Chpt 6a Insects Of Medical Importance Flashcards
- Which of these is NOT a characteristic of insects? a) They belong to the phylum Arthropoda. b) They are bilaterally symmetrical. c) They have an open circulatory system with haemolymph. d) They have four pairs of wings.
Answer: d) They have four pairs of wings. Explanation: Insects have three pairs of legs and generally one or two pairs of wings.
- Which of the following insects is responsible for the transmission of trypanosomiasis? a) Butterflies b) Tsetse flies c) Bees d) Moths
Answer: b) Tsetse flies Explanation: Tsetse flies are vectors of trypanosomiasis also known as sleeping sickness.
- Which of these is a characteristic of chewing lice? a) They have sucking mouth parts. b) They feed on feathers or hair. c) They are major vectors of human diseases. d) They have piercing and sucking mouth parts.
Answer: b) They feed on feathers or hair. Explanation: Chewing lice feed on feathers or hair and are sometimes referred to as chewing lice.
- Pediculus humanus is commonly known as: a) Chewing louse b) Head louse c) Pubic louse d) Body louse
Answer: b) Head louse Explanation: Pediculus humanus is the scientific name for the human head louse.
- How long does the egg stage of the head louse typically last? a) 1-2 days b) 3-4 days c) 6-9 days d) 10-12 days
Answer: c) 6-9 days Explanation: The text states that eggs hatch in 6-9 days depending on temperature.
- Which disease is caused by Rickettsia prowazekii and transmitted by lice? a) Relapsing fever b) Typhus c) Trench fever d) Scabies
Answer: b) Typhus Explanation: The text states that typhus is caused by a rickettsial organism Rickettsia prowazekii.
- Which of these is a symptom of pediculosis? a) High fever b) Severe itching c) Hair loss d) Skin discoloration
Answer: b) Severe itching Explanation: Pediculosis an infestation with lice results in irritability lousy feeling dermatitis or severe itching.
- Where on the human body is Pthirus pubis typically found? a) Head b) Pubic region c) Armpits d) Feet
Answer: b) Pubic region Explanation: The pubic louse (Pthirus pubis) is typically found in the hairs of the pubic region.
- Which of these is NOT a control measure for pubic lice? a) Shaving of pubic hair b) Use of insecticides c) Washing hair with hot water d) Taking antibiotics
Answer: d) Taking antibiotics Explanation: Antibiotics are not effective against lice. Control methods include shaving pubic hair using insecticides and washing hair with hot water.
- What type of mouth parts do bed bugs possess? a) Chewing b) Piercing and sucking c) Siphoning d) Sponging
Answer: b) Piercing and suckingExplanation: The text states that Hemipterans have sucking mouthparts. Bed bugs belong to the order Hemiptera.
- Which of the following diseases is NOT transmitted by fleas? a) Plague b) Typhus c) Tapeworm d) Malaria
Answer: d) Malaria Explanation: Malaria is transmitted by mosquitoes not fleas.
- Which bacteria is responsible for causing plague? a) Rickettsia typhi b) Yersinia pestis c) Bartonella quintana d) Borrelia recurrentis
Answer: b) Yersinia pestis Explanation: The text states that plague is transmitted by Xenopsylla cheopis and Pulex irritans. Both of these fleas pick up the bacterium Yersinia pestis during a blood meal.
- Which flea species is the primary vector for the transmission of plague? a) Ctenocephalides canis b) Ctenocephalides felis c) Pulex irritans d) Xenopsylla cheopis
Answer: d) Xenopsylla cheopis Explanation: The text states that plague which is primarily a zoonosis is transmitted mainly by Xenopsylla cheopis.
- What is the major intermediate host for flea-borne typhus? a) Pulex irritans b) Ctenocephalides canis c) Xenopsylla cheopis d) Tunga penetrans
Answer: c) Xenopsylla cheopis Explanation: The major intermediate host for flea-borne typhus is Xenopsylla cheopis but other fleas can also be involved.
- Where do sand-flies typically lay their eggs? a) On the surface of water b) In the fur of animals c) In crevices burrows tree holes d) On plants
Answer: c) In crevices burrows tree holes Explanation: Females lay eggs in crevices burrows tree holes and other places with high humidity and debris.
