediate host is where the larval or asexual stages of the parasite occur, often required for the completion of the life cycle.
Reservoir hosts are significant because they: a) Are the primary hosts for all parasites b) Help in the transmission of parasites to new hosts c) Are usually free of parasites d) Are the definitive hosts for parasites
Answer: b) Help in the transmission of parasites to new hosts Explanation: Reservoir hosts harbor parasites and can transmit them to other susceptible hosts, playing a crucial role in the spread of parasitic infections.
What is one common source of parasitic infections? a) Clean drinking water b) Fresh fruits c) Contaminated soil and water d) Pasteurized milk
Answer: c) Contaminated soil and water Explanation: The text lists contaminated soil and water as significant sources of parasitic infections, highlighting environmental factors in disease transmission.
How can parasites cause damage to their hosts? a) By providing additional nutrients b) By competing with the host for food c) By enhancing the host’s immune response d) By promoting growth in host tissues
Answer: b) By competing with the host for food Explanation: Parasites may compete with their hosts for nutrients, leading to malnutrition and other health issues for the host.
Which of the following is a mechanism by which parasites injure their hosts? a) Direct physical damage b) Providing growth hormones c) Enhancing metabolic rates d) Stimulating immune responses
Answer: a) Direct physical damage Explanation: Parasites can cause direct physical damage to their hosts, leading to various health complications, as mentioned in the text.
What are the main portals of entry for parasites into the body? a) Skin and nails b) Mouth and skin c) Hair follicles d) Respiratory passages
Answer: b) Mouth and skin Explanation: The text mentions several portals of entry, including the mouth and skin, through which parasites can enter the host.
What type of parasite feeds on blood? a) Ectoparasite b) Endoparasite c) Obligate parasite d) Facultative parasite
Answer: a) Ectoparasite Explanation: Ectoparasites, such as mosquitoes and ticks, feed on the blood of their hosts, causing injury and potential disease.
Which parasite is known for causing necrosis of host cells? a) Ascaris b) Plasmodium c) Giardia d) Taenia
Answer: b) Plasmodium Explanation: Plasmodium is responsible for malaria and can cause necrosis in infected host cells, as indicated in the text.
What is the function of toxins released by parasites? a) To aid in nutrient absorption b) To stimulate host cell growth c) To damage host tissues d) To enhance host immunity
Answer: c) To damage host tissues Explanation: Toxins released by parasites can cause tissue damage and contribute to the disease process in the host.
How do parasites generally enter the body through trauma? a) By penetrating through intact skin b) Through inhalation c) Via direct injection d) By ingestion of contaminated food
Answer: a) By penetrating through intact skin Explanation: Certain parasites can enter the body through breaks in the skin or other forms of trauma.
What characterizes accidental parasites? a) They are always harmful to their hosts b) They acquire unusual hosts and survive in them c) They are incapable of causing any harm d) They only infect humans
Answer: b) They acquire unusual hosts and survive in them Explanation: Accidental parasites can infect hosts that are not typically part of their life cycle, allowing them to survive in unusual environments or hosts.
What type of parasite competes with the host for ingested food? a) Ectoparasite b) Macroparasite c) Microparasite d) Temporary parasite
Answer: c) Microparasite Explanation: Microparasites, such as tapeworms and certain protozoa, can absorb nutrients directly from the host’s intestinal contents, thereby competing for food.
What is a characteristic of hyper-parasites? a) They do not harm their hosts b) They infect other parasites c) They are always ectoparasites d) They are larger than their hosts
Answer: b) They infect other parasites Explanation: Hyper-parasites are defined as parasites that infect other parasites, illustrating a complex interaction within the parasitic ecosystem.
What is a primary factor in the definition of a host? a) The host must be a plant b) The host must be capable of independent life c) The host provides nourishment and shelter to the parasite d) The host must be larger than the parasite
Answer: c) The host provides nourishment and shelter to the parasite Explanation: The host is characterized by its ability to provide essential resources, including nutrients and habitat, for the parasite’s survival.
Which type of host is essential for a parasite’s sexual reproduction? a) Reservoir host b) Paratenic host c) Intermediate host d) Definitive host
“Answer: d) Definitive host Explanation: The definitive host is where the sexual reproduction of the parasite occurs and is vital for
Which type of host is essential for a parasite’s sexual reproduction? a) Reservoir host b) Paratenic host c) Intermediate host d) Definitive host
Answer: d) Definitive host\nExplanation: The definitive host is where the sexual reproduction of the parasite occurs and is vital for completing its life cycle.
