Answer:
The goal of disinfection of public water supplies is the elimination of the pathogens that are responsible for waterborne diseases. The transmission of diseases such as typhoid and paratyphoid fevers, cholera, salmonellosis, and shigellosis can be controlled with treatments that substantially reduce the total number of viable microorganisms in the water.
While the concentration of organisms in drinking water after effective disinfection may be exceedingly small, sterilization (i.e., killing all the microbes present) is not attempted. Sterilization is not only impractical, it cannot be maintained in the distribution system. Assessment of the reduction in microbes that is sufficient to protect against the transmission of pathogens in water is discussed below.
Chlorination is the most widely used method for disinfecting water supplies in the United States. The near universal adoption of this method can be attributed to its convenience and to its highly satisfactory performance as a disinfectant, which has been established by decades of use. It has been so successful that freedom from epidemics of waterborne diseases is now virtually taken for granted. As stated in Drinking Water and Health (National Academy of Sciences, 1977), "chlorination is the standard of disinfection against which others are compared."
However, the discovery that chlorination can result in the formation of trihalomethanes (THM's) and other halogenated hydrocarbons has prompted the reexamination of available disinfection methodology to determine alternative agents or procedures (Morris, 1975).
The method of choice for disinfecting water for human consumption depends on a variety of factors (Symons et al., 1977). These include:
its efficacy against waterborne pathogens (bacteria, viruses, protozoa, and helminths);
the accuracy with which the process can be monitored and controlled;
its ability to produce a residual that provides an added measure of protection against possible posttreatment contamination resulting from faults in the distribution system;
the aesthetic quality of the treated water; and
the availability of the technology for the adoption of the method on the scale that is required for public water supplies.
Economic factors will also play a part in the final decision; however, this study is confined to a discussion of the five factors listed above as they apply to various disinfectants.
The propensity of various disinfection methods to produce by-products having effects on health (other than those relating to the control of infectious diseases) and the possibility of eliminating or avoiding these undesirable by-products are also important factors to be weighed when making the final decisions about overall suitability of methods to disinfect drinking water. The subcommittee has not attempted to deal with these problems since the chemistry of disinfectants in water and the toxicology of expected by-products have been studied by other subcommittees of the Safe Drinking Water Committee, whose reports appear in Chapter III of this volume (Chemistry) and Chapter IV (Toxicity) of Drinking Water and Health, Vol. 3.
Organization of the Study
The general considerations noted in the immediately following material should be borne in mind when considering each method of disinfection. Available information on the obvious major candidates for drinking water disinfection—chlorine, ozone, chlorine dioxide, iodine, and bromine—is then evaluated for each method individually in the following sections. Other less obvious possibilities are also examined to see if they have been overlooked unjustly in previous studies or if it might be profitable to conduct further experimentation on them. Disinfection by chloramines is dealt with in parallel with that effected by chlorine because of the close relationship the former has to chlorine disinfection under conditions that might normally be encountered in drinking water treatment.
A testcross involves an individual exhibiting the dominant phenotype but an unknown genotype being crossed with an individual that has a(n) ___________ genotype.
Answer and Explanation:
You will find the complete answer and explanation in the attached file due to technical problems.
What does food provide to organisms? homeostasis shelter energy air PLZ HELP ME PLZ PLZ PLZ
Answer:
Option C. is the correct choice.
Explanation:
Food provides "energy" to organisms.
Best Regards!
Answer:
C. Energy
Explanation:
what is a warning safety sign
Answer:
Hey there!
A warning safety sign is a sign that warns you that there may be a safety hazard around you.
Let me know if this helps :)
Which is the FALSE statement about this blood pressure measurement? 147/92 A. 92 is the diastolic number. B. 147 is the systolic number. C. This is a high blood pressure measurement. D. This is a normal blood pressure measurement.
Answer:
The false statement is - option D.
Explanation:
The lower value is known as diastolic number which is the pressure in the arteries when the heart takes rest in between two consecutive heart beats. Diastolic value shows the pressure of arteries when heart fills with blood.
The upper value or number is known as the systolic number, it is the pressure value of arteries of an individual during the contraction of hear. The normal blood person of a health person is range from 80/60mmhg to 120/90 mmhg, above this range is considered as high blood pressure.
Thus, the false statement is - option D.
Can someone please help me!!???
Explanation:
plant cell only
nucleuscell wallchloroplastgolgi apparatus cell membraneribosomeboth plant and animal cells
nucleuscell membraneribosomegolgi apparatusWhat is a pedigree? Please choose the correct answer from the following choices, and then select the submit answer button.
a) a tool to document harmful traits only
b) a type of family tree that can help answer questions about genes and their inheritance patterns
c) a cross between animals other than humans
d) a type of genetic test to determine probability of inheritance
e) a way of following genotypes that are the same as the phenotype
Answer:
b
Explanation:
A pedigree is a genetic representation of a family tree that diagrams the inheritance of a trait or disease though several generations
Answer:
B
Explanation:
Lactose (milk sugar) is a carbohydrate
that is formed by combining galactose and glucose.
