A sample from a stock of a bacterial colony in liquid media was diluted by a factor of 106, and 2 ml of this dilution was spread on a Petri dish of solidified media. 56 colonies were observed. What was the concentration of bacteria of the initial stock?

Answers

Answer 1

Answer:

28 × 10⁶ colonies/ml

Explanation:

Let C be the concentration of bacterial in the initial stock. When it is diluted by a factor of 10⁶, the new concentration is C' = C/10⁶.

When 2 ml of this concentration is spread on a Petri dish of solidified media, 56 colonies were produced. The number of colonies, n after spreading the 2 ml of C' is C' × 2 ml = 2C' = 2C/10⁶.

So, n = 2C/10⁶.

Since the number of colonies after spreading on a Petri dish of solidified media is 56, n = 56 colonies.

So, 2C/10⁶ = 56

Making C subject of the formula, we have

C = 56 × 10⁶/2

C = 28 × 10⁶ colonies/ml

So, the initial concentration of bacteria is 28 × 10⁶ colonies/ml


Related Questions

The numbers of each genotype of mice in the questions above shows that there are more dark mice living on the dark substrate and more light mice living on the light colored substrate. But when we consider comparative overall fitness for the entire area, which fur color seems to have the greatest overall selective advantage, and why

Answers

Answer:

Dark colour.

Explanation:

Dark fur color seems to have the greatest selective advantage because of their hard physical body which occurs due to extreme environmental conditions. The dark colour of mice occurs due to the high intensity of sunlight which increases melanin in their skin. These dark colour mice pass through a very hard and extreme environmental conditions so that's why Dark fur color seems to have the greatest selective advantage.

Phân tích các quy luật hoạt động thần kinh cấp cao ở trẻ và vận dụng trong thiết lập thói quen học tập và kỉ luật ở học sinh tiểu học.

Answers

Answer:

very different than ducks do u want it is not the

What is gylcosylation

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Glycosylation is the reaction in which a carbohydrate, i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule in order to form a glycoconjugate. In biology, glycosylation usually refers to an enzyme-catalysed reaction, whereas glycation may refer to a non-enzymatic reaction.

The answer is:

Glycosylation is a biochemical process where a glycan attaches to a protein, a lipid, or other organic molecule, especially through the catalytic action of certain enzymes.

I want answers please ​

Answers

Explanation:

1.arm&base

2.a shutter controlled by a lever

3.Nosepiece,objective lenses,stage clips

6. 100X.....(this means that the image being viewed will appear to be 100 times its actual size

. Calculate the 3 difference between food chain and food web

Answers

FOOD CHAIN AND FOOD WEB

A linear pathway showing the flow of energy . A multitude of networks showing the flow of energy

An organism of higher level trophic feeds on a specific organism of lower trophic level An organism of higher trophic level has access to more members of a lower trophic level.

Has no effect on the adaptability and competitiveness of organisms. Has a role in improving the adaptability and competitiveness of an organism.

Answer:

A linear pathway showing the flow of energy . A multitude of networks showing the flow of energy

An organism of higher level trophic feeds on a specific organism of lower trophic level An organism of higher trophic level has access to more members of a lower trophic level.

Has no effect on the adaptability and competitiveness of organisms. Has a role in improving the adaptability and competitiveness of an organism

Explanation:

b. Bobcats are another predator of snowshoe hare. If a population of bobcats immigrates to the
area, how is this likely to affect the habitat's carrying capacities for hare and lynx?

Answers

Answer:

Decrease population and carrying capacity.

Explanation:

If a population of bobcats immigrates to the  area, the population of hare and lynx decreases that also affect the habitat's carrying capacities for hare and lynx because bobcats feed on both hare and lynx. Bobcats are very aggressive in nature, and has an aggressive hunting style. With these characteristics, the bobcats can hunt both hare and lynx which leads to decrease in population and carrying capacity.

