Antibodies are produced when the body is exposed to a pathogen. Antibody production is a function of the specific immunity arm of the immune system.
During the first encounter with a pathogen, antibody production against that pathogen is a bit slow and not very vigorous. However, memory of that pathogen is kept in memory cell which are a type of lymphocyte.
On a second encounter with the same type of pathogen, the immune system specifically remembers the pathogen and the response this time round is faster, very vigorous, specific and very effective.
Vaccines follow this principle, making good use of immune memory.
Answer:
c. because arteries carry high pressure blood from the heart
Explanation:
Arteries carry the oxygenated blood that is pumped directly from the left ventricle of the heart. Since they receive blood from the heart, the blood pressure is higher in arteries than veins. To withstand the higher pressure of blood pumped by heart, arteries have thicker walls than the walls of veins.
Answer:
I'm assuming you are referring to a population such as a forest population. Appropriate answers would be 1) for a diverse food chain. 2) so the mechanics of an ecosystem can work and have multiple sources. IF you are referring to a population such as a given population of a species, it is important to have variety so mutations can occur and genetics can mix. This kicks off the survival of the fittest and Darwin's theory's. This, of course, takes plenty of time to see any change but genetic mutation is essentially survival of the fittest. If a mutation increases survival likelihood, they are now more fit to survive, thus creating a new "weak variation" in comparison to a new "strong variation" within a species. Read below for furhter explanation on previous stated points. I really hope this helps!
Explanation:
1) Populations of consumers would struggle if there is only one producer. If there are multiple variations of any producers, it will allow the consumers to thrive since there is an abundance and variation of producers. The same can apply to consumers since there are herbivore consumers and carnivore consumers. A population of wolves would struggle if their only food source were squirrels. If rabbits and deer were in the mix, wolves would thrive a lot easier.
2) If there was only one species of decomposer within an area, the decomposition process would take much more time due to a lack of efficiency with time. If there are multiple decomposers it wouldn't be much of an issue. Same goes with scavengers. There would be a lot of waste if only on scavenger lived within an area compared to multiple.
Hey there!
Sorry for the late reply, but the answer is in fact
The burning of fossil fuels is having a negative effect on the planet via global warming. In fact, in 2006, Western Europe experienced some of the hottest weather in history.