Answer:
The most obvious result of the removal of the top predators in an ecosystem is a population explosion in the prey species. ... When prey becomes more scarce, the predator population declines until prey is again more abundant. Therefore, the two balance each other. When the predators are removed, prey populations explode.
Answer: Methylene blue can be used to stain DNA of a cell because it (forms ionic bonds with DNA).
Explanation:
To examine the components of a cell usually under a microscope, a stain or dye is being used to provide a clear and defined view of the area under study.
The deoxyribonucleic acid (DNA) of a cell which contains the hereditary information of the cell is located in the nucleus.
Methylene blue is a type of stain used by biologists which helps them view microscopic life in brilliant color. It is a cationic stain (positively charged blue dye); and binds to negatively charged parts of the cells, such as nucleus (DNA) and RNA in the cytoplasm (with lower affinity).
When DNA of a cell comes in contact with methylene blue on a slide, their opposite charges attract, causing methylene blue's "rings" to slide in between the "rungs" of the DNA "ladder." As a result, a rich blue stain that identifies the location of the cell nucleus can be observed. This produces a photosensitive reaction which can then be viewed under the microscope.
Therefore is can be used to stain the DNA of cell because it forms ionic bonds with DNA.
Answer: D) directional selection
Explanation:
The characteristics of the poppies shifted in response to the changed environment.
Answer:
film sensitive to radiation that is removed and developed to measure exposure.
a device used for monitoring individual cumulative exposure to ionizing radiation.
Explanation:
Film badges are monitoring devices that contain photographic film which measures and record the wearer’s exposure to different ionizing radiation such as X-rays, gamma rays and beta particles. The photographic film within film badges is very sensitive, functions as a detector, and is enclosed in a vapor and light resistance cover which disallows chemical vapors, light or moisture to have an effect on the film. Film badges give a lasting radiation record and it can also differentiate between different energies of photons.
Answer:
In hypertonic solutions, the cells will shrink and in hypotonic solutions the cells will fill up
Cells with cell walls will be able to control their tonicity better than cells without cell walls.
Explanation:
Cells with cell walls
- In a hypertonic solution (high solute concentration), water will flow out of the cell into the solution until equilibrium is reached. If the solution has a high concentration of solute the cell may undergo<u> plasmolysis where the plasma membrane detaches from the cell wall.</u>
- In a hypotonic solution: Water will flow into the cell because it has a higher solute concentration compared to the solution. This will continue until the cell is <u>turgid</u>. If more water continues to enter the cell, the cell is at risk of bursting, this takes a while because the cell wall will withstand the pressure.
Cells without cell walls
- In a hypertonic solution: Water will diffuse out of the cell, however there is no cell wall so cell is in danger of shrinking and dying.
- In hypotonic solution: Water will diffuse into cell,the cell will become turgid and if water keeps moving in the cell will burst because it has no cell wall to resist the pressure.