In April 1990, the El Paso County (Colorado) Health Department recognized an outbreak of drug-resistant gonorrhea in Colorado Springs. 56 cases of penicillin- resistant Neisseria gonorrheae occurred from December 1989 through March 1991. To gather information about the outbreak, 410 persons related through a densely connected set of social or sexual associations were interviewed. What can public health workers tell individuals in this network to stop the spread of Gonorrhea in this population?
a) Preventive treatment with penicillin will prevent Gonorrhea infection in individuals not already infected.
b) Only individuals with symptoms should seek medical screening since all cases of Gonorrhea are associated with symptoms.
c) Condoms will not prevent the spread of Gonorrhea. Gonorrhea can spread from an infected mother to a fetus.
d) Gonorrhea is more prevalent in individuals 24 years and older.

Answers

Answer:

c) Condoms will not prevent the spread of Gonorrhea. Gonorrhea can spread from an infected mother to a fetus.

Explanation:

To prevent the spread of infection, it is important that healthcare professionals inform people about ways to protect themselves against infection. In addition, it is important that health professionals inform the dangers that this infection can cause, such as symptoms and rapid transmission, which can even happen from mother to fetus. On how to protect themselves, health professionals can say that the use of condoms is the most efficient form of protection.


What component of Earth's atmosphere exists entirely as a result of photosynthesis?
oxygen pas
n mas
O water vapor
O nitrogen gas
O carbon dioxide gas

Answers

Answer:

Explanation:

Carbon dioxide

The last one is correct
Hope its help for your questions

PLEASE HELP ME!!!! I am stuck.
The frequency of tasters and nontasters of PTC varies among populations. (Answer ALL questions)
- In population A, 94 percent of people are tasters (an autosomal dominant trait)
and 6 percent are nontasters.
- In population B, tasters are 75 percent and nontasters 25 percent.
- In population C, tasters are 91 percent and nontasters are 9 percent.

1. Calculate the frequency of the dominant (T) allele for PTC tasting in population A.
2. Calculate the frequency of the recessive (t) allele for nontasting in population A.
3. Calculate the frequency of the dominant (T) allele for PTC tasting in population B.
4. Calculate the frequency of the recessive (t) allele for nontasting in population B.
5. Calculate the frequency of the dominant (T) allele for PTC tasting in population C.
6. Calculate the frequency of the recessive (t) allele for nontasting in population C.
7. Assuming that Hardy-Weinberg conditions apply, determine the TT frequency in population A.
8. Assuming that Hardy-Weinberg conditions apply, determine the Tt frequency in population A.
9. Assuming that Hardy-Weinberg conditions apply, determine the tt frequency in population A.
10. Assuming that Hardy-Weinberg conditions apply, determine the TT frequency in population B.
11. Assuming that Hardy-Weinberg conditions apply, determine the Tt frequency in population B.
12. Assuming that Hardy-Weinberg conditions apply, determine the tt frequency in population B.
13. Assuming that Hardy-Weinberg conditions apply, determine the TT frequency in population C.
14. Assuming that Hardy-Weinberg conditions apply, determine the Tt frequency in population C.
15. Assuming that Hardy-Weinberg conditions apply, determine the tt frequency in population C.

Answers

Answer:

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Explanation:

hhm y chupapico

Given the enormous heterogeneity of antigen receptors expressed on the populations of naive B and T lymphocytes, the adaptive immune response relies on a process whereby the rare lymphocyte that binds to the antigen is first induced to proliferate, before it can perform its effector function. For B cells, there is a clever mechanism that ensures that the specificity of the antibody secreted by the plasma cell will recognize the same pathogen that initially stimulated the B cell antigen receptor and induced B cell proliferation. This mechanism is:

Answers

Answer:

The naïve B cell expresses a membrane-bound form of the antibody as a receptor and secretes that same antibody when it differentiates into a plasma cell.

Explanation:

Naive B cell is a type of B cell that has still not been exposed to the antigen. The B cell receptors (BCRs) are transmembrane proteins composed of 1-a surface immunoglobulin molecule capable of recognizing the antigen, and 2-two transmembrane subunits that transduce the signal. When a B cell binds to antigen with its BCR, the B cell will proliferate and differentiate into a plasma cell. This plasma cell then releases antibodies, which are soluble forms of the BCR where the transmembrane domain that anchors the antibody protein to the membrane of the B cell is eliminated.

