Exam 1 Flashcards
Describe the concept of animal associations
Parasitism deals with animal association. How species interact with each other.
What is parasitism?
A symbiotic relationship between two organisms: A parasite usually the smaller of the two, and a host, upon which the parasite is physiologically dependent. This relationship may be permanent. Example: When ticks and mosquitos feed on the host blood.
Describe the concept of symbiosis
- Close association of organisms of different species.
- An organism that spends a portion or all of its life intimately associated with another living organism of a different species without any benefit or damage
What did Eugene Odum study?
Affects on population growth
What is commensalism? +/-
- One partner benefits and the other has no effect
Does not involve dependency between the two partners: the host and the commensal. Spatial proximity allows the commensal to feed on substances captured. The 2 partners can survive independently. For example: The association of hermit crabs and the sea anemones they carry on their borrowed shells.
What is phoresis?
- 2 symbionts brawl together
- The human botfly lays their eggs on the mosquito and eggs hatch when the mosquito has a blood meal. Then the mosquito gets no effect and the botfly benefits.
The smaller organism is mechanically carried by the other larger organism which is the host. Unlike commensalism, there is no dependency in the procurement of food by either partner. Example: The numerous fungi, algae, and protozoans that attach to the bodies of aquatic anthropoids like turtles.
What is mutualism?
- Obligatory physiological independence
- Termites ingest wood and digest into intestinal protists. One would die without the other
- An association in which the mutualist and the host depend on each other physiologically. Example: Protozoans and termites and whose gut they live. They need each other to survive.
Name 4 types of attackers for exploitation relationships
- Predator
- Parasitoid
- Micropredator
- Parasite
What is a predator?
An animal that naturally preys on others
What is a parasitoid?
An insect (e.g., the ichneumon wasp) whose larvae live as parasites that eventually kill their hosts (typically other insects).Like a parasite, a parasitoid infects just one host per life stage. But parasitoids always kill their hosts. Only one organism is attacked and killed. - A female wasp deports eggs on another insect and when they hatch, they kill the host
What is a micropredator?
An organism,e.g., the mosquito, that derives elements essential for its existence from other species of organisms, larger than itself, without causing their destruction.
What is a parasite?
- Lives in or on a host
- Has greater reproductive potential than its host
- Gets nutrients from its host
- Has the potential of harming the host
Generally, what is parasitism?
An organism that lives in or on another organism (its host) and benefits by deriving nutrients at the host’s expense .
What organisms are parasites?
A few examples of parasites are tapeworms, fleas, and barnacles. Tapeworms are segmented flatworms that attach themselves to the insides of the intestines of animals such as cows, pigs, and humans. They get food by eating the host’s partly digested food, depriving the host of nutrients.
What are the 3 types of parasites?
- Helminths- A parasitic worm; a fluke, tapeworm, or nematode.
- Protozoa- Single-celled organisms with animal-like behaviors, such as motility and predation.
- Arthropods- an invertebrate animal of the large phylum Arthropoda, such as an insect, spider, or crustacean.
What are NOT parasites?
- bacteria
- viruses
- fungi
Name the 4 types a parasites
- Ectoparasite- On host’s surface outside such as ticks
- Endoparasite- lives inside a host
- Obligate- Must be parasite for at least part of its life cycle
- Facultative- Does not normally have parasitic opportunity. Is an organism that may resort to parasitic activity, but does not absolutely rely on any host for completion of its life cycle
Name 2 types of hosts
- Definitive host (DH)- An organism that supports the adult or sexually reproductive form of a parasite
- Intermediate host (IH)- An organism that supports the immature or non reproductive forms of a parasite. Absolutely required for parasite development and does not reach sexual maturity
What does over-dispersion mean?
Negative binomial. Too many parasites inside the host.
What are the 2 types of life cycles a parasite can take into its host?
- Direct- Parasite passed from one definitive host to the next definitive host through air OR by a famite with food and water
- Indirect- Goes through an intermediate host
For each of the following, identify whether it could be a parasite according to the traditional definition.
cestode-
trematode-
bacteria-
nematode-
virus-
fungus-
protozoan-
arthropod-cestode- YES
trematode- YES
bacteria- NO
nematode- YES
virus- NO
fungus- NO
protozoan- YES
arthropod- YESReading Question: Explain the differences between the 4 categories of symbiotic relationships.
- Commensalism- Does not involve dependency between the two partners: the host and the commensal. Spatial proximity allows the commensal to feed on substances captured. The 2 partners can survive independently. For example: The association of hermit crabs and the sea anemones they carry on their borrowed shells.
- Phoresis- The smaller organism is mechanically carried by the other larger organism which is the host. Unlike commensalism, there is no dependency in the procurement of food by either partner. Example: The numerous fungi, algae, and protozoans that attach to the bodies of aquatic anthropoids like turtles.
- Parasitism- A symbiotic relationship between two organisms: A parasite usually the smaller of the two, and a host, upon which the parasite is physiologically dependent. This relationship may be permanent. Example: When tick and mosquito feed on the host blood.
- Mutualism- An association in which the mutualist and the host depend on each other physiologically. Example: Protozoans and termites and whose gut they live. They need each other to survive.
Reading Question: What is a zoonosis?
- A disease of humans that is caused by a pathogenic parasite normally found in wild and domestic vertebrate animals
Reading Question: Describe the symbiotic relationship which occurs between termites and the flagellated protozoans which inhabit their gut
The flagellate depends on a carbohydrate diet and acquires nutrients from wood ingested by the termite. In return, the flagellate synthesizes and secretes cellulose so which the termite utilizes. They would die without each other and have a mutualist if relationship.
