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?
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
Considering your knowledge of carbohydrates, evaluate the use of chitin as a component of health foods.
Answer:
Carbohydrates may be defined as energy-rich foods such as sugars and starches. if consumed in excess or not properly metabolized in the body, carbohydrates may lead to obesity and which may also lead a person to severe number of diseases.
Chitins are components of the exoskeletons of foods such as shrimps, crabs and snails, and insects.
Chitin's use as a component in healthy foods is based on its health benefits.
For example it promotes weight loss , prevents obesity, relieving constipation and preventing inflammation associated with refined carbohydrates, cookies and candies
what are the components of blood
1 . RBC red blood cells
2. WBC white blood cells.
Answer:
plasma, RBCs, WBCs, platelets.
Which of the following is the best definition of climate?
1 . The day to day changes in the atmosphere
2. The average weather over a long period of time and over large areas
3. The state of the atmosphere across the world
Answer:
THE STATE OF THE ATMOSPHERE ACROSS THE WORLD IS THE BEST FROM MY OPINION .
Answer : 1
Explain: The day to day changes in the atmosphere
Which statement describes her hypothesis
Answer:
A hypothesis is a plausible answer to a scientific problem or question that is testable, but not yet tested. Some science textbooks call it an "educated guess.
A couple owned a fine pure-bread albino female poodle (an autosomal recessive phenotype) and wanted to mate her to produce a litter of white puppies. They took her to a breeder, who said he would mate the female with an albino stud male, also from a pure stock. When six puppies were born, they were all black, so the couple sued the breeder, claiming that he had replaced the stud male with a black dog, producing six unwanted puppies. You are called as an expert witness, and the defense asks you whether it is possible to produce black offspring from two pure-breeding recessive albino parents. What testimony do you give
Answer:
No, it is not possible to produce black offspring from two pure-breeding recessive albino parents. If he would have mated the female with a white male, the whole progeny should be white.
Explanation:
Due to technical problems, you will find the complete explanation in the attached files.
What causes fingers to look wrinkled after soaking in water?
O A. The skin cells lose all their water.
O B. Water enters the cells in the skin.
O C. The skin cells shrink in size.
.
D. Salt enters the skin cells.
Answer:
B. Water enters the cells in the skin.
Explanation:
ASAP
The genetic code contains thousands of genes. Each gene codes for a
specific
A. fatty acid
B. amino acid
C. polypeptide
D. polysaccharide
Answer:
amino acid
Explanation:
The genetic code contains thousands of genes. Each genetic code represents a specific amino acid. Hence, option B is correct.
What is Genetic code?A genetic code represents a set of three-letter that are a combination of nucleotides known as codons. Each of them correlates to a particular amino acid.
Amino acids are the molecules that combine to form protein which serves as the base of life. Genetic code is translated into a sequence of amino acids with the help of a codon table.
Codon is a sequence of three nucleotides that form a unit of genetic code in DNA or RNA molecules.
Therefore, the amino acid is represented by each genetic code. Thus, option B is correct.
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Which statement is most likkely to applyto a cell that has DNA whitin its ytoplasm
Answer:
It performs all functions for the organisms
what is uropoiesis?
Answer:
The production and excrection of urine
Answer:
The production and excretion or urine.