Evalute paper bags versus poly bags on the following parameters strength, cost, reusability impact on environment ​

Answers

Answer:

Poly bags are more stronger than paper bags.

Explanation:

Poly bags are more stronger than paper bags due to the use of materials in it while on the other hand, cost of production on the poly bags is less than paper bags. Poly bags can't be reuse whereas the paper bags can be used. The poly bags causes more pollution in the environment due to its non-degradable nature as compared to paper bags that degrades easily and has a good impact on environment.

The conversion of liquid water into gaseous water is called?

Answers

Answer:

vapourization

Explanation:

When the water is heated, it changes into water vapour which is called vapourization or sometimes we can also call it evaporation.

function of graffian follicle

Answers

Answer:

It provides for the maturation and release of a fertilizable oocyte

Explanation:

let me know if you have any questions

explain how the various specialiesed cells are modified to Cary out to their function 20mark​

Answers

Sperm cell; has acrosome containing lytic enzymes; that digest the egg membranes for penetration during fertilization; has a long tail; containing numerous mitochondria; to generate maximum energy for propulsion/swimming in the vaginal fluid after ejaculation; Red blood cells; are flattened, circular/spherical biconcave in shape; to increase the surface area for packaging of haemoglobin; has haemoglobin; that combines with respiratory gases; for transport to and from body tissues; White blood cells; are amoeboid in shape hence able to change shape; to engulf pathogens through phagocytosis; lymphocytes produce antibodies to fight pathogens; Nerve cell; has extensions/dentrites; to receive and send information for sensation; Ciliated epithelial cells; have cilia for propulsion of mucus that traps dust and micro-organisms in the respiratory tract; Muscle cells; elongated, striated and contractile; to bring about movement; Plant cells: Guard cells; bean-shaped; to regulate the size of the stomata allowing gaseous exchange; and control water loss; has chloroplasts with chlorophyll; for photosynthesis; Root hair cell; elongated; thin-walled; with dense cytoplasm for absorption of water and mineral salts; Epidermal cell; thin; for protection of inner tissues from mechanical and micro-organism attack; Palisade cell; contains numerous chloroplasts with chlorophyll; for photosynthesis; elongated; to increase surface area for trapping maximum amounts of light energy; Meristematic cell; thinwalled; with dense cytoplasm; for primary and secondary growth

Muscle weakness is associated with Vit A/ Vit E/ Vit K/ Protein deficiency

Answers

Sorry if it wrong but I think it is Nerves, or blood vessels

Answer:

Low vitamin E levels may result in Muscle weakness: for the central nervous system, vitamin E is vital. It is one of the major antioxidants in the body and a shortage causes oxidative stress that can lead to weakening in muscles.

Explanation:

The body needs to work with vitamin E and become a necessary vitamin. It is fat-soluble, thus it has to be effectively absorbed in fat from the food. Before being released to the bloodstream for usage, vitamin E is mostly kept in the liver.

The deficiency is unusual and usually caused by an understatement. There are also modest levels of preterm newborns.

Eight kinds of vitamins exist. A blood test allows a physician to know how much a person has of an alpha-tocopherol form. Use this information to establish if the total vitamin E level of a person is present.

A standard level is typically between 5.5 and 17 milligrams (mg/L) per litre. For premature infants and youngsters under 17 years, the typical range may be different. The Normal scope may also be somewhat different amongst laboratories.

If an adult has less than 4 mg/L of vitamin E in his or her blood, supplementation is usually necessary.

Under normal conditions the sympathetic division is usually active in the body resting heart rates are influenced by nor epinephrine the parasympathetic system keeps heart rate lower than the heart would beat on its own. all of the above are true

Answers

Answer:

the parasympathetic system keeps heart rate lower than the heart would beat on its own.  