Sample Question
Which of the following is always physiologically dependent on the relationship with its symbiotic partner?
A. phoront
B. commensal
C. host
D. symbiont
E. parasiteE. parasite
Sample Question
Most parasite populations are overdispersed in their host population. This means that
A. most hosts who are infected produce fewer offspring than uninfected individuals
B. most hosts harbor few parasites, while a few hosts are infected with many
parasites
C. all of the hosts harbor approximately the same number of parasites
D. most hosts are infected with many parasites, while a few hosts harbor only a
small number of parasites
E. there is no relationship between hosts and the number of parasites they harbor
B. most hosts harbor few parasites, while a few hosts are infected with many
parasites
What are the leading causes of death in US?
The leading cause of death in the U.S. from the CDC is heart disease, cancer, stroke, lower respiratory disease, accidents, and diabetes
What are the leading causes of death in underdeveloped countries?
Heart disease, lower respiratory infections, HIV, diarrheal diseases with bacteria and parasites, malaria, TB
What are the United Nations?
2000 people called a plan for sustainable development and eradication of poverty in underdeveloped countries and call the millennium development goals. The due date for these goals was 2015
Name as many Millennium Development Goals (MDGs) as you can
- Radicate extreme poverty and hunger
- Achieve universal primary education
- Promote gender equality
- Reduce child mortality
- Improve maternal health
- To combat HIV/Malaria and other diseases
- Ensure environmental sustainability
- Development of global partnership
What was the “Big Three?”
- HIV medications
- Tuberculosis antibiotics
- Malaria drugs
What are NTD’s?
Neglected Tropical Diseases (NTDs)- A group of 17 diseases
Name four helminths
- Foodborne trematodiases
- Schistosomiasis- Caused by the parasitic fluke
- Cysticercosis/Taeniasis- Food worm infection
- Echinococcosis- Parasitic disease of tapeworms
- Soil-transmitted helminths (STH)- Caused specifically by those helminths which are transmitted through soil contaminated with fecal matter
Name some examples of foodborne trematodiases cause by helminths
- Clonorchiasis- Is an infectious disease caused by the Chinese liver fluke, Clonorchis sinensis
- Fascioliasis- Infestation of a human or an animal with the liver fluke
- Opisthorchiasis- Infection of the biliary tract by the liver flukes
- Paragonimiasis- Infestation with or disease caused by a lung fluke
What are examples of soil-transmitted helminths (STH)?
- Ascariasis- 4.2 billion people are at risk. Infection in the intestine.
- Hookworm Infections- A parasitic nematode worm that inhabits the intestines of humans and other animals. It has hooklike mouthparts with which it attaches itself to the wall of the gut, puncturing the blood vessels and feeding on the blood.
- Trichiuriasis- 60 million people are at risk. A disease caused from infected meat, especially pork, characterized by digestive disturbance, fever, and muscular rigidity.
What is Lymphatic Filariasis?
A helminth. Parasitic disease caused by microscopic, thread-like worms. The adult worms only live in the human lymph system
What is Onchocerciasis (river blindness)?
A helminth. 90 million people at risk. Disease caused by filarial worms. Causes impaired vision.
What is Dracunculiasis (guinea-worm disease)?
A helminth. Is an infection by the guinea worm. A person becomes infected when they drink water that contains water fleas
What are NTD’s caused by?
- Helminths
- Protozoans
- Bacteria
- Viruses
What NTD’s do protozoans cause?
- Human African trypanosomiasis (sleeping sickness)- 60 million people infected. A parasitic disease transmitted by the bite of the ‘Glossina’ insect.
- Chagas disease- A disease caused by trypanosomes transmitted by bloodsucking bugs. Affects the heart and nervous system.
- Leishmaniases- A tropical and subtropical disease caused by leishmania and transmitted by the bite of sandflies
What NTD’s do bacteria cause?
- Buruli ulcer – Mycobacterium ulcerans- Where skin and bone get destroyed
- Leprosy – Mycobacterium leprae - Affects the peripheral nerves and skin with 250,000 people at risk
- Trachoma – Chlamydia trachomatis- A contagious bacterial infection of the eye in which there is inflamed granulation on the inner surface of the lids.
- Yaws - Treponema pallidum subspecies pertenue- Related to syphilis and is not sexually transmitted. Affects the skin, bone, and cartilage
What NTD’s do viruses cause?
- Dengue/Severe dengue- Fever, headache, and small # of cases, hemoragic fever
- Rabies- Kills in Asia and Africa and causes 60,000 deaths. A contagious and fatal viral disease of dogs and other mammals that causes madness and convulsions, transmissible through the saliva to humans.
What are some features of NTD’s?
Are a diverse group of diseases with distinct characteristics that thrive mainly among the poorest populations. The 17 NTDs prioritized by WHO are endemic in 149 countries and affect more than 1.4 billion people, costing developing economies billions of dollars every year.
What is the bottom billion?
We have 7 billion people and the bottom billion is 1.4 billion and they live on less than $1.24 a day. 50% of the world’s population live on $2 a day
Describe the equation for Disability-adjusted life years (DALYs)
# of healthy years lost due to disability and premature death. DALY- YLL (years life lost) + YLD (years lived with disability) - Japanese life expectancy is used so we can make comparison between diseases
What are some control strategies for NTD’s ?
- Rapid Impact Packages - 4 drugs targeting 7 diseases for less than 50 cents per year. a blister pack of pills. There are 4 drugs in a pack. They were brought to Africa, Asia, and South America.
- Helen Keller International- To get the drugs to the people with the Hellen Keller International Organization