1. Describe the purpose of mitosis.
2. Describe what is happening in each stage and what each stage looks like:
Prophase
Prometaphase
Metaphase
Anaphase
Telophase
Cytokinesis
Answer:
1) The purpose of mitosis is growth and repair of cells
Explanation:
Prophase:
-DNA condenses (supercoiled, chromatids are visible under light microscope);
-Nuclear membrane begins to disintegrate (by the end of prophase it is completely gone)
-Centrioles move to opposite ends of the cell
-Splinde fibers start to form from the centrioles and grow
Metaphase:
-Spindle fibers, departing from both poles, are attached to each centromere, on opposite sides
-The spindle fibers pull the chromosomes back and forth until they align in a plane along the equator of the cell, which is called the equatorial plane
Anaphase:
-The spindle fibers shorten
-The centromeres of sister chromatids split
-Chromatids move apart, pulled by the spindle fibers
-Chromatids become chromosomes
-Half of the chromosomes move to one cell pole, half to the other
Telophase:
-The chromosomes reach the cell pole
-Nuclear membrane reforms
-Spindle fibers break down and disappear
-The chromosomes begin to uncoil, which makes them diffuse and less compact
Cytokinesis:
-The cell membrane pinches inward until the cell divides in two;
-There are two daughter cells with the same structures and number of chromosomes as the parent cell
-Chromosomes decondense
Issued in 1974, 45 CFR 46 raised to regulatory status:
A) The 1974 National Research Act
B) The Nuremberg Code
C) Kefauver-Harris Drug Amendments to the Federal Food, Drug & Cosmetics Act
D) US Public Health Service Policy
Hello!
The answer is D, The U.S Public Health Service Policy. Its main purpose was providing protection for human subjects for research work which was conducted by federal agencies. You can read more about it on HHS.gov, as it is a very interesting regulation.
I hope this helps! :)
Issued in 1974, 45 CFR 46 raised to regulatory status US Public Health Service Policy. Option D
What is the regulatory status?The restrictions known as the Common Rule for the protection of human subjects in research done by or supported by federal agencies are outlined in Title 45 of the Code of Federal restrictions, Part 46. These laws define moral principles and requirements for the protection of research subjects who are being used as human subjects.
The US Public Health Service (PHS) published the policy that would eventually become 45 CFR 46 in 1974. This policy established standards for the examination and approval of research involving human subjects as well as the legal foundation for the protection of those individuals. Informed consent, weighing risks and benefits, and the creation of Institutional Review Boards (IRBs) to regulate research techniques were all adopted.
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Al wonders if adding salt to water will affect how long it takes the water to freeze. Al thinks that salt water will freeze more quickly than fresh water. He decides to check his hypothesis by conducting an experiment. Al takes two ice trays and fills one with distilled water and the other with distilled water that has two tablespoons of salt added. He makes sure he puts exactly the same amount of water in each ice tray. Al takes the trays and puts them side by side in the freezer. Al checks the ice trays every 10 minutes to see if the water in each tray has begun to freeze. Al finds that after 20 minutes the water in the ice tray without the salt has started to form ice, while the ice tray with the salt water is still completely liquid.
What is his hypothesis?
a. Salt water freezes slower than fresh water.
b. Water freezes in a freezer
c. Salt water freezes faster than fresh water.
d. water will freeze in 20 minutes
salt water freezes slower than fresh water
Which of the following processes releases heat?
Evaporation
Freezing
Melting
Sublimation
Answer:
Freezing
Explanation:
I got 123% on the quiz (Jokes aside yes it is freezing)
When does facilitated diffusion occur?
-When one liquid has a higher osmotic pressure than the other.
-When certain large molecules are unable to move through the membrane
without the help of channel proteins.
-When ATP is available to assist in moving molecules.
-When there's a strong membrane potential present, with the inside of the cell
being more negative than the outside of the cell.
Answer:
When certain large molecules are unable to move through the membrane without the help of channel proteins
Explanation:
Facilitated diffusion occurs when large molecules that are unable to pass through a membrane on their own make use of channel proteins to move from one side of the membrane to the other. Facilitated diffusion can occur when a liquid on one side of a membrane has a higher osmotic pressure than a liquid on the other side of the membrane, but it isn’t a required feature of facilitated diffusion. Similarly, facilitated diffusion can occur when there’s a large membrane potential present, but it isn’t a required feature of facilitated diffusion. Facilitated diffusion doesn’t require the use of energy, so the presence of ATP is irrelevant to facilitated diffusion occurring.