Explanation:

The parasympathetic nervous system (PNS) is one division of the autonomic nervous system. The vagus (parasympathetic) nerves that innervate the heart release acetylcholine in order to slow the heart rate by decreasing the slope of the pacemaker potential. Acetylcholine activates a type of G-coupled protein receptor known as muscarinic receptors, allowing for a parasympathetic reaction in the cardiovascular system (where these receptors are expressed), and thereby decreasing cardiac output by inhibiting heart rate. During rest, PNS predominates and controls the heart rate at a resting rate of 65-80 beats/minute (bpm), if parasympathetic nerves to the heart are cut, then the heart beats at its own rate of about 100 bpm.

Plz help me with this question

Answers

Answer:

all the flowers would be pink

Explanation:

i took the test

what is the full form of ATP?​

Answers

Answer:

ATP stands for Adenosine triphosphate, an organic molecule responsible for driving nearly all cellular mechanisms and processes in living organisms. Hence, biologists often refer to ATP as the “energy currency of the cell.”

Put the following steps of Meiosis in the correct order:

I. The cell divides into 2 daughter cells
II. Homologous chromosomes pair up in the center of the cell
III. Spindle fibers separate homologous chromosomes
IV. Chromosomes become shorter and thicker
A. I, II, III, IV
B. IV, III, II, I
C. II, III, I, IV
D. IV, II, III, I

Answers

C.
Because first thing that happens in meiosis is the homologous pairs come in the center of the cell. Without that happening first, the cell can’t divide into 2 daughter cells, so it is NOT option A.
Chromosomes will become shorter and thicker at the end so the only option that remains is C.
Homologous chromosomes pair up in the center of the cell.Spindle fibers separate homologous chromosomes.The cell divides into 2 daughter cells.Chromosomes become shorter and thicker.

What is Meiosis

Meiosis  (listen); from Ancient Greek'lessening', since it is a reductional division) is a special type of cell division of germ cells in reproducing organisms that produce the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately result in four cells with only one copy of each chromosome (haploid). Additionally, before the division, genetic material from the paternal and maternal copies of each chromosome is crossed over, creating new combinations of code on each chromosome. Later on, during fertilization, the haploid cells produced by meiosis between a male and female will fuse to create a cell with two copies of each chromosome again, the zygote.

Errors in meiosis resulting in aneuploidy (an abnormal number of chromosomes) are the leading known cause of miscarriage and the most frequent genetic cause of developmental disabilities.

Learn more about Meiosis

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The change that occurs at point C could be caused by Multiple choice question. A) increased predation by wolves. B) a wet year with increased vegetative growth. C) increased competition from moose herds. D) a dry year with decreased vegetative growth.

Answers

Answer:

The answer is "Option B"

Explanation:

A wet season with increased plant growth is indicated by the fact that the population of Elks from beginning point C attained maximum population size (K100) and remained stable until point D. That's why the difference at point C could be due to the a wet year still higher plant growth.

As you read in this chapter, fungi have long formed symbiotic associations with plants and with algae. How may these two types of associations lead to emergent properties in biological communities

Answers

Answer:

Fungi show symbiotic association with algae and plants. With plants, they thrive as endophytes in a form of the symbiotic association. This symbiotic association results in the emergence of novel characteristics in the world of biology.  

The lichens function as a tool in finding the quality of air, as they grow in the environment containing good air quality. The tolerance towards heat is another characteristic. Some of the endophytes are witnessed in the plants, which grow in very hot conditions.  

At such conditions, no fungi or plant can thrive, however, in the symbiotic association, they possess the tendency to thrive. If one tries to separate them, it results in the death of both.    

Explanation:

Bodily energy Taoists cultivate within themselves is called:
A. Jen
B. Tao
C. Wu
D. Chi

Answers

Answer:

The correct answer is - D. Chi.

Explanation:

Taoist is a Chinese origin tradition that is spiritual and philosophical and focuses on living in harmony with, the source, patter, and substance of everything exists called Tao.

They believe that Chi is the bodily energy one needs to cultivate within oneself it is known as the energy of life and it translates as cultivation of energy. One can cultivate by relaxing and focusing on the body, abdominal breathing, connect to the earth and believe in chi.

What could explain how
antibiotics harm bacteria without
hurting the human taking them?

Answers

Because the antibiotics fight the bad bacteria that your body doesn’t need versus fighting the good bacteria that your body does need.

Sucrose and monosodium glutamate (MSG) are added to a salad dressing made of vinegar and oil. If the mixture is then shaken, it will eventually separate into two phases. After this phase separation, where will most of the sucrose and MSG be located?
a. Both will concentrate in the vinegar.
b. Both will concentrate in the oil.
c. Both will concentrate at the interface between the two phases.
d. Sucrose will concentrate in the oil, and MSG will concentrate in the vinegar.
e. Sucrose will concentrate in the vinegar, and MSG will concentrate in the oil.

Answers

Answer:

both will concentrate in the vinegar layer because both are polar and Hbond with vinegar (an acid)

Explanation:

Change of a liquid to a gas is ___________.

Answers

Answer:

Condensation. think about I, if you see fog on a lake or pond, that's condensation, if you see water droplets on the side of your cold beverage, that's condensation.

Water droplets are pulled towards earth by ______________.

Answers

Gravity is the answer

Which statement about the genetic code is false?
A. There is no punctuation or spacing between codons.
B. Codons are composed of sets of three nucleotides.
C. Every amino acid is specified by a single codon.
D. The genetic code is almost universal, but not quite.

Answers

————C————

Step by step explaintion:
trust me i’m right lol

The statement 'every amino acid is specified by a single codon' about the genetic code is FALSE (Option C).

The genetic code refers to the process by which the heritable information is passed from the DNA sequence to RNA during transcription, and then from RNA to protein during translation.

The genetic code is said to be redundant because there are amino acids that can be encoded by more than one codon.

For example, the amino acid leucine can be specified by four different codons (CUU, CUC, CUA, and CUG).

In conclusion, the statement 'every amino acid is specified by a single codon' about the genetic code is FALSE (Option C).

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What happened to the California Condors?
A. They went extinct in 2002 due to destruction of their habitat.
B. There were only 149 left in the 1980's but even with a captive breeding
program they went extinct in 2010.
C. They went extinct in the 1700's but remains from a well preserved skeleton
contained enough to DNA to begin cloning them.
D. In 1985 there were only 9 left, but a captive breeding program has increased
their number to 300.

Answers

Answer:

B

Explanation:

California Condors have been in decline about as long as European Settlements began to spread across North America. These birds have been on the U.S endangered species list since 1967 and were near extinction when their captive-breeding program began. California Condors also mature and reproduce slowly.

6.Two apparently normal parents have a daughter who suffers from agammaglobulinemia (AGG), an inherited defect of the immune system. Use a Punnett square to show how two normal parents could have a child afflicted with an inherited disease. What are the parents' genotypes

Answers

Answer:

See the answer below

Explanation:

For two normal parents to have produced a daughter who suffers from AGG, it means the disorder is an autosomal recessive trait. In order words, it means the parents are both carrying the allele for the disorder in recessive form.

Let us assume that the allele for the disorder is represented by b, meaning that the alternate form would be B. Both parents will have the genotype Bb and will both appear normal.

      Bb    x    Bb

    BB   Bb   Bb   bb

The affected child would be the one with bb genotype while the remaining children would appear normal. See the attached image for the Punnet's square analysis of the cross.

The genotypes of the parent would be heterozygous.

Biological organization extends beyond the organism. Which group of terms would be included beyond organism in the same list

Answers

Answer:

This question lacks options, the options are:

A. populations, communities, and ecosystems

B. DNA, RNA, and protein

C. Cells, tissues, and organs

The answer is A

Explanation:

The biological level of organization shows the organized build up of life from cellular level to organismal level. However, this organization goes beyond the organismal level. Individual species of organisms can assemble to form a POPULATION.