Which term best describes this molecule?
ESHTE
O monosaccharide
O disaccharide
O monomer
O starch
Answer:
Lactose is a disaccharide.
Becoz it consists of two components
Answer:
it is B
Explanation:
Which compound is produced during regeneration? PGA G3P RuBP rubisco
Answer:
RuBP is the answers
Answer:
C) RuBP is the answer on edge.
Explanation:
just made a 100%, if you ever have a question i´m glad to help!
i need 4 more brainlest to get expert it would mean a lot if i could have the brainlest, please and thank you!!
Which type of protein will fight disease?
insulin
antibodies
ligaments
genes
Answer: antibodies
Explanation:
using scientific terms, describe the feeding relationships between thr organisms in the following food chain.
grass > grasshopper > field mouse > owl
5000kJ of energy is available in the grass.
Answer:
Grass, meat / flesh
What is chromosomes?Write in brief about the structure of a chromosome.must include all points with explanations
Answer:
Please find the detailed explanation below
Explanation:
A chromosome is thread-like material that carries the long strands of the genetic material (DNA), which in turn carries the gene. The chromosome is the found form of nuclear material in the nucleus.
Due to the long nature of the DNA molecule, they cannot fit into the cell. Hence, to ensure they fit, the cell wraps the DNA molecule around a set of protein called HISTONE proteins to form a NUCLEOSOME. Each nucleosome is made up of DNA coiled around a set of 8 proteins called HISTONE OCTAMER. The nucleosome structure becomes more compacted and further wound around the histone to form a CHROMATIN. This chromatin then undergoes condensation to form the visible CHROMOSOME structure.
Need help with this question
Answer:
she should experiment the hypothesis made by using a different specie in the same vase and record the changes over time
Answer:
A. She should repeat the experiment with the same type of flower and photograph the changes over time.
Please help.. tysm if you do
A. Calcium release
B. Sliding filament mechanism
C. Repeated stimulation
D. Fiber bundling
Answer:
I think its B: Sliding filament mechanism
Explanation:
Answer: D.fiber bundling
Explanation:
what is puberty explain it
The following question has two parts. First, answer Part A. Then, answer Part B.Caused by a mutation, sickle cell anemia is a disorder that affects hemoglobin, the red blood cell molecule that carries oxygen to cells throughout the body. The β chain of the hemoglobin protein is a single chain of amino acids and is 147 amino acids long. In humans, the gene that encodes for the β chain is located on chromosome 11. The diagrams show the DNA, RNA, and amino acid sequence of an unaffected person and a person with sickle cell anemia.image f8707eaefc0147c9bd074a15bb19c344Part A:Where does the mutation that causes this disorder occur?AThe mutation occurs on the DNA.BThe mutation occurs on the RNA.CThe mutation occurs on the ribosomes.DThe mutation occurs on the amino acid.Part B:Which BEST describes the result of this mutation?AThe entire sequence of amino acids is changed.BThe RNA strand does not code for the correct amino acids.CThe change in amino acids shortens the polypeptide sequence.DThe alternation of a single nucleotide encodes for a different amino acid.
the cell wall in plants is made of CHITIN. Correct and rewrite the following
Answer:
See below
Explanation:
The correct statements can be two. Either:
1) The cell wall of plants is made up of cellulose
2) The cell wall of fungi is made up of chitin.
Answer:
chintin is the chemical components of the cell walls of fungi
Which of the following best supports the endosymbiont theory that present-day eukaryotic cells are descendants of a successful symbiotic relationship between a host cell and an engulfed prokaryote?
A. Chloroplasts and mitochondria replicate in a similar manner as some prokaryotes.
B. Chloroplasts are necessary for photosynthesis reactions in plant and bacteria cells.
C. Mitochondria and chloroplasts are able to produce ATP molecules to be used by the cell.
D. Mitochondria use proteins and nutrients produced in other regions of the eukaryotic cell.
Answer:
A. Chloroplasts and mitochondria replicate in a similar manner as some prokaryotes
Explanation:
Endosymbiont theory deals with how eukaryotic organisms were formed from prokaryotic organisms. Prokaryotes such as Bacteria were documented as the first form of life on earth through fossil records before eukaryotes came into light.
Organelles such as Chloroplasts and mitochondria replicate in a similar manner as some prokaryotes. This supports the endosymbiont theory that present-day eukaryotic cells are descendants of a successful symbiotic relationship between a host cell and an engulfed prokaryote
If the number of cigarettes smoked increases, then the risk for lung cancer increases. Independent variable: _______ Dependent variable: _______ If the number of sharks swimming in a coastal region increases, then the number of shark attacks on humans will also increase. Independent variable: _______ Dependent variable: _______ If the amount of milk a person drinks increases, the strength of his or her bones will stay the same. Independent variable: _______ Dependent variable: _______
Complete Question:
Part A: Identifying Variables
Read the following hypotheses and identify the variables.
If the number of cigarettes smoked increases, then the risk for lung cancer increases.
Independent variable: _______
Dependent variable: _______
If the number of sharks swimming in a coastal region increases, then the number of shark attacks on humans will also increase.
Independent variable: _______
Dependent variable: _______
If the amount of milk a person drinks increases, the strength of his or her bones will stay the same.
Independent variable: _______
Dependent variable: _______
Answer/Explanation:
Dependent variables are variables that is dependent on the independent variables. That is, it is the variable that changes as the independent variable changes.
Depedent variable is the main interest if a researcher. It is the variable that is measured in a research work.
In the above given hypotheses, the dependent and independent variables are shown below:
1. "risk for lung cancer" is dependent on the "number of cigarettes smoked".
"Risk for lung cancer" => dependent variable
Number of cigarettes => independent variable
2. "number of shark attacks on humans" is dependent on "number of sharks swimming".
Dependent variable => number of shark attacks on humans
Independent variable => number of sharks swimming
3. Dependent variable => strength of bone
Independent variable => amount of milk a person drinks
Answer:
Lab: Heart Rate
Part A: Identifying Variables
The dependent variable happens as a result of values/changes associated with the independent variable.
Independent variable: number of cigarettes smoked
Dependent variable: risk for lung cancer
Independent variable: number of sharks swimming in a coastal region
Dependent variable: number of shark attacks on humans
Independent variable: amount of milk a person drinks
Dependent variable: the strength of his or her bones
Part B: Heart Rate
Hypothesis: If I hold my breath for 30 seconds, then my heart rate will
(choose 1) increase/decrease.
Independent variable: holding my breath
Dependent variable: heart rate
Part C:
The heart rate decreases because oxygen exchange in the lungs decreases.
This depends on what you chose for heart rate in the hypothesis. If you said the heart rate decreases after holding your breath, and the results showed the heart rate decreased, then the hypothesis is supported. If you said the heart rate decreases after holding your breath, and the results showed the heart rate increased, then you refuted the hypothesis.
Heart rate can change due to an increase or decrease in activity, moving positions such as sitting and standing, and emotions.
Example: Increase in activity—jumping jacks
Hypothesis: If I do five jumping jacks, then my heart rate will increase.
Test hypothesis. You can use the average resting heart rate from the previous experiment. If you do an experiment with an increase in physical activity like jumping jacks, then your data will reflect an increase in heart rate because the body requires more energy, which requires more oxygen, increasing the overall flow of blood in the body.
Support or refute the hypothesis based on the results. The hypothesis is supported if it aligns with the observed results. The hypothesis is refuted if the results don’t match the statement based on the variables.
Testing more than one variable at a time makes it difficult to interpret the results and support or refute the hypothesis. With one variable, the results can be associated with changes to that variable. To get the most reliable data to support or refute a hypothesis, an experiment should be completed several times to see if the results show the same trends.
Explanation:
Penn Foster
Which color of light does chlorophyll b absorb more of than any other color?
Answer:
Blue and Red
Explanation:
The highest spike of chlorophyll B on this graph is between 400 and 500nm, making it a shade of blue. The second spike is between 600 and 700nm, making it a shade of orange-red.
the answer is blue\///////
A water strider (which can walk on water)has legs that are coated with a hydrophobic substance. What might be the benefit? What would happen if the substance were hydrophilic?
Answer:
The water striders are the species, which are about half an inch in length and exhibiting a thin body with three legs set. The legs of water striders exhibit small hairs, which helps in repelling water and holding air. The water striders by repelling water stand on the surface of the water and the captivated air permit them to float and move readily.
The legs of water striders are coated with hydrophobic substances, which helps in repelling water and assists in keeping the terminals of the legs from getting coated with water. In case, if the legs of the species were coated with a hydrophilic substance, then water would be drawn up by the legs and would make the striders break through the surface and thus would have a tough time to walk on water.
the process by which water boils into a steam is
Answer:
Hey hey your answer is evaporation
Answer:
Your answer is evaporation.
Explanation:
The rate of change of water into water vapour is called evaporation. For example, heating if water into water vapour.
Hope this helps....
Have a nice day!!!!
Why is digestion of fats difficult as compared to that of other nutrients?