A cytoskeleton is:_______.
a. a structure that aids in the process of cell division.
b. found in the cytoplasm of eukaryotic cells.
c. a system of tracks used for transport.
d. composed of microtubules and microfilaments.
e. All answers are correct.
Answer: e
Explanation: Cytoskeleton is a microfilaments, intermediate filaments, and microtubules that provide support and movement for eukaryotic cytoplasm.
1. Prokaryotic cytoplasm lacks certain features of eukaryotic cytoplasm, such as cytoskeleton and cytoplasmic streaming.
2. The cytoskeleton provides support and shape to cell.
3. It help in transporting substances through cell.
4. It help in phagocytosis.
5. It help in cytoplasmic streaming that is movement of eukaryotic cytoplasm from one part of cell to another which help distribute nutrients and move the cell over the surface.
6. The study of the numerous interaction between microbes and host cell cytoskeleton is a very intense area of investigation on virulence mechanism.
All answers are correct. Therefore, option (E) is correct.
What is cytoskeleton?The cytoskeleton is a complex network of protein filaments that extends throughout the cytoplasm of eukaryotic cells. It plays a number of important roles in the cell, including providing structural support, helping cells maintain their shape, and assisting in the movement of organelles and other cellular components. The cytoskeleton is also involved in the process of cell division, or mitosis, which is the process by which a single cell divides into two daughter cells.
The cytoskeleton is composed of three types of protein filaments: microtubules, microfilaments, and intermediate filaments. Microtubules are long, thin protein fibers that form a kind of scaffolding within the cell. Microfilaments, which are made of actin proteins, are thinner than microtubules and are involved in muscle contraction and cell movement. Intermediate filaments are thicker than microfilaments and provide structural support to the cell. Together, these three types of protein filaments form a system of tracks that can be used for transport within the cell.
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¿Porque las vitaminas, las sales minarales y el agua se consideran reguladores?
Answer:
Vitamins and minerals boost the immune system, support normal growth and development, and help cells and organs do their jobs. For example, you've probably heard that carrots are good for your eyes. It's true! Carrots are full of substances called carotenoids (pronounced: kuh-RAH-teh-noydz) that your body converts into vitamin A, which helps prevent eye problems.
Vitamin K helps blood to clot, so cuts and scrapes stop bleeding quickly. You'll find vitamin K in green leafy vegetables, broccoli, and soybeans. And to have strong bones, you need to eat foods such as milk, yogurt, and green leafy vegetables, which are rich in the mineral calcium.
Classify amoeba to species level
what is the function of folds and villi
Answer:
The inner wall of the small intestine is covered by numerous folds of mucous membrane called plicae circulares. The surface of these folds contains tiny projections called villi and microvilli, which further increase the total area for absorption.
Explanation:
Hope this helps
A ______, such as a bean, has two seed leaves.
Answer:
A dicotyledonous plant
hope this helps you
From a population of red, brown, orange, yellow, and green butterflies, only the red and green ones survive since they can blend into their environment and reduce predation. Which evolutionary mechanism is involved?
Answer:
Natural Selection
Explanation:
Since the other species don't survive naturally, the red and green ones continue to breed so that their species will continue to live.
You are in charge of genetically engineering a new organism that will derive all of its ATP from sunlight by photosynthesis. Will you put the enzymes of the citric acid cycle in this organism
Answer:
Yes.
Explanation:
I will put the enzymes of the citric acid cycle in this organism so that in the absence of sunlight, it also produces energy to grow quickly. Citric acid cycle is a series of chemical reactions which release stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins. This cycle is also called Krebs cycle so incorporation of this cycle is good for the organism.
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:
Please use the following information to answer the questions below. The southern grasshopper mouse feeds regularly on the Arizona bark scorpion, the most venomous scorpion in the United States. While attempting to capture the scorpion, the mouse usually gets stung multiple times by the scorpion but does not seem to be affected. While attempting to capture the scorpion, the mouse's heart rate increases, and there is an increase in epinephrine in the mouse's blood. What nervous system division is responsible for the mouse's physiological state
The sympathetic nervous system is responsible for the mouse's physiological state.
The nervous system divides into the central nervous system and peripheral nervous system.
In the central nervous system, we have the brain and the spinal cord.
The peripherical nervous system, which is all the nerves that are not in the spinal cord or the brain, is divided into:
The somatic nervous system, which is the one that makes the conscious movements of our body.The autonomic nervous system consists of:-Sympathetic nervous system. It is the one that works under stress. It gives the fight or flight response preparing the body for a dangerous situation. It increases the heart rate and epinephrine's release. Epinephrine is a hormone that helps in this response stimulating the sympathetic system.
-Parasympathetic nervous system. It is the one that works in calm situations, like after we ate, regulating digestion, and trying to save energy for any upcoming event.
In conclusion, as there is an increase in epinephrine and heart rate, and the mouse is "fighting" against a scorpion, the nervous system division responsible for this physiological state is the sympathetic nervous system.
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HELP!!!
1. In a parent pea plant with the allele pair Gg, what is the probability that one gamete will contain the G allele? Why?
2. In a parent pea plant with the allele pair GG, what is the probability that one gamete will contain the g allele? Why?
3. In a parent pea plant with the allele pair gg, what is the probability that one gamete will contain the g allele? Why?
Answer:
If the gamete will get either G or g, the probability will be 1/2 of getting G.
Explanation:
all question 3 answer is that. Because all 3 of question are same. only repeated three times
In a parent pea plant with the allele pair Gg, the probability that one gamete will contain the G allele is 0.5. This is because there are two possible outcomes in which one must definitely fall. So, it is 1/2.
What is Allele?Alleles may be characterized as the alternative form or versions of a gene that are responsible for particular traits in living organisms. They carry a code of genetic sequences within generations.
In a parent pea plant with the allele pair GG, the probability that the gamete will contain the g allele is zero. This is because there is no presence of allele g that can be determined within any gametes. So, it is not possible to get g in the pair allele of GG.
In a parent pea plant with the allele pair gg, the probability that one gamete will contain the g allele is 1 or 100%. This is because both carry g alleles. So, the probability is 100%.
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Which scientist was responsible for coining the phrase "Big Bang"? *
O Fred Hoyle
O Albert Einstein
O Sir Isaac Newton
O Edwin Hubble
Answer:
Fred Hoyle
Explanation:
Sir Fred Hoyle FRS was an English astronomer who formulated the theory of stellar nucleosynthesis. He also held controversial stances on other scientific matters—in particular his rejection of the "Big Bang" theory, a term coined by him on BBC radio, and his promotion of panspermia as the origin of life on Earth
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Answer:
Explanation:
C ạ
Most of the plant matter in ___ is sphagnum moss.
Answer:
the answer is peat
Explanation:
i did the test Hope dis help
Answer:
pease
Explanation:
I did some research
According to Sandel, when companies companies attempt to incentivize employees to quit smoking:__________
a) It never works.
b) There are no data on this incentive scheme.
c) It tends to work.
d) Employees tend to return to smoking when the incentive ends.
Answer:
employees tend to return to smoking when the incentive ends
Explanation:
because employees love to smoke on breaks and they are addicted to smoking.
Which organism exhibits behavioral adaptation?
Answer:
Humans
Birds
Bears
Chameleons
Cicadas
Explanation:
A Behavioral Adaptation is something an animal does - how it acts - usually in response to some type of external stimulus.
Examples of some Behavioral Adaptions:
Migration, Hibernation, Dormancy, Camouflage.
Answer:
Behavioral adaptations are the actions that organisms take in order to stay alive. Behavioral adaptations include things like bird cries and migration. Evolution produces adaptations. Evolution is a long-term change in a species.
OAmalOHopeO:
