You do a serial dilution in the same manner as the one in the video. A plate with a sample volume of 10-6 mL produced 43 colonies. What was the original cell density (CFU)?

Answers

Answer 1

Answer: 43 x 10^6  CFU.

Explanation:

Plate count is a method used to determine the number of viable microorganisms in a sample. When the bacterial concentration is high, serial dilutions are carried out in a 1:10 sequence. Then, the dilutions are successive dilutions keeping the dilution factor constant at each step. Small aliquots of these dilutions are seeded in medium contained in a Petri dish where the bacteria grow forming colonies. Then the plates are incubated and colonies develop both within the agar and on the surface.

If the concentration of the seeded aliquot is too high, the bacteria will grow too much and it will not be possible to distinguish the colonies. However, if the concentration is very low, the number of colony forming units (CFU) may be very low and thus can be counted.

Colony forming units are calculated:

CFU = Number of colonies / (volume seeded on the plate * dilution).

The dilution is 10^-6, the number of colonies counted is 43, and usually the volume plated is 0.1 mL, so we replace that in the equation:

CFU= 43 / (0.1 mL * 10^-6)

CFU= 43000000 = 43 x 10^6


Related Questions

How does the cardiovascular system deliver nutrients and oxygen to all cells in the body via the flow of blood?

Answers

The heart, blood and blood vessels work together to service the cells of the body. Using the network of arteries, veins and capillaries, blood carries carbon dioxide to the lungs (for exhalation) and picks up oxygen. From the small intestine, the blood gathers food nutrients and delivers them to every cellular.

Help me really quick please

Answers

Answer:

a

Explanation:

potential energy is highest at its highest point

How do individual’s affect environmental systems?

Answers

Answer:

Humans impact the physical environment in many ways like overpopulation

Explanation: pollution, burning fossil fuels, and deforestation. Changes like these have triggered climate change, soil erosion, poor air quality, and undrinkable water. and many more ways.

Answer:

Humans impact the physical environment in many ways like overpopulation

Explanation:

pollution, burning fossil fuels, and deforestation. Changes like these have triggered climate change, soil erosion, poor air quality, and undrinkable water. and many more ways.

Match each term to the appropriate description.

Answers

Answer:

Have a great day!

Explanation:

The appropriate term for each description would be ecosystem, community, population, organism, and species respectively.

Definition of ecological terms?

An ecosystem is a community of all living organisms interacting with their environment as a system.

A community is a collection of different populations of organisms.

A population is a group of organisms of the same species capable of mating.

Species are a group of organisms that is capable of breeding to produce fertile offspring.

Thus, the term for each description would be ecosystem, community, population, organism, and species respectively.

More on ecological terms can be found here: https://brainly.com/question/13046612

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1. What do DNA Replication and Cell Division have in common?
2. Define Cell Differentiation in your own words.
3. Why are stem cells consjdered unique?

Answers

Answer:

1: During every cell division, a cell must duplicate its chromosomal DNA through a process called DNA replication. The duplicated DNA is then segregated into two "daughter" cells that inherit the same genetic information. This process is called chromosome segregation.

2: Cellular differentiation is the process in which a cell changes from one cell type to another. Usually, the cell changes to a more specialized type. Differentiation occurs numerous times during the development of a multicellular organism as it changes from a simple zygote to a complex system of tissues and cell types.

3: Stem cells have unique abilities to self-renew and to recreate functional tissues. Stem cells have the ability to self-renew. Unlike muscle cells, blood cells, or nerve cells—which do not normally replicate— stem cells may replicate many times.

Explanation:

Goooooooooooooooooogle <3

state birth control methods according to Islam view?​

Answers

oral contraceptives, condoms, coitus interruptus, injections, spermicides, subdermal implants

Answer:

Writings of Muslim jurists make it clear that Islam allows for the use of reversible methods of contraception (birth control), including oral contraceptives (birth control), condoms, coitus interruptus, emergency contraception, injections, subdermal implants, IUDs, spermicides, and diaphragms.

Explanation:

syngamy and triple fusion difference​

mark me as brainlest

Answers

Answer:

Üçlü füzyonda, üçüncü bir sperm çekirdeği, embriyo kesesindeki merkezi hücre ile birleşerek endospermi üretir. Eşleşme ve üçlü füzyon arasındaki temel fark, eşleşmenin bir tür üretici döllenme olduğu, üçlü birleşme ise bir tür bitkisel döllenmedir .İyi Çalışmalar..

Answer:

Syngamy: Syngamy refers to the fusion of gametes in fertilization.

Triple Fusion: Triple fusion refers to the fusion of a sperm cell with the two polar nuclei during the double fertilization in angiosperms.

Type of Fusion

Syngamy: In syngamy, a male gamete fuses with a female gamete.

Triple Fusion: In triple fusion, a male gamete fuses with the central cell.

Result

Syngamy: Syngamy produces the zygote that develops into the embryo.

Triple fusion: Triple fusion produces the endosperm cell that develops into the endosperm.

Ploidy

PloidySyngamy: The result of the syngamy is diploid.

Triple Fusion: The result of the triple fusion is triploid.

Type of Gametes

Type of GametesSyngamy: Both male and female gametes are involved in the syngamy.

Triple Fusion: Only male gametes are involved in the triple fusion.

Type of Fertilization

Syngamy: Syngamy is a generative fertilization.

Triple Fusion: Triple fusion is a vegetative fertilization.

Occurrence

OccurrenceSyngamy: Syngamy occurs in animals and plants.

Triple Fusion: Triple fusion occurs in angiosperms.

Conclusion

Syngamy and triple fusion are two types of events in the sexual reproduction of plants. Syngamy is the fusion of male and female gamete, producing the zygote. Triple fusion is the fusion of a male gamete with the central cell of the female gametophyte, producing the endosperm. The main difference between syngamy and triple fusion is the type of fusion of cells in each event.

I hope it's helpful!

Government agencies regulate most aspects of agricultural safety.
True
False

Answers

Answer:

False

Explanation:

What happens to the effenciency of the exchange of oxygen in the human body at a high altitude​

Answers

Answer:

The effiency decreases at higher altitudes

Explanation:

The higher up a person is on a mountain, the thinner the air is due to the lack of plants that can grow. An example of this is Mount Everest. At a certian point on the mountain, called the "Death Zone", the air is too thin to supply enough oxygen to the human body to survive. That's why they bring oxygen tanks with them on their adventures.

What change caused the population increases around point A?

Answers

At point A, the birth rate is much higher than the death rate hence there is an increase in the population.

What is the population?

The term population has to do with the number of organisms that live in a particular habitat at a particular time. There are two main forces that control the population of a place and this is the birth rate and the death rate.

The birth rate refers to the number of the new individual organisms that are added to the habitat while the death rate refers to the number of organisms that leave the habitat. This could be used to decipher the trend in the population as discussed below.

Given that a population in which the birth rate is far higher than the death rate would experience an explosion, such a population would now grow in leaps and bounds and it would be difficult to contain the number of individuals therein.

Learn more about population:https://brainly.com/question/27991860

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Describe how proteins form (polypeptide)

Answers

Answer: Atoms were created after the Big Bang 13.7 billion years ago. As the hot, dense new universe cooled, conditions became suitable for quarks and electrons to form. Quarks came together to form protons and neutrons, and these particles combined into nuclei.

Answer:

Within a protein, multiple amino acids are linked together by peptide bonds, thereby forming a long chain. Peptide bonds are formed by a biochemical reaction that extracts a water molecule as it joins the amino group of one amino acid to the carboxyl group of a neighboring amino acid.

The picture shows an organ system in the human body
Brain
Nerve
-Spinal
cord
w
do these organs do in the human body?
O A. They filter pathogens and dead cells out of lymph before it returns
to the blood.
B. They monitor and react to changes in the body and its
environment
C. They release hormones that control the activities of cells and
organs
O D. They identify and destroy things that are foreign or harmful to the
body

Answers

Answer:

B

Explanation:

because the nerval system is for sending and capturing signals from the brain to monitor if you had a broken bone so your brain and nerves say you are feeling pain. on rare occasions the nerves will totally skip the pain part and send different information to your brain, like if you broke your finger, it would skip the pain and all you would see is a weird finger.

Yes it’s b Nice one

Germs that cause diseases?

Answers

Answer:

There are two main types of germs which can cause disease in humans and animals. These are bacteria and viruses. Bacteria are larger than viruses.

Explanation:

A football is kicked by a player. The ball travels 50 m, to the west when it is caught by another player and that player travels 50 m, south. Create a vector diagram that shows both displacement vectors and the resultant displacement vector of the football.Use the scale of 1 cm of the graph paper = 10 m of motion.

Answers

Answer:

The football will hit the ground 2.11 seconds later.

Explanation:y = y0 + v0yt + ½ayt

2

0 = v0sin  t + ½ayt

2

0 = t(v0sin + ½ayt)

t = 0 or v0sin + ½ayt = 0

½ayt = – v0sin

=

−20sin

=

−2(18.0)sin(35.0°)

−9.8

PLEASE HELP IM DOING A TEST RN!!
Which of the following describes how the pollen must travel in order for pollination to occur?

