What are the advantages and disadvantages of the serial dilution-agar plate procedure?
Answer:
Advantages
- Serial dilution is used in microbiology to estimate the concentration or number of cells/organisms in a sample to obtain an incubated plate with an easily countable number of colonies.
- In biochemistry, serial dilution is used to obtain the desired concentration of reagents and chemicals from a higher concentration.
- In pharmaceutical laboratories, serial dilution is performed to receive the necessary concentration of chemicals and compounds as this method is more effective than individual dilutions.
- In homeopathy, homeopathic dilutions are used where a substance is diluted in distilled water or alcohol. It is believed than dilution increases the potency of the diluted substance by activating its vital energy.
Disadvantages
- An error might occur during the propagation of the sample, and the transfer inaccuracies lead to less accurate and less precise transfer. This results in the highest dilution to have the most inaccuracies and the least accuracy.
- Because serial dilution is performed in a stepwise manner, it requires a more extended period of time which limits the efficiency of the method.
- Serial dilution only allows the reduction of bacteria/cells but not the separation of bacteria/cells like in other techniques like flow cytometry.
- This technique also requires highly trained microbiologists and experts in aseptic techniques.
What do you observe about the structure
of the white blood cell? How do you think
this is related to its function of trapping
pathogens in the body?
Please help I’ll give brainlyiest
Answer:
White blood cells engulf and digest pathogens and any other unknown material in the blood and tissues. They engulf the pathogen into a vesicle called a phagosome. This fuses with a lysosome and the enzymes break down the pathogen.
White blood cells foremostly recognize any pathogen or foreign substance in the body and then engulf it with the help of receptors like Toll-like receptors. Finally, the killing of antigen takes place by phagocytosis.
What do you mean by Pathogens?Pathogens may be defined as any microorganisms which are capable of inducing diseases in other living organisms.
After engulfing, the antigen is packed under a vesicle known as a phagosome. This phagosome is then treated with lysosomes to form a structure known as phagolysosomes.
Thes phagolysosomes are responsible for the breakdown of antigen, which is then presented by MHC molecules to perform perforin-granzyme mediated killing of antigen.
Therefore, it is well described above.
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9.
Strand A would normally be found in the
A. plasma membrane
B. ribosome.
Yasuole
nucleus
Answer:
the Nucleus
Explanation:
Which of the following is most likely true of a protein that cotransports glucose and sodium ions into the intestinal cells of an animal?
A) Sodium and glucose bind to the same site on the cotransporter.
B) Transport of glucose against its concentration gradient provides energy for uptake of sodium ions against the electrochemical gradient.
C) Sodium ions can be transported whether or not glucose is present outside the cell, but glucose transport requires cotransport of sodium ions.
D) Transport of sodium ions down their electrochemical gradient facilitates the transport of glucose against its concentration gradient.
E) Following transport of sodium ions into the cell, the cotransporter can also transport potassium ions out of the cell.
Answer:
D) Transport of sodium ions down their electrochemical gradient facilitates the transport of glucose against its concentration gradient.