Life cycles occur in a variety of forms, all involving the exploitation of one or more hosts. Those that must infect more than one host species to complete their life cycles are said to have complex or indirect life cycles, while those that infect a single species have direct life cycles.
If a parasite has to infect a given host in order to complete its life cycle, then it is said to be an obligate parasite of that host; sometimes, infection is facultative — the parasite can survive and complete its life cycle without infecting that particular host species. Parasites sometimes infect hosts in which they cannot complete their life cycles; these are accidental hosts.
A host in which parasites reproduce sexually is known as the definitive, final or primary host. In intermediate hosts, parasites either do not reproduce or do so asexually, but the parasite always develops to a new stage in this type of host
A) Water freezing
This is called the process of turning water as a liquid to its solid form which is ice.
Ice is almost together as one unlike liquid. This is why the molecules are more orderly.
The process of freezing is exothermic which means the heat has to be removed in the process.
Answer:
the electric field direction should be in positive y axis
Explanation:
Lets assume that charge on particle is positive and it isequal to +q
First calculate the magnetic force on it
for direction
use Right Hand Rule which will give the direction and by using his the direction will come towards negative y axis.
As given in the question that charge particle does not change their velocity so we need to apply electric field in such a way that electric force direction should be opposite to the magnectic field.
and magnitude should be same as magnectic force and also direcion of electric force depend on the direction of elecric field when charge is positive because electric force 
Hence the electric field direction should be in positive y axis
Conservation of momentum: total momentum before = total momentum after
Momentum = mass x velocity
So before the collision:
4kg x 8m/s = 32
1kg x 0m/s = 0
32+0=32
Therefore after the collision
4kg x 4.8m/s = 19.2
1kg x βm/s = β
19.2 + β = 32
Therefore β = 12.8 m/s
It is false. Because the amount of energy carried in the wave is inversely related to the length of the waves wavelength. To correct the statement it should be that the shorter the radiation's wavelength the stronger is the radiation's energy.
