Answer:
<u><em>The correct option is C) genetic variation</em></u>
Explanation:
Genetic variation can be described as the differences present in the genetic material i.e DNA of organisms present in a population. Genetic diversity allows organisms of a species to better adapt to an environment. A population in which the genetic variability is scarce might become wiped out by a disease or an invading predator.
As the birds show different variations hence the term that best described them is genetic variation.
The given question says that a student has constructed a model of cellular transport using fences and several gates.
This model can be used to demonstrate the cellular transport.
The gates of the fences can be supposed as the protein pumps and the other fence demonstrates the lipid bilayer.
Let’s suppose in the fence, there are many cattles, and outside, there are less cattles, but the student open the gate and bring more cattles inside the fence. In this case, the transport of the cattles is similar to the active transport of the molecules using protein pumps. At cellular level, the energy for the active transport is provided by ATP molecules.
Now, let’s say, the student wants to feed the cattles with some nutrition rich food, which can help in maintaining the health of the cattles. The student fills his car with the cattle food and he enters inside the fence through gates. In this case, the food was not present in the fence, but was abundant in the outside environment, so, the diffusion would occur. But food cannot come self, without help of others, so, the movement is facilitated by the car, as it is done by the carrier proteins. Hence, it is an example of facilitated diffusion.
The amount of space an object has
Explanation:
The answer is A.
When the body temperature returns to normal,the respiratory system sends a message to the skeletal system to stop shivering.
Answer:
lytic, because of the quick onset of symptoms after infection
Explanation:
As seen in the question above, the SARS virus tends to develop symptoms very quickly when it is infecting a person. This speed in the development of symptoms is a characteristic of the lytic cycle, in relation to the reproductive cycle of viruses. This is because in the lytic cycle, a virus can infect many cells at once, which accelerates the development of the disease. This cycle allows the virus to use all of the cell's biological machinery to reproduce more copies of the virus. When these copies are ready, the virus causes the destruction of the host cell and the release of new viruses to other cells, where the whole process will be repeated. This is all done very quickly.
The lysogenic cycle does not cause the rapid infection of thousands of cells, since it is necessary that there is an adaptation between the DNA of the cell and the DNA of the virus. This slows down the infection process and, therefore, symptoms appear more slowly.
