When performing the streak for isolation technique, your result is unexpected: There is only growth obtained in quadrant 1. The growth observed in quadrant 1 is as expected, heavy with no isolated colonies. However, no growth is visible in any other quadrants.
Which of the following errors could explain this unexpected result?
A) The loop did not cross into quadrant 1 when streaking quadrant 2
B) You forgot to flame the loop in between quadrants
C) All of the errors listed here could be responsible for this unexpected result
D) Not enough bacteria was obtained from the starting culture when streaking quadrant 1
Answer:
A) The loop did not cross into quadrant 1 when streaking quadrant 2
Explanation:
The streak for isolation technique is a method used to get isolated bacterial colonies. This technique consists of, in a petri dish with culture medium, where, with the help of an inoculation loop, the bacteria are scratched on one side of the dish. This side is called the first quadrant. This inoculation loop must then cross with the first quadrant and be dragged to the second quadrant, where new lines must be made. This allows a part of the bacteria from the first quadrant to be carried over to the second. The inoculation loop must cross the second quadrant again to inoculate the third quadrant, and so on.
In this case, we can see that for bacterial colonies to grow in all quadrants, it is essential that the loop crosses in the first quadrant to cross out the second quadrant. If not, only the first quadrant will have bacterial colonies.
Answer:
A) The loop did not cross into quadrant 1 when streaking quadrant 2
Explanation:
There are many different techniques to isolate bacteria populations. Using solid media such as agar, you can perform the streak for isolation technique.
What you want to do by using this technique is to get an isolated colony of the bacteria of interest. And to get it, you need to dilute a sample or inoculum of bacteria as much as possible by streaking it. Every time you do it, you take fewer amounts of cells from the original sample, separating them each time more, to the point of having only one single cell apart by a few millimeters from another cell. The isolated cell divides and forms a new pure colony.
So basically, you need to imaginary divide the agar plate into four quadrants.
You sterilize the loop carefully and take a sample of bacteria, trying to get the smallest amount of inoculum. You will apply the loop with the sample in quadrant one and spread it. You close the plate and turn it, placing the second quadrant in front of you. You sterilize the loop again on the flame and let it cool. You perform the same motion in quadrant two but carefully touching the edge of quadrant one, so you can take some of the cells that you have already spread on it. Once you spread quadrant two, you close the plate and turn it again, so quadrant three is in front of you. You sterilize the loop again on the flame and let it cool. You perform the same motion in quadrant three but carefully touching the edge of quadrant two. Close and rotate the plate. You sterilize the loop and repeat the same motion in the last quadrant. Close the plate and take it to incubation. Finally, you put the loop on the flame for the last time.The importance of extending the streaks into the anterior quadrant is to take a few cells from there and to spread them in the following quadrant. In this way, you are diluting the original inoculum, and separating the cells each time more. The fourth quadrant should have a few isolated cells that will reproduce and form a pure colony. If you do not touch the anterior quadrant while streaking, you will not have any cell in the quadrant, and you will not observe any colony after the incubation. The importance of sterilizing the loop every time you change the quadrant is to avoid contamination with other species. If you do not flame the loop, the result will be too many colonies of different species, probably touching themselves, in each quadrant.………………………………………………………………….
whats with the dots ._.
If a human has an X and a Y chromosome pair, they are
The organ that controls your internal clock is called...
Answer:
The circadian biological clock is controlled by a part of the brain called the Suprachiasmatic Nucleus
Explanation:
That should be right
Please help!!
Why doesn't cloud formation take
place until the dew-point temperature is
reached?
Answer:
Clouds form when air reaches its dew point, the temperature when the air is saturated. This can happen in two ways. First, the air temperature can stay the same while the humidity increases. This is common in locations that are warm and humid.
Explanation:
Answer: The moisture in the cloud affects the weather.
Explanation:
thats why
The total magnification produced from a 15x ocular and a 4x objective would be
If the velocity of a can increases from 30 ms-1 to 90 ms -1, the kinetic energy
increases by
a. 8 times
b. 9 times
c. 7 times
d. 6 times
Which of these provides the best evidence for the plate tectonic theory?
The rise of magma by the convergence of earths plates
The destruction of earths magnetic field by the rotation of earths core
The variations in the age of rocks at different distances from the mid ocean ridges
The difference in the shapes of the Atlantic ridge and the coastlines of continents
Answer: C
Hope this helps!
trình bày cơ chế hấp thụ và chuyển hóa lipid từ đường tiêu hóa ở người?
Which of these is true for a fertilized egg?
O
A. It has DNA from both parents.
O B. It has a haploid number of chromosomes. .
O C. It has DNA but no chromosomes.
O D. It has too many chromosomes until it splits.
Here can you help me on this?
Answer:
Selective breeding
Selective breeding is when u choose 2 organisms with certain desirable characteristics and bread then together
Animals are selectively bread 4 many reasons
- To have a higher yield (meat, milk, eggs)
- Be able to run faster
what are the three strategies that the community could place to work with governmental structures to stop illegal dumping
Answer:
Illegal Dumping has gotten out of hand. According to the Los Angeles County Public Works, “People usually dump illegally to avoid collection and disposal fees, or because they believe proper disposal is just ‘too much trouble’.” This is very unfortunate for our communities who receive the negative consequences of higher taxes for cleanup, environmental hazards, and a breeding ground for rats.