- What type of mouth parts do sand-flies possess? a) Piercing and sucking b) Chewing c) Sponging d) Siphoning
Answer: a) Piercing and sucking Explanation: Sand-flies have sucking mouthparts. They have brownish hairy mouthparts.
- Which of these diseases is NOT transmitted by sand-flies? a) Sand fly fever b) Leishmaniasis c) Bartonellosis d) Plague
Answer: d) PlagueExplanation: Plague is transmitted by fleas not sandflies.
- What is the causative agent of leishmaniasis? a) A bacteria b) A virus c) A protozoan d) A helminth
Answer: c) A protozoan Explanation: Leishmaniasis is a protozoan disease caused by a flagellate Leishmania.
- Which form of Leishmania is found in the sandfly? a) Amastigote b) Promastigote c) Epimastigote d) Trypomastigote
Answer: b) Promastigote Explanation: The sandfly bite injects promastigotes into a new host.
- Which of these is a symptom of visceral leishmaniasis? a) Skin lesions b) Enlarged spleen c) Hair loss d) Fever and chills
Answer: b) Enlarged spleen Explanation: Visceral leishmaniasis affects the internal organs e.g. liver spleen and bone marrow.
- Where in the human body does the Onchocerca volvulus reside? a) Blood vessels b) Lymphatic system c) Intestines d) Subcutaneous tissues
Answer: d) Subcutaneous tissues Explanation: Adult female O. volvulus are found in subcutaneous tissues of man either free or in nodules.
- How long does it take for Onchocerca volvulus to reach adult stage? a) 1-2 months b) 3-6 months c) 6-12 months d) 12-18 months
Answer: d) 12-18 monthsExplanation: The period from infection to production of microfilariae by the female is between 12 months to reach adult stage.
- Which of these is a symptom of onchocerciasis? a) Fever b) Blindness c) Paralysis d) Swelling of the liver
Answer: b) Blindness Explanation: Onchocerciasis is also known as river blindness.
- What are the tiny air tubes that make up the respiratory system in insects called? a) Spiracles b) Tracheae c) Malpighian tubules d) Haemolymph
Answer: b) Tracheae Explanation: Insects breathe using a tracheal system composed basically of a dorsally placed heart which pumps blood posteriorly by means of an open tracheal system with openings to the outside known as spiracles.
- Which of these insect orders is characterized by having two wings? a) Coleoptera b) Diptera c) Hymenoptera d) Lepidoptera Answer: b) Diptera
Explanation: Diptera which means ‘two wings’ includes insects like mosquitos and flies.
- What is the term for the hard protective outer covering found in insects? a) Exoskeleton b) Endoskeleton c) Cuticle d) Carapace
Answer: a) Exoskeleton Explanation: Insects have a hard exoskeleton composed of chitin.
- Which insect order is known for its social behavior and includes ants and bees? a) Isoptera b) Hymenoptera c) Orthoptera d) Hemiptera
Answer: b) Hymenoptera Explanation: Hymenoptera include bees wasps and ants.
- What is the name of the fluid that circulates in an insect’s open circulatory system? a) Blood b) Lymph c) Haemolymph d) Plasma
Answer: c) HaemolymphExplanation: Insects have an open circulatory system containing haemolymph.
. Which of these insects is known for its ability to jump long distances? a) Grasshopper b) Butterfly c) Flea d) Beetle
Answer: c) Flea Explanation: Fleas are well-known for their jumping ability. They have powerful legs with enlarged coxae for jumping.
- Which insect order is known for having scales on their wings? a) Lepidoptera b) Coleoptera c) Diptera d) Hemiptera
Answer: a) Lepidoptera Explanation: Lepidoptera include butterflies and moths which are known for their scaled wings.
- What is the name of the specialized mouthparts found in butterflies and moths used for feeding on nectar?
Answer: Proboscis.
- What is the term for the developmental stage in some insects where they undergo a complete transformation including a pupal stage?
Answer: Complete metamorphosis.