Answer:
1.The pleural cavity aids optimal functioning of the lugs during breathing. It transmits movements of the chest wall to the lungs, particularly during heavy breathing. The closely approved chest wall transmits pressures to the visceral pleural surface and hence to the lung (10-19.
2.The diaphragm, located below the lungs, is the major muscle of respiration. It is a large, dome-shaped muscle that contracts rhythmically and continually, and most of the time, involuntarily. Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarge.
Explanation:
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.
The DNA polymerases are enzymes that create DNA molecules by assembling nucleotides, the building blocks of DNA. These enzymes are essential to DNA replication and usually work in pairs to create two identical DNA strands from one original DNA molecule. During this process, DNA polymerase “reads” the existing DNA strands to create two new strands that match the existing ones.
Every time a cell divides, DNA polymerase is required to help duplicate the cell’s DNA, so that a copy of the original DNA molecule can be passed to each of the daughter cells. In this way, genetic information is transmitted from generation to generation.
Before replication can take place, an enzyme called helicase unwinds the DNA molecule from its tightly woven form. This opens up or “unzips” the double stranded DNA to give two single strands of DNA that can be used as templates for replication.
DNA polymerase adds new free nucleotides to the 3’ end of the newly-forming strand, elongating it in a 5’ to 3’ direction. However, DNA polymerase cannot begin the formation of this new chain on its own and can only add nucleotides to a pre-existing 3'-OH group. A primer is therefore needed, at which nucleotides can be added. Primers are usually composed of RNA and DNA bases and the first two bases are always RNA. These primers are made by another enzyme called primase.
Although the function of DNA polymerase is highly accurate, a mistake is made for about one in every billion base pairs copied. The DNA is therefore “proofread” by DNA polymerase after it has been copied so that misplaced base pairs can be corrected. This preserves the integrity of the original DNA strand that is passed onto the daughter cells.

A surface representation of human DNA polymerase β (Pol β), a central enzyme in the base excision repair (BER) pathway. Image Credit: niehs.nih.gov
Structure of DNA polymerase
The structure of DNA polymerase is highly conserved, meaning their catalytic subunits vary very little from one species to another, irrespective of how their domains are structured. This highly conserved structure usually indicates that the cellular functions they perform are crucial and irreplaceable and therefore require rigid maintenance to ensure their evolutionary advantage.
Answer:
Plants absorb carbon dioxide, water and sunlight to make their own food, grow and release oxygen through photosynthesis. They're a huge part in keeping our air clean.
Explanation:
Hope this helps.
So Mendel got roughly 75% yellow and 25% green in f2. This means that f1 contains all heterozygous genes, as shown below
Y y
Y YY Yy
y Yy yy
Summary: 75% YY or Yy, 25% yy
Which means that green (y) is a recessive phenotype, while yellow (Y) is a dominant phenotype, since plants with heterozygous genotype Yy express the yellow trait.