Question 18 options:

. from the stigma to the anther


from an anther to the style


from an anther to the stigma


from the stigma to the pollen tube

Answers

Answer:

from an anther to the stigma

Explanation:

Answer:

Anther to stigma!

The anther is where the pollen is granulated, and the stigma is the part where they reproduce.

Which is the primary source of stem thickening in plants? xylem vascular cambium internal phloem

Answers

The primary source of stem thickening in plants is the vascular cambium. It is a plant tissue located between the phloem and the xylem and in the root of a vascular plant. It is the source of secondary growth or the radial growth of the stem of a plant.

Anyone know this question?​

Answers

won’t let me do it hold on

Answer:

Its below in the explanation

Explanation:

the

AA is Hh

Bb is Hh

Cc-Hh

Dd-Hh

Ee-Hh

ff-HH

GG-HH  

HH-HH

ii-Hh

Jj-Hh

kk-HH

Ll-Hh

Mm-Hh

nn-HH

oo-HH

Pp- Hh

Mitosis a single cell divides to produce two daughter cells what must happen in the original sound of the daughter cells has a complete set of chromosomes

Answers

Answer:

Explanation:

In mitosis, when a single cell divide into two daughter cell and each daughter cells have a copy of chromosomes, there must first be the copying of the chromosomes from the parent cell and after that the chromosomes are separated or there is separation of chromosomes into each of the daughter cells.

Based on your knowledge of the relationship between CO2 and photosynthesis explain why CO2 cycles throughout the year.

Answers

Answer:

we breath in Oxygen and breath out CO2 and CO2 destroys the atmosphere

A student flips a light switch but the light does not turn on. Based on this
information, which inference is NOT valid? *

The light switch is broken

The elecrical wire is copper

The electrical connection is broken

The light bulb is burned out

Answers

Electrical wire is copper

Answer: the electrical wire is copper

Explanation:

Explain why society has been developing different renewable resources in favor of
nonrenewable resources in the past few decades.

Answers

Answer: Society has been developing different renewable resources in favor of nonrenewable sources in the past decades because natural gas and oil has been used to much that we are running out of nonrenewable sources. So society has been trying to use solar panels, wind panels, and water.  

Explanation:

which part of the eye is sensitive to light?

Answers

Which part of the eye is sensitive to light?

Retina

sorry kalo salah

To ligth The sensitive of teh eye


What would happen if there was too much Carbon Dioxide in the atmosphere? What if there were no processes to pull Carbon
Dioxide out of the atmosphere?

Answers

We would die because if humans take in to much Carbon Dioxide but no oxygen it would become harder to breathe CD poisoning can effect the central nervous system. The earth would turn very hot and increase the process of global warming

what is the nature of cell-walls in diatoms​

Answers

Answer:

The cell walls of diatoms are made of silica. Their cell wall construction is known as frustule. It consists of two thin overlapping shells that fit into each other such as a soap box. When the diatoms die, the silica in their cell walls gets deposited in the form of diatomaceous earth.

Which of the following are prokaryotic cells?

A) plants

B) fungi

C) bacteria

D) animals

E) B and C only

Answers

fungi, bacteria

If I remember right, eukaryotic means there's more than one, so I believe this answer is right

The Answer is c: bacteria

The genetic makeup of an organism or its combination of alleles

Answers

Answer:

Genotype

Explanation:

SOMEONE PLEASE HELP ME WITH THIS I REALLY NEED HELP I WILL GIVE BRAINLY IF U GET IT RIGHT

Answers

im pretty sure it’s c

I would say C is the answer

Which is the last link in the wetlands food chain?
A. Consumers
B. Predators
C. Decomposers
D. Producers

Answers

It should be C. decomposers

Answer:

BRO THE CORRECT ANSWER IS .... C) DECOMPOSTER

Explanation:

I KNOW IT IS SAME BUT STILL YOU CAN MARK ME AS BRAINIEST

Can someone help me fill in the blanks. Thank you.​

Answers

Answer:

1) fungi

2) tubers

3)bulbs

4) unequally

5) cuttings

6)equally

7)root

8) mitosis

this my knowledge on this questions...hope i helped!

A cell containing 20 chromosomes undergoes mitosis, each daughter cell will have 20 chromosomes
a.True
b.False

Answers

Answer:

the answer is true because a cell containing 20 chromosomes undergoes mitosis, each daughter cell will have 20 chromosomes

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