Answer:
B. In the real world, random and unpredictable events occur, so the Lotka-Volterra parameters vary over time
Explanation:
Lotka-Volterra equations are mathematical models that explain biological prey-predator interactions among two species, considering the following assumptions,
-
The ecosystem is isolated and closed. There is no migration.
- The whole individuals are reproductively equivalent.
- In the absence of the predator, prey shows an exponential growth rate. The prey is in the ideal environment.
- In the absence of the prey, the predator population decreases exponentially. The predator environment is also ideal, but it is limited by the prey density.
- The predation rate is proportional to the encounters rate, which also depends on density.
- The predators affect the prey populations, making it decrease proportionally to the number of prey and predators present.
- The prey population also influence the predator population, proportionally to the number of encounters between the two species.
In these equations, the variable D is the number of predators, and P the number of preys.
The parameters are always constant:
- a1: predator hunting success.
- r2: predator growth rate.
- a2: the success of the predator in hunting and feeding.
In nature, there are many factors affecting interactions. Dense-dependent factors and dense-independent factors. Also in reality there are stochastic factors. <em>Stochasticity refers to the variability in the system involving those factors that are affecting or influencing the population growth. Stochasticity might be related to good years and bad years for population growth.</em>
In a real situation, the compliance of the whole assumptions does not occur. The previously mentioned constants might vary, changing continuously the interaction among the predator and the prey. These parameters change in different degrees, resulting in different circumstances for both species.
Answer: Autocrine signal, paracrine signal and endocrine signal.
Explanation:
Testosterone is an example of hormone which shows its effect on different locations of the cells.
The autocrine signal can be defined as the siganals which shows its effect on the cell from where it is being produced. This means a cell targets itself.
Then comes the paracrine signals in which signals acts locally on the cells nearby it. The cells close together to the cells producing chemical signals is being affected.
The endocrine signals can be defined as the effect of the hormone on the distant cells. The signals is produced by the cells somewhere else but is carried through the bloodstream to the distant cells.
All of the three effects is being shown by testosterone autocrine, endocrine and paracrine.
The right answer is chromosome > DNA > gene.
Living cell element, of characteristic shape and in constant number, located in the nucleus of the cell.
DNA, which is our chromosome, carries the genes
. The DNA molecule, also known as deoxyribonucleic acid, is found in all our cells.
The gene is a piece of this DNA that corresponds to a particular genetic information that codes for a single protein. So it's a very small portion of chromosome.
It is most likely the <span>ventral ramus into the dorsal root ganglion. A spine nerve arises from the spine cord as branch-like structures which converge to form the ventral or dorsal root. This is the pathway for the motor and sensory neuron.</span>
