Thursday, March 19, 2020

Homonyms quiz - Emphasis

Homonyms quiz Homonyms quiz Homonyms are words that are pronounced or spelt in the same way but have different meanings – there and their, for example. This ten-question quiz will test you on some of the most commonly confused homonyms. How well do you know your allusions from your illusions and your pails from your pales? After youve answered the questions and been given your score, an explanation of each pair of homonyms will appear. Good luck! He gives the ____ of knowing exactly what needs doing, but I wonder if he really does. allusionillusionCould you ____ with me for ten minutes? I’m just running a little late. bearbareIs everyone here? Do we have a full ____? complementcomplimentI’d appreciate it if you could be ____ about this; we’re keeping it quiet until the details are finalised. discreetdiscreteOur guest speaker this week is the ____ Dr Greggs. eminentimminentThe project is now in ____ fourth week, so I thought it would be a good idea to have a catch up. it'sitsWe felt his comments were beyond the ____ and hope he plans to issue an apology. palepailOur ____ concern is that the project may not be completed before the June deadline. principleprincipalWe’ll give you free ____ regarding design and pictures. reignreinCan we arrange to have some branded ____ made? stationarystationery How did you do? Let us know by popping a comment in the box below.

Monday, March 2, 2020

Commensalism Definition, Examples, and Relationships

Commensalism Definition, Examples, and Relationships Commensalism is a type of relationship between two living organisms in which one organism benefits from the other without harming it. A commensal species benefits from another species by obtaining locomotion, shelter, food, or support from the host species, which (for the most part) neither benefits nor is harmed. Commensalism ranges from brief interactions between species to life-long symbiosis. Commensalism Definition The term was coined in 1876 by Belgian paleontologist and zoologist Pierre-Joseph van Beneden, along with the term mutualism. Beneden initially applied the word to describe the activity of carcass-eating animals that followed predators to eat their waste food. The word commensalism comes from the Latin word commensalis, which means sharing a table. Commensalism is most often discussed in the fields of ecology and biology, although the term extends to other sciences. Terms Related to Commensalism Commensalism is often confused with related words: Mutualism - Mutualism is a  relationship in which two organisms benefit from each other. Amensalism - A relationship in which one organism is harmed while the other is not affected. Parasitism - A relationship in which one organism benefits and the other is harmed. Theres often debate about whether a particular relationship is an example of commensalism or another type of interaction. For example, some scientists consider the relationship between people and gut bacteria to be an example of commensalism, while others believe it is mutualistic because humans may gain a benefit from the relationship. Examples of Commensalism Remora fish have a disk on their heads that makes them able to attach to larger animals, such as sharks, mantas, and whales. When the larger animal feeds, the remora detaches itself to eat the extra food.Nurse plants are larger plants that offer protection to seedlings from the weather and herbivores, giving them an opportunity to grow.Tree frogs use plants as protection.Golden jackals, once they have been expelled from a pack, will trail a tiger to feed on the remains of its kills.Goby fish live on other sea animals, changing color to blend in with the host, thus gaining protection from predators.Cattle egrets eat the insects stirred up by cattle when they are grazing. The cattle are unaffected, while the birds gain food.The burdock plant produces spiny seeds that cling to the fur of animals or clothing of humans. The plants rely on this method of seed dispersal for reproduction, while the animals are unaffected. Types of Commensalism (With Examples) Inquilinism - In inquilinism, one organism uses another for permanent housing. An example is a bird that lives in a tree hole. Sometimes epiphytic plants growing on trees are considered iniquilism, while others might consider this to be a parasitic relationship because the epiphyte might weaken the tree or take nutrients that would otherwise go to the host. Metabiosis - Metabiosis is a commensalistic relationship in which one organism forms a habitat for another. An example is a hermit crab, which uses a shell from a dead gastropod for protection. Another example would be maggots living on a dead organism. Phoresy - In phoresy, one animal attaches to another for transport. This type of commensalism is most often seen in arthropods, such as mites living on insects. Other examples include anemone attachment to hermit crab shells, pseudoscorpions living on mammals, and millipedes traveling on birds. Phoresy may be either obligate or facultative. Microbiota - Microbiota are commensal organisms that form communities within a host organism. An example is the bacterial flora found on human skin. Scientists disagree on whether microbiota is truly a type of commensalism. In the case of skin flora, for example, there is evidence the bacteria confer some protection on the host (which would be mutualism). Domesticated Animals and Commensalism Domestic dogs, cats, and other animals appear to have started out with commensal relationships with humans. In the case of the dog, DNA evidence indicates dogs associated themselves with people before humans switched from hunting-gathering to agriculture. Its believed the ancestors of dogs followed hunters to eat remains of carcasses. Over time, the relationship became mutualistic, where humans also benefited from the relationship, gaining defense from other predators and assistance tracking and killing prey. As the relationship changed, so did the characteristics of dogs. Reference:  Larson G (2012). Rethinking dog domestication by integrating genetics, archeology, and biogeography. Proceedings of the National Academy of Sciences of the United States of America. 109: 8878–83.