Which organ system is responsible for transporting oxygen throughout the human body?

You want to study the effect of agriculture run-off on the rate of antibiotic resistant bacteria in ponds. You gather samples fr

Yuliya22 [10]

Complete question:

You want to study the effect of agriculture run-off on the rate of antibiotic-resistant bacteria in ponds. You gather samples from ponds surrounded by high-density livestock areas and from ponds at least ten miles from agriculture activities. You grow the bacteria on plates and test how resistant they are to antibiotics. Based on this experiment, the proximity of the pond to agriculture would be best categorized as what?

the control group
the independent variable
the dependent variable
the hypothesis

Answer:

2. the independent variable

Explanation:

During an experiment, data from an experimental group is compared with the data from a control group. Both groups are selected from the same pool or population, so they are identical in all aspects except for the independent variables.

The election of a control group is essential in an experiment. Its principal purpose is to allow the discrimination of the results obtained by the treatment in the study, from the results that might be a consequence of other factors. The control group does not receive any treatments. It is used to identify any other factors influencing the results obtained in the study, apart from the modified variables of the treatment.

The <u>experimental group</u> is the one that receives the experimental procedure or treatment. The researcher voluntarily changes the independent variables in the experimental group to observe how they affect the group under study. These variables are kept constant in the control group, not influencing the results, while the experimental group receives the treatment. There can be several experimental groups.

Independent (manipulated) variable: Refers to all the variables in an experiment that provoke a response in another variable. An independent variable is the one that<u> changes</u> or is <u>controlled</u> and <u>modified</u> in the experiment to <u>analyze how another variable responds to it</u>. It changes to analyze its effects on the dependent variable. Usually, the independent variable is represented by the X letter.

Dependent variable: Refers to the variable that depends and reacts to any change in the independent variable. It represents a quantity of something which value depends on how the independent variable is modified. This change might be proportional or inversely proportional to the change in the manipulated variable. It is usually identified by the letter Y.

The hypothesis is a conjecture. The researcher hypothesizes in order to predict what is going on or what is expected to occur. A hypothesis is a claim of how it works a relation between two or more variables. Usually, it is written in the present time.

----------------------------------------------------------------------------------------------------------

The proximity of the pond to agriculture might be considered as an <em>independent variable</em>.

The researcher chooses ponds according to their distance from the crops. In the exposed example, the researcher chose a pond is surrounded by high-density livestock areas and another one at least ten miles away.

The magnitude of run-off might depend on how far the pond is from the crops.

4 0

2 years ago

Nuclear energy is a useful source of power but has disadvantages. What is a

mylen [45]

<h2>Nuclear energy:</h2>

The energy which is harvested due to the nuclear fusion or fission occurring in a reactor is called nuclear energy. Though this energy has much application it has certain disadvantages.

<h2>Disadvantages of nuclear energy:</h2>

The radioactive waste originating from atomic power plants and the reactors used act an extraordinary danger to Mother Nature and people.
Improper disposal of radioactive waste released from the reactors, act as base of many deathly diseases.
Another major disadvantage of utilizing nuclear energy is that it needs a ton of venture to set up an atomic power station. Developing an atomic power plant requires enormous capital cost.
When the waste of this energy production process is lead to river body it causes eutrophication which causes the death of the aquatic life.

7 0

2 years ago

Read 2 more answers

Which statements explain reasons why unconformities occur? Check all that apply.

allsm [11]

Rocks erode and sediment is deposited.

No sediment is deposited over a long time

Explanation:

Unconformity can form when rocks erode and sediment is deposited in that process, it can also be a period of non-deposition for a very long time. Unconformity represents a time break in the stratigraphic record.

There are different types of unconformity.
Unconformity is due to a period of non-deposition or series of erosion which is followed by deposition of sediments.
Usually, they are expressed by the presence of unconformable beds or some prolonged erosional surfaces that are preserved.

Learn more:

Sedimentary rocks brainly.com/question/2740663

#learnwithBrainly

6 0

3 years ago

Read 2 more answers

The base on the mRNA strands are called?

nataly862011 [7]

Answer:

The base on the mRNA strands are called codons.

4 0

3 years ago

Read 2 more answers

How does a presynaptic neuron know just how much of a certain neurotransmitter (NT) it has released into the synapse?

Llana [10]

Answer:

A presynaptic neuron knows when and how much of a certain neurotransmitter it has to release into the synapse by the frequency of the action potential.

Explanation:

Two nuerons connect to each other through synapse. When an action potential, or nerve impulse, arrives at the axon terminal, it activates voltage-gated calcium channels in the cell membrane, then the calcium which is present in hi highconcentration outside the neuron than inside, rushes into the cell. The Calcium then allows synaptic vesicles to fuse with the axon terminal membrane, releasing neurotransmitter into the synaptic cleft.

The nuerotransmitter than binds to the receptors at the post-synaptic cleft and causes the opening or closing of the channels, hence, depolarizing or hyperpolarizing the cells.This can produce a change in the membrane potential—voltage across the membrane of the receiving cell.

4 0

2 years ago