Answer:
I don't know exactly what you need but I give you an example so that you can create your samples through the Excel program, I hope it helps.
Just enter your sampling frame (the clients of which you have contact information) in the spreadsheet. Once you have a sampling frame (possible respondents) in Excel, you can easily select a random sample among them. For example, in your case that it is a work of biology and neceists three random samples here you can apply it with the following rules:
-Add a new column in the spreadsheet and name it "Random Number".
-In the first cell below your header row, type "= RAND ()".
-Press “Enter” and a random number will appear in the cell.
-Copy and paste the first cell in the other cells of the column.
-Once each row has a random number, organize the records from the "Random number" column.
-Then, select the first samples. In this way you will randomly choose from all samples.
b. a river contaminated with the Giardia protozoan
c. a doorknob contaminated with the cold virus
d. an asymptomatic person infected with HIV
e. a mosquito infected with the malaria protozoan
Answer:
The correct option is: c. a doorknob contaminated with the cold virus
Explanation:
Fomites are the inanimate objects or substances that can get contaminated with the pathogens and are capable of transferring the pathogens to the new hosts.
Sterilization of the possible fomites should be done in order to prevent cross-infection.
Examples of fomites are hair, towels, clothes, door knobs, cups, switches, handrails, remote controls, pens, syringes, bedding, etc.
Bacterial Population
Time
Which of these most likely explains why the bacterial population stopped growing?
The bacteria mutated from photosynthetic to carnivorous organisms and consumed one another until all the individuals were dead.
The bacteria reproduced in the system but eventually died due to limited resources
The bacteria became diseased and were unable to survive in the closed system
The bacteria competed for nutrients and died after all the nutrients were consumed
The statement that most likely explains the stop of bacterial populations to grow is the bacteria competed for nutrients and died after all the nutrients were consumed.
Bacterial growth may be defined as the proliferation of bacterium into two daughter cells, in a process called binary fission.
When there are enough nutrients in the petri dish, a rapid increase is shown in the graph, but during the course of time when nutrients become limited, it affects the growth of the bacterial population.
Therefore, the statement that most likely explains the stop of bacterial populations to grow is the bacteria competed for nutrients and died after all the nutrients were consumed.
To learn more about Bacterial growth, refer to the link:
B - The bacteria competed for nutrients and died after all the nutrients were consumed
Answer:
Nitrogenous bases
Explanation:
DNA is a nucleic acid molecule that acts as the genetic material of the organisms. The structure of DNA is made of two strands of nucleotides that are linked together and form a helical structure. The helical structure is known as the double-helical model with a ladder-like appearance.
The backbone of the ladder is composed of the sugar and phosphate groups at alternate positions whereas the staircase of the ladder are made of the different type of nitrogenous bases (A, G, T, C) joined by the hydrogen bond.
Thus, Nitrogenous bases is the correct answer.
Independent: ____________
Dependent:___________
3. What is a negative control you should use to rule out alternative explanations for a positive result?
4. In Parts 2 and 4, you measured the diameter of the micronucleus using fluorescence microscopy and electron microscopy. How do the measurements compare? Which of the two types of microscopy above do you believe was most accurate? Why?
Phagocytosis queries are given detailed in the following way
Explanation:
1.Phagocytosis is a process wherein a cell binds to the item it wants to engulf on the cell surface and draws the item inward while engulfing around it.Phagocytosis differs from other methods of endocytosis because it is very specific and depends on the cell being able to bind to the item it wants to engulf by way of cell surface receptors. Phagocytosis won’t happen unless the cell is in physical contact with the particle it wants to engulf.
2.A hypothesis states a presumed relationship between two variables in a way that can be tested with empirical data. ... The cause is called the independent variable; and the effect is called the dependent variable.
Independent and Dependent Variable Examples. In a study to determine whether how long a student sleeps affects test scores, the independent variable is the length of time spent sleeping while the dependent variable is the test score. You want to compare brands of paper towels, to see which holds the most liquid.
3.A negative control is a control group in an experiment that uses a treatment that isn't expected to produce results. A positive control is a control group in an experiment that uses a treatment that is known to produce results.
A negative control is part of a well-designed scientific experiment. The negative control group is a group in which no response is expected. It is the opposite of the positive control, in which a known response is expected.
These two controls, when both are successful, are usually sufficient to eliminate most potential confounding variables: it means that the experiment produces a negative result when a negative result is expected, and a positive result when a positive result is expected.
4.Electron microscopes differ from light microscopes in that they produce an image of a specimen by using a beam of electrons rather than a beam of light. Electrons have much a shorter wavelength than visible light, and this allows electron microscopes to produce higher-resolution images than standard light microscopes.Microscopes are used to produce magnified images. ... light microscopes are used to study living cells and for regular use when relatively low magnification and resolution is enough. electron microscopes provide higher magnifications and higher resolution images but cannot be used to view living cells.
Fluorescence microscopy is used
a fish tapeworm
an eagle eating a mouse
a tiger eating a gazellean antelope
a redwood tree
The example of an organism at the second trophic level is an eagle eating a mouse.
An example of an organism at the second trophic level is an eagle eating a mouse. At the second trophic level, organisms are considered primary consumers, as they consume producers such as plants or algae.
The second trophic level is comprised of herbivores. From the provided list, the only example of an organism at this level is a cow eating grass, as it directly consumes a primary producer.
In biology, a trophic level refers to the position an organism occupies in a food chain. The second trophic level consists of herbivores which are organisms that directly consume producers - often plants. The example of an organism at the second trophic level from your list is a cow eating grass. The cow, being an herbivore, falls under this category as it consumes grass, a primary producer. All other organisms listed are either producers (redwood tree), parasites (fish tapeworm) or carnivores (eagle, tiger), and therefore, do not belong to the second trophic level.
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