The cost of a one-time cleanup and detoxing of an area can cost thousands of dollars. But to leave the mess is just not an option. The best option is to stop the illegal dumping before it happens, preventing the cost of cleanup, preventing the chemicals and toxins from entering the ground water, and preventing the rats and mosquitoes from breeding. The best areas to live are communities that care about their community! So, what can a community do to prevent illegal dumping?
Here are some key points to help deter illegal dumping:
Educate the public through the schools and through community awareness groups about the costs, chemical hazards and dangers incurred by illegal dumping
Create safe, public-friendly waste disposal options and advertise them
Create laws that impose stiff fines for the perpetrators and advertise these stiff fines
Use Illegal Dumping Cameras to catch the perpetrators in the act
Use Social Media to ask the public to identify the perpetrators
Follow through with quick clean up
These steps will invite the citizens to be involved and help deter the criminal activity of illegal dumping within your community.
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Why is the temperature at the extremities, such as the fingers,
sometimes colder than the core body temperature?
O A. So that less energy is lost in cold environments.
OB. The fingers need to be colder to protect the durability of the nails.
C. The fingers do not have thermoregulation mechanisms.
D. So that more energy is lost in cold environments.
Answer:
A. so that less energy is lost in cold environments.
Explanation:
When it’s cold outside, your body makes sure to keep the blood flowing to your core and vital organs to keep them warm. This can change the amount of blood flow to your hands and feet, making them feel cold. This is normal. The blood vessels in your hands and feet constrict (spasm) when it’s cold, to prevent heat loss from your core
this is the answer for
'select the correct location on the image.
Where are the photoreceptors located inside a human eye?'
nice I'm going to do this with all the answers i have now
what are the characteristics of normal cells and cancerous cells?
Normal cells stop growing (reproducing) when enough cells are present. For example, if cells are being produced to repair a cut in the skin, new cells are no longer produced when there are enough cells present to fill the hole (when the repair work is done).
In contrast, cancer cells don’t stop growing when there are enough cells present. This continued growth often results in a tumor (a cluster of cancer cells) being formed.
science
the imaginary lines which divide the earth into areas of 15º are called
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[tex]\color{red}{⚠TheQueenNoNeedAKing⚠} [/tex]
[tex]\color{Violet}\rm{Answer:}[/tex]
longitude lines
longitude lines. Imaginary lines, also called meridians, running vertically around the globe. Unlike latitude lines, longitude lines are not parallel. Meridians meet at the poles and are widest apart at the equator. Zero degrees longitude (0) is called the prime meridian.[tex]\color{Violet}\rm{☘︎Hopeithelps!}[/tex]
__________________________________
“But you, my Lord, are a God of compassion and mercy; you are very patient and full of faithful love.” — Psalm 86:15 ❤__________________________________
Which is the word equation for photosynthesis?
Answer:
carbon dioxide + water + sunlight + chlorophyll → glucose + oxygen
Explanation:
I hope this helps in any way :)
Fat cells are expandable. How does this structure relate to a fat cell's function?
A) Fat cells store energy for the body to use later, so being
expandable would help with storage.
B) Fat cells burn energy quickly when other food source is available, so being expandable would help with the rapid burn.
C) Fall cells protect organs, so being expandable can help with cushioning.
D) Fat cells do not expand
Fat cells burn energy quickly when other food source is available, so being expandable would help with the rapid burn.
The relationship between the expandability of fat cells and a fat cell's function is ; ( A ) Fat cells store energy for the body to use later, so being expandable would help with storage.
Fat cells specialized for the storage of energy in human body is the Adipose tissue which can expand between 60 to 70% of the weight of the human body in response to changes in the energy balance of the body.
Adipose tissues store energy in form of triglycerides and in order to store more energy for later use the Adipose would need to be expandable to accommodate the required amount of energy.
Hence we can conclude that the relationship between the expandability of fat cells and a fat cells' function is Fat cells store energy for the body to use later, so being expandable would help with storage.
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Refer to the given diagram to answer Question 9
Y-ANTIBODIES
X-WBC
V-RBC
W-PLATELETS
QUESTION 9
ry
Which of the labelled structures in the diagram match the function below.
1.
Contains haemoglobin
II.
Carries out phagocytes
III.
Produces antibodies
J.
Involves in blood clotting
IV
A.
V
Y
W
В.
W
V
Y
С.
V
Y
X
w
D
Y
X
W
Answer:
C
Explanation:
Answer c contains all the list listed
The differences in beak shape are examples of:
Answer:
BIOLOGICAL ADAPTATION
Explanation:
Bird beaks are textbook examples of BIOLOGICAL adaptation to diet, but their shapes are also controlled by genetic and developmental histories.
Answer: The first one is bacterial because it mutates very quickly compared to humans and the second one is biological adaptation
Hope it helps you if not sorry
Explanation:
eagles have specially adapted feet and talons to help them out. A series of bumps on the bottom of their feet -- known as spicules -- help them hold on to their prey during flight. They also have razor-sharp talons that they use to grab their prey, kill it and tear into.