This is because fats are insoluble in water and therefore are more difficult to digest than any other nutrients. They also present as large globules.
Hope that helped!!! k
Answer:
Fats take longer time to digest than carbohydrates. Fats can't be digested easily as its insoluble in water and are presented as large globules. The bile juice that gets secreted breaks down the fat from bigger droplets into smaller ones.
According to the theory of plate tectonics,which is one feature that plates carry?
Answer:
According to the theory of plate tectonics, seafloor features do plates carry.
Explanation:
There are many rough spots which can no longer hold, the sudden release of the built-up motion releases, and the sudden movement under the sea floor causes a submarine earthquake in the area.
Answer:
seafloor
Explanation :).
One side of your face is identical to the other side. You are _____. radially symmetrical asymmetrical bilaterally symmetrica
Answer:
For the answer to the question above, asking if One side of your face is identical to the other side. Then you are bilaterally symmetrical.
I hope my answer helped you. Feel free to ask more questions. Have a nice day!
Explanation:
Answer:
Bilaterally symmetrical
Explanation:
From my understanding, radially symmetrical means identical halves around the central axis.
Asymmetrical means not symmetrical at all
Leaving us with Bilaterally symmetrical, which is basically identical parts but as right and left.
That's the best i can explain so there is a diagram to help understand.
describe the direction of dna replication and why that is important
Answer: Roles of DNA polymerases and other replication enzymes. ... which require a template and a primer (starter) and synthesize DNA in the 5' to 3' direction. ... Topoisomerase also plays an important maintenance role during DNA replication.
Explanation:
hard to explain
What is:
a) Metamorphosis
b) Photosynthesis
c) Plant cycle
d) Absorption
e) Menustration
f) Sex.
Accurate answers please.
Answer:
a) Metamorphosis is a process by which an animal develops after birth including change in body structure.
b) Photosynthesis: this is the process used by plants to make their food.
c) Plant cycle: the generation and process/the adopted way in which plants grow.
d) Absorption is the ability for a light object/surface to be able to soak/take in something.
e) This is when a woman sees her monthly cycle/discharge of blood in a woman.(stage of puberty).
f) Sex is when someone have sexual intercourse/gender.
Explanation:
Hope they help.
what are the major groups of animals and how to they differ
Functions of the large intestine include Select one: A. most of the chemical breakdown of food. B. absorption of bile salts. C. secretion of vitamins. D. reabsorption of water and compaction of feces. E. production of gas to move waste toward the rectum.
I'm afraid brainly won't let me upload the answer so I attached it to a file.
It appears that your answer contains either a link or inappropriate words. Please correct and submit again!
What are two ways that society affects the progress of science?
Answer:
Technology usually affects society more directly than science because it solves practical problems and serves human needs (and may create new problems and needs). In contrast, science affects society mainly by stimulating and satisfying people's curiosity and occasionally by enlarging or challenging.
Explanation:
Drag each label to the correct location on the chart. Classify each process as weathering or erosion. PLEASE HELP me (I'm stuck) NO homo THOO
Lets do numbering of the labels to make labelling clear.
1. The Colorado River carves land in Arizona to form the Grand Canyon.
2. Cracks form in a sandstone wall surrounding a house.
3. A marble statue near the science museum is changing color due to rainfall.
4. After a rainstorm, soil and rock pieces litter the roadways.
5. The sand dunes in the Sahara Desert are changing shape.
Answer:
Weathering:
2. Cracks form in a sandstone wall surrounding a house.
3.A marble statue near the science museum is changing color due to rainfall.
Erosion:
1. The Colorado River carves land in Arizona to form the Grand Canyon.
4. After a rainstorm, soil and rock pieces litter the roadways.
5. The sand dunes in the Sahara Desert are changing shape.
Explanation:
Weathering and erosion, in both the processes rocks are broken down into particles but both the processes are different from each other. Weathering can be physical, chemical or biological process in which rock particles degrade without any movement while erosion is purely a movement of sediments in which particles move from one place to another under the influence of water and wind.
So, on the basis of this difference we can classify each label to the correct location:
Weathering (no movement of particles after degradation):
2. Cracks in a sandstone wall of a house.
3. Changing color of marble statue due to rainfall.
Erosion (Movement of particles from one place to another):
1. Formation of Grand Canyon, when the Colorado River carves land in Arizona.
4. Soil and rock pieces litter on roadways after rainstorms.
5. Changing shape of dunes in sahara desert.
Answer:
weathering - colorado river carves land in arizona to form the grand canyon. cracks form in a sandstone wall surrounding a house. a marble statue near the science museum is changing color due to rainfall
erosion - after a rainstorm, soil and rock piees litter the roadways. the sand dunes in the sahara desert are changing shape.
Explanation:
