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10

I can think of several (non-exclusive and non-exhaustive) hypotheses: It is maladaptive. Because it is a new virus coming from another species or because it is not adapted to our modern lifespan. Some might benefit from host immune defense (sneezing helps bacteria to spread) and death is a consequence of the selection for increasing disease symptomes to ...


7

Yes it is possible to culture plasmodia but they don't grow in a simple constituted medium. Usually RPMI supplemented with serum and erythrocytes is used for growing plasmodia ex-vivo. This article discusses the issues related to plasmodial culture in detail. The authors say that sometimes a certain growth stage (in particular gametocyte) is lost on ...


6

Is consumption of blood more "dangerous" compared to meat? Actually yes, a simple high dose of blood is enough to kill. The cause is, though it is most important thing to live when flowing the vessel, it's highly toxic when consumed. There are high chances of getting haemochromatosis or Iron overload. Source and More on this: ...


6

Plasmodium falciparum (the main causative agent of malaria) and other Plasmodium species have a very complex life cycle, with stages in the female host Anopheles mosquito, in the human liver, and in the human circulatory system, where it primarily resides in the erythrocytes (red blood cells, or RBCs): During a blood meal, a malaria-infected mosquito ...


6

I'll give it a shot, but note that I'm not entirely certain: It's a juvenile bed bug, first stage larva. The size description and the general habitus fit, as well as the white color.


5

The species of wasp you're referring to is Glyptapanteles. I'm not sure which virus it is. http://www.newscientist.com/article/dn14053-zombie-caterpillars-controlled-by-voodoo-wasps.html?feedId=online-news_rss20 Is it possible? Of course, you have an example! Though, there is a small caveat. Some of the offspring sacrifice themselves to induce the ...


5

You're right in saying that yeast is single celled. However, moulds are described to be filamentous fungi that are multicellular. The filaments of the mould give colonies "a woolly, fluffy, or velvety appearance, sometimes punctuated with a granular or powdery aspect that is produced by the formation of asexual reproductive structures"(1). Aspergillus is ...


5

This is a really old thread but just in case someone happens upon it, this isn't a bed bug. I am not an expert but it looks like it's likely a book louse or psocid. See comparison photos of unfed first instar bed bug nymphs vs. psocids/booklice here: http://bedbugger.com/2008/03/04/booklice/ It's all about the shape of the head and body.


4

As Armatus pointed out above, all viruses are obligately intracellular, and their medical and economic importance cannot be overstated. Many bacterial species live intracellularly. The arthropod specific Wolbachia has a wide variety of consequences for its host, including alteration of reproduction and sex ratios, induction of reproductive isolation ...


4

If you have or can get access to it, you might try looking in the Incidence and Prevalence database: http://thomsonreuters.com/incidence-and-prevalence-database/ Another possibility is the GIDEON database: http://www.gideononline.com/. It is possible to sign up for a 15-day trial. For Europe, statistics are available from the WHO CISID at ...


4

The fungus releases toxins, but how exactly this alters behavior is unclear. You can read more here. Pathogen manipulation of host behavior appears to have evolved a long time ago, and cordyceps is not the only pathogen that acts like this.


4

Based on my course material, I managed to get the following list: Malaria - Plasmodium falciparum, p. malariae, p. vivax, p. ovale - female anopheline mosquito Babesiosis - Babesia devergens, babesia microti - tick ixodes ricinus Balantidiasis - Balantidium coli - waterborne Coccidiosis & toxoplasmosis - Eimeria species - waterborne Toxoplasmosis - ...


3

Drosophila is seen as a highly alcohol tolerant species which is mainly dependent on the environment it lives in. So are flies, which are captured in the cellar of a wine yard more tolerant to alcohol than flies which are captured outside (see first reference). The environment in which the flies grow up and live does not influence the activity of the ...


3

All research on saliva tests I've found involve antibody detection which, as you suspected, can produce false negatives depending on the disease process or the presence of immune disfunction (such as due to AIDS). Thus, if you can isolate T. gondii gDNA from the saliva, a genetic assay may be more sensitive. However, Amato Neto et al. report: In 26 ...


3

In model fungi, the G protein coupled receptor Gpr1 is known to sense sugars and upregulate a cAMP linked PKA pathway, while in pathogenic strains, it senses Methionine. This probably is the environmental cue that sets off fruiting. There is a recently published extensive review too: Heterotrimeric G protein signaling in filamentous fungi Reference Li, ...