What distinguishes a paratenic host from an intermediate host? a) It allows full development of the parasite b) It is necessary for the parasite’s life cycle c) It is not necessary for the parasite’s development d) It hosts the adult form of the parasite
Answer: c) It is not necessary for the parasite’s development\nExplanation: A paratenic host serves as a temporary refuge for larval stages of the parasite without being essential for the parasite’s development.
What kind of parasite is Strongyloides stercoralis classified as? a) Microparasite b) Macroparasite c) Obligate parasite d) Facultative parasite
Answer: d) Facultative parasite\nExplanation: Strongyloides stercoralis is classified as a facultative parasite because it can exist independently of a host but can also adopt a parasitic mode of life when necessary.
How can parasitic infections be transmitted from contaminated water sources? a) Through the air b) By direct contact with skin c) By ingestion d) Through inhalation
Answer: c) By ingestion\nExplanation: Ingesting contaminated water containing parasite eggs or cysts is a common route for transmission of parasitic infections.
What is one mechanism by which parasites evade the host’s immune response? a) Enhancing host immunity b) Rapidly changing surface proteins c) Providing nutrients to the host d) Decreasing host metabolism
Answer: b) Rapidly changing surface proteins\nExplanation: Some parasites can evade the immune system by altering their surface proteins, making it difficult for the host to recognize and attack them.
What is a common characteristic of permanent parasites? a) They only live on the host temporarily b) They can survive outside of the host c) They are resident in their hosts for extended periods d) They always cause immediate disease
Answer: c) They are resident in their hosts for extended periods\nExplanation: Permanent parasites live within or on their hosts for prolonged periods, often causing chronic infections.
Which of the following is a potential source of morbidity due to parasites? a) Improved sanitation b) Vaccination programs c) Poor sanitation and unhygienic habits d) Regular medical check-ups
Answer: c) Poor sanitation and unhygienic habits\nExplanation: The text indicates that poor sanitation and unhygienic practices are significant contributors to the incidence of parasitic infections.
What is one way that parasites can induce neoplastic changes in hosts? a) By providing necessary nutrients b) By direct damage to host DNA c) By stimulating immune responses d) By promoting host cell proliferation
Answer: b) By direct damage to host DNA\nExplanation: Certain parasites can directly damage the genetic material of host cells, potentially leading to cancerous growths.
How can parasites cause allergic manifestations? a) By producing toxins b) By inducing immune tolerance c) By irritating host tissues d) By stimulating immune responses to their presence
Answer: d) By stimulating immune responses to their presence\nExplanation: Some parasites can provoke allergic reactions in hosts as the immune system responds to their antigens, leading to various symptoms.
What is a primary way parasites can enter through the skin? a) Inhalation b) Trauma c) Ingestion d) Congenital transmission
Answer: b) Trauma\nExplanation: Parasites can enter the host’s body through trauma, as seen in the case of hookworms and certain other parasites that penetrate the skin.
Which of the following is an example of a non-proliferous parasite? a) Bacteria b) Fungi c) Tapeworm d) Protozoan
Answer: c) Tapeworm\nExplanation: Tapeworms are large, multicellular parasites that do not multiply within the host, thus categorizing them as non-proliferous parasites.
What term describes the relationship between parasites and their hosts? a) Mutualism b) Commensalism c) Parasitism d) Symbiosis
Answer: c) Parasitism\nExplanation: Parasitism specifically refers to a relationship where one organism (the parasite) benefits at the expense of another organism (the host).
Which of the following best describes the term ‘infestation’? a) Presence of parasites within body tissues b) Presence of parasites on the surface of the host c) Absence of parasites in the environment d) Disease caused by bacterial infections
Answer: b) Presence of parasites on the surface of the host\nExplanation: Infestation refers to the presence of ectoparasites on the surface of the host, rather than within body tissues.
What type of parasite is defined as one that primarily lives on the host? a) Endoparasite b) Ectoparasite c) Obligate parasite d) Microparasite
Answer: a) Endoparasite\nExplanation: Endoparasites live within the host’s body, often in internal organs or tissues.
