<h2>DNA </h2>
Explanation:
1) Experiment done by Griffith:
- Griffith used two related strains of bacteria, known as R and S
- R bacteria were nonvirulent, meaning that they did not cause sickness when injected into a mouse whereas mice injected with live S bacteria developed pneumonia and died
- Griffith tried injecting mice with heat-killed S bacteria (that is, S bacteria that had been heated to high temperatures, causing the cells to die), the heat-killed S bacteria did not cause disease in mice
- When harmless R bacteria were combined with harmless heat-killed S bacteria and injected into a mouse, not only did the mouse developed disease and died, but when Griffith took a blood sample from the dead mouse, he found that it contained living S bacteria
- Griffith concluded that the R-strain bacteria must have taken up what he called a transforming principle from the heat-killed S bacteria, which allowed them to transform into smooth-coated bacteria and become virulent
2) Experiment done by Avery:
- Avery, McCarty and MacLeod set out to identify Griffith's transforming principle
- They began with large cultures of heat-killed S cells and, through a long series of biochemical steps progressively purified the transforming principle by washing away, separating out, or enzymatically destroying the other cellular components
- These results all pointed to DNA as the likely transforming principle but Avery was cautious in interpreting his results
- He realized that it was still possible that some contaminating substance present in small amounts, not DNA, was the actual transforming principle
3) Experiment done by Hershey and Chase:
- Hershey and Chase studied bacteriophage, or viruses that attack bacteria
- The phages they used were simple particles composed of protein and DNA, with the outer structures made of protein and the inner core consisting of DNA
- Hershey and Chase concluded that DNA, not protein, was injected into host cells and made up the genetic material of the phage
1) To calculate the population density you first need to know how many <span>squirrels form that population.
To calculate the number of</span><span> squirrels:
1500</span> squirrels is the capacity, so it's equivalent to 100%
So how much squirrels are present in 80% of the area:
1500----100 %
x----------80 %
x= 1200 <span>squirrels
</span>
2)Population Density equals the number of squirrels divided by the land area
In the first part was calculated the number of squirrels and the exercise gives us the area in hectares so the only thing left to do is divide them.
(since this exercise doesn't specify that the area needs to be in a certain measurement we can use hectares)
Population Density = 1200/ 150
<span>The population density of the squirrels is 8 per hectare</span>
Answer:
Function and structure are related, because of a certain structure a living thing make contain makes the object function the way it does. There are a lot of structural future in humans, plants, animal and all living things.
Explanation:
Its natural selection. Due to genetic variations, some animals have traits more desirable then others. This animals will survive and reproduce better, over time creating a whole new species.