3

Some parasites aren't natural hosts of humans, instead we are an accidental host in which they cannot replicate. Zoonoses such as this can be quite fatal as the parasite is not adapted to us. Although viruses are often separated, they are parasites and you can see just in influenza that the animal derived flus are more fatal than those that are well adapted ...


3

Oddly enough it is a bit difficult to find good field studies where the diet of spiders was studied. I have a feeling it's a hard thing to get funding for. Luckily some do exist. Peucetia viridans has been shown to eat from the Chrysididae family and Lepidoptera order, but I didn't find an explicit statement that it ate the larvae out of the caterpillar. ...


2

This is related to Remi.b's answer, but a common reason is that sometimes parasites/pathogens actually need to kill the host to spread. A lot of viruses, in particular phages, are only released from their host by bursting out of the cell. If the parasite can't leave the host, there's no point in any of it, and death may be a good way to achieve that. A ...


2

First part of the answer - Yes fleas (Siphonaptera) can be drowned. But not as easily as the internet would lead you to believe. There are many claims on the internet (and printed works) expounding on how simple it is to drown fleas. The best science I found so far on the topic is in Forensic Entomology: An Introduction By Dorothy Gennard; John Wiley & ...


2

Extension of Question Beef tapeworm or Taenia saginata Beef tapeworm or Taenia saginata shows both asexual and sexual reproduction. As you have mentioned if any other partner is not available then it will carry on asexual reproduction. Now, Scolex or the hook attahes to the host. Scolex reproduce asexually by budding. One tapeworm segment or ...


2

Here are some examples: symbiosis between genetic modified yeast cell populations (Shou W et al. 2007) symbiosis between green algae and embryonic chick connective tissue (Buchsbaum R et al. 1934) symbiosis between EcoBot II and microbial fuel cells (Ieropoulos, Ioannis, et al. 2005)


2

Basically, Giarda is a an Excavates while Trichomonas is a Cercozoa meaning a Rhizaria (Chromealveolates in the broad sense as noticed by @har-wradim in the comments (now deleted) because Cercozoa are neither Chromista nor alveolata). Because the very basis of the tree of eukaryotes is still unresolved (eukaryotes), the most recent common ancestor of these ...


1

Children generally don't care about their hair as much as adults do. So unless parents insist, they don't care for their hair as much (reference). Kids generally get lice because they are in close contact with each other during play-dates, slumber parties, and sports activities. They are also prone to exchange hair brushes and other personal items more often ...


1

Taenia solium is more dangerous: T. saginata is relatively innocuous, since only the intestinal tapeworm phase occurs in man, whereas infection with T. solium has major health effects due to extraintestinal infection by the larval or cyst phase in the CNS [1]. The most feared complication of Taenia solium is cysticercosis. Taenia saginata can lead in ...


1

This question has a related issue that should be addressed first: what is a species? To some extent, if you want to understand how speciation can occur, then you have to consider how you are going to define a species. There is no species concept that applies to all species, past or present. The most widely applied concept is the biological species concept ...


1

Do not forget domesticated animals that we now keep as pets. It's not unreasonable to argue that the relationship between dogs/cats and humans has a symbiotic character. The pet gets foodand shelter whereas the owner benefits in other ways, e.g. companionship, deterrence of enemies, herding,...


1

An addition to the answer by Chris. Probably the most dangerous tapeworms for humans are Echinococcus. In humans they form cysts (in a variety of organs including brain) [it's because humans are "interpreted" as intermediate hosts], which can become very large and can cause death when untreated or disrupted.


1

I haven't really found much on this topic (besides popular sites) but I can summarize it here: There are quite some tapeworms (or cestoda), I found numbers of up to 3500 species. They attach to the intestinal wall of the humans and then start to take up predigested food through their skin. With that, they reduce food from their host and start to grow, some ...


1

Thus, there is a significant selection pressure for humans to develop resistance but no (or almost no) pressure for toxoplasmosis to counter human resistance. Well, I think in this case "Significant" isn't qualified. Significant selective pressure can come in many forms, but as you mention about 30% of humans are infected with Toxopolasma, and the vast ...


1

In the study by Whitfield 1990 (1) I found the information that the parasitic wasp from family Ichneumonidae have interesting symbiotic viruses called polydnaviruses. This virus stay as provirus in the wasps genome and is transmitted vertically between subsequent generations of parasitoid. It does not harm the wasp and it is transmitted to the wasps hosts ...



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