Likewise, populations of different species can coexist to form a COMMUNITY. The community of organisms can interact with their abiotic environment to form an ECOSYSTEM.

Therefore, the level of biological organization extends as follows:

populations → communities → ecosystems

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After examining the records of Theta Company for the month of October, the following information is obtained: Beginning cash balance $2,700 Cash receipts 56,000 Cash payments 36,000 Minimum cash balance 1,000 Loan repayments 10,000 Based on the given information, calculate Theta's cash surplus (deficiency) for the month of October. Angie used 4 apples and 5 strawberries in her fruit salad. Salim used 7 apples and 9 strawberries. Did Angie and Salim use the same ratio of apples to strawberries? If not, who used the greater ratio of apples to strawberries? When core body temperature rises, blood vessels in the skinget wider, allowing a larger volume of blood to flow near the skin surface. This is called:A. Negative feedbackB. VasodilationC. ShiveringD. Vasoconstriction Are these sentences in the correct verb form? If they're not what are the correct sentences rewritten? Thanks! PLEASE HELP WILL GIVE BRAILNLIEST! Find the value of x 8.the following one is considered as safety rule in laboratory1 pointnever eat or drink anything in the science labalways clean up when you have finished the experimentwear safety goggles while doing experimentsall the above short description about Madal your exceptional sense of duty is surely a feature to be praised... PLEASE ANSWER ASAP!!Which is the best example of a topic that is too broad?A. why US students who attend schools abroad tend to be more successfulB.the consequences of refusing to improve a science curriculumC. events during the eighteenth century that most affected the US school systemsD.the history of school systems in many of the states in the United StatesE.the importance of training teachers to differentiate education for students What is the equation of the line that is perpendicular to the line y = 2x + 5 andpasses through the point (-4, 2)? Rita said to me, "Where did you buy this pen?"(change into indirect speech) Accrued Product Warranty Fosters Manufacturing Co. warrants its products for one year. The estimated product warranty is 4% of sales. Assume that sales were $379,000 for January. On February 7, a customer received warranty repairs requiring $250 of parts and $105 of labor. a. Journalize the adjusting entry required at January 31, the end of the first month of the current fiscal year, to record the accrued product warranty.b. Journalize the entry to record the warranty work provided in February. Which phrase best completes the diagram showing the structure of statejudicial branches??Intermediateappellate courtsCourts of lastresortA. Federal courtsB. Trial courtsO C. Juvenile courtsD. Supreme courts Supply chain analysis of Coca-Cola in Vietnam. And draw lessons for other bottled water companies. If we ___________ that train, we shall have to leave now.are to catchcatchingto catchwere to catch Many talented teachers at Sunnydale High School resigned from their jobs in the past year. The Administrative President of the school board is in a fix and is unable to identify a reason for this attrition. The school pays competitive wages to its teachers and even gave them a pay hike recently. In this scenario, which of the following points should Sunnydale's Administrative President keep in mind when devising a solution to the problem?a. Money is the main reason people leave, so the school administration should give its employees a bonus along with the pay hike.b. When pay is competitive, other job factors become more important than the pay employees receive.c. Employees are bound to leave, and there is not much employers can do to retain them.d. Teachers usually leave their jobs because of involuntary turnover, so pay is not a major factor in their retention. define structure and function A movie theater has a seating capacity of 187. The theater charges $5.00 for children, $7.00 for students, and $12.00 of adults. There are half as many adults as there are children. If the total ticket sales was $ 1338, How many children, students, and adults attended?___ children attended.___ students attended.___ adults attended. WILL GIVE EXTRA POINTS NEED ANSWER What is one major personal weakness that both Josephine and Constantia share?A.They disobey every order their father gives them.B.They don't take control over their own lives.C.They don't pay attention to detail.D.They're very pushy with their opinions. Submit TestPrevious3Next Early Humans and the Neolithic Revolution: Mastery Test3Select the correct answer.What factor led civilizations to develop a division of labor?.a written languageOB.a small population size.simple government structuresfood surplusesOD.ResetNextWhat factor led civilizations to develop a division of labor