From what you know of tonicity, what can you say about the plant cells and the solutions in the test tubes
Answer:
Tonicity is the relative amount of solutes that is dissolved in solution which determine the direction and level of diffusion.
Explanation:
Tonicity is the relative amount of solutes that is dissolved in solution which determine the direction and level of diffusion. There are three types of tonicity i.e. hypertonic, hypotonic and isotonic solution. If a cell is placed in a hypertonic solution, water will leave the cell, and the cell will shrink due to more solute in the external environment. In an isotonic environment, there is no water movement occurs, so there is no change in the size of the cell. When a cell is placed in a hypotonic environment, water will enter the cell, and the cell will swell. due to lower amount of water present inside the cell.
Photosynthesis occurs with the help of
A. CO2 and Water
B. SO2 and water
C. Oxygen and CO2
D. Oxygen and water
Explanation:
(A) = Carbon dioxide and water. Because, photosynthesis is the process by which green plants manufacturer their food by combining water and carbon dioxide in the process of sunlight energy trapped by chlorophyll to produce carbohydrate and released oxygen. from the above definition we see that, Photosynthesis cannot occur without water and carbon dioxide present
difference between enzyme and inorganic catalysts
Answer:
Enzymes catalyze a reaction which in presence of a catalyst proceeds the reaction faster. Inorganic catalysts promote a chemical reaction between many different reactants. Enzymes are proteinaceous in nature whereas inorganic catalysts are not proteinaceous in nature.
Explanation:
The_____
is like the ______
system of
the human body because they both_________.
Answer:
The cell wall is like the integumentary system of the human body because they both protect the interior from the external environment.
Explanation:
Which statement describes all stable ecosystems?
1) Herbivores provide energy for the autotrophs,
2) The populations of predators are dependent on
the populations of their prey.
3) The number of autotrophs equals the number of
heterotrophs.
4) Consumers synthesize ATP from light energy.
Stable ecosystem has the populations of predators are dependent on the populations of their prey of predators .
What is ecosystem?An ecosystem is a geographic area where plants, animals, and other organisms, as well as weather and landscape, work together to form a bubble of life.
Who are predators ?Predators are organisms that hunt and kill other organisms for food. The organisms that are consumed by the predators are known as the prey.
Stable ecosystem has the populations of predators are dependent on the populations of their prey of predators .
Hence, option 2 is correct
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Which of the following is not true regarding the establishment of a neuron's resting membrane potential?
a. Resting membrane permeability to Na+ is very low.
b. Ion pumps in the plasma membrane eject sodium ions as fast as they cross the membrane.
c. Electrical forces do not push sodium ions into the cell.
d. Chemical and electrical forces both favor sodium ions entering the cell.
e. The chemical gradient for potassium ions tends to drive them out of the cell.
Answer:
c
Explanation:
Which statement describes Mendel’s hypotheses regarding gametes?
A) gamete carries two genes for a trait.
B) gamete carries one allele for a gene.
C) gamete can carry multiple alleles for a trait.
D) Some gametes are dominant and some are recessive.
Answer:
The correct answer is B. A gamete carries one allele for a gene.
Explanation:
Gamete (also called sex cell or reproductive cell) is a haploid cell (having half number of chromosome as compared to the parent cell) that is produced through a cell division, termed as meiosis in sexually reproducing organisms.
According to the Law of segregation given by Gregor Mendel-
During the process of gamete formation, the two alleles of each gene segregate from one another so that a gamete carries one allele for a gene.
Thus, option B) is the right answer.
Answer:
B.
Explanation:
which of the following hypotheses can be tested with experiments? select all that apply
1.) a diet low in sugar reduces the risk for heart disease
2.) coffee increases subject performance on intelligence tests
3.) people that brush their teeth live longer than those who don't brush their teeth
4.) scientists will find a cure for cancer before the year 2020
I know that 4 isn't the answer so I selected the other three and it said I was wrong. isn't a hypotheses something that can be experimented on so can't all of the three have experiments If I'm making sense
Options 1 and 2 can be tested through experimental procedures.
A hypothesis is an explanation for a given phenomenon from the real world.A testable hypothesis is a plausible explanation that can be proved (or rejected) by an experimental and/or observational procedure. A well-designed experiment should have into account the following characteristics: randomization, replication and local control.Manipulation indicates that one variable (dependent variable) is purposefully changed by the scientist in the environment.The controls must be used to prevent non-controlled factors which might be influencing the outcomes of the experiment.Option 3: it is not possible to carry out an experiment to test this hypothesis.Option 4: it is not a hypothesis and a false anachronic statement (cancer is a multifactorial disease that currently still has not been cured).In conclusion, only Options 1 and 2 can be tested through experimental procedures.
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The process of photosynthesis ultimately converts light energy into -
what are the advantages of genetically modified plants
Answer:
advantages are of genetically modified plants are the desired traits it results in but also they well-grown fruits and vegitables will be plump, ripe and delicious.
Explanation:
