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
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:
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.
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?
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.
Change of a liquid to a gas is ___________.
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.
Muscle weakness is associated with Vit A/ Vit E/ Vit K/ Protein deficiency
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.
explain how the various specialiesed cells are modified to Cary out to their function 20mark
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
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:
What is gylcosylation
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.
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.
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.
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
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.
Answer:
very different than ducks do u want it is not the
I want answers please
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
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.
Answer:
both will concentrate in the vinegar layer because both are polar and Hbond with vinegar (an acid)
Explanation:
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.
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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The conversion of liquid water into gaseous water is called?
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.
. Calculate the 3 difference between food chain and food web
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:
Evalute paper bags versus poly bags on the following parameters strength, cost, reusability impact on environment
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.
Water droplets are pulled towards earth by ______________.
Plz help me with this question
Answer:
all the flowers would be pink
Explanation:
i took the test
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.
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.
function of graffian follicle
Answer:
It provides for the maturation and release of a fertilizable oocyte
Explanation:
let me know if you have any questions
Biological organization extends beyond the organism. Which group of terms would be included beyond organism in the same list
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
what is the full form of ATP?
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.”
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.
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.
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
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.
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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
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.
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.
Answer:
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fk.ydj.td.jtd.sjtd
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Explanation:
hhm y chupapico
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
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.
What could explain how
antibiotics harm bacteria without
hurting the human taking them?
Bodily energy Taoists cultivate within themselves is called:
A. Jen
B. Tao
C. Wu
D. Chi
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 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
Answer:
Explanation:
Carbon dioxide
