Answer:
The eukaryotic cell nucleus. Visible in this diagram are the ribosome-studded double membranes of the nuclear envelope, the DNA (complexed as chromatin), and the nucleolus. Within the cell nucleus is a viscous liquid called nucleoplasm, similar to the cytoplasm found outside the nucleus.
Answer:
Auxin is a key regulator of plant growth and development, orchestrating cell division, elongation and differentiation, embryonic development, root and stem tropisms, apical dominance, and transition to flowering
Explanation:
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Answer:
The simultaneous effect of a predator population on a prey population and a prey population on a predator population over time.
Explanation:
The mathematical models of Lotka-Volterra equations explain the existing interaction between species in which prey and predator influence and affect each other. The model follows a few 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.
- When there is no prey, the predator population decreases exponentially because of the lack of food. The predator environment is ideal, but it is limited by prey density.
- The predation rate is proportional to the encounters rate, which also depends on density.
- The predators affect the prey populations, inducing its decrease proportionally to the number of prey and predators present.
- The prey population also influences 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 prey items.
The parameters are always constant:
• r1: prey growth rate.
• a1: predator hunting success.
• r2: predator growth rate.
• a2: the success of the predator in hunting and feeding.
In nature, many factors affect interactions, such as dense-dependent factors and dense-independent factors. Also, in reality, there are stochastic factors. Stochasticity refers to the variability in the system involving those factors that are affecting or influencing population growth. Stochasticity might be related to good years and bad years for population growth.
In real situations, the compliance of the whole assumption does not occur. The previously mentioned constants might vary, constantly changing the interaction between the predator and the prey. These parameters change in different degrees, resulting in varying circumstances for both species.
Nowadays, different countries are constantly emerging and
expanding their liabilities which may include the field of medicine. The
disease that is being discussed by the instructor that is considered nearly
eradicated is probably the measles. This disease is caused by Paramyxovirus which
is a major respiratory pathogen among infants and young children. Measles is
also known as “rubeola virus”, an acute, highly respiratory symptoms and a
maculopapular rash that affects the mouth, head, body and extremities. It
begins with the appearance of Koplik spots which may end up to some
complications like symptomatic encephalitis and subacute sclerosing
panencephalitis(SSPE). In order to prevent this type of disease MMR(Measles, Mumps
& Rubella) Vaccine is needed. According to some of the reports, it is still
common to some of the countries, but WHO campaigns to eradicate the disease worldwide
by the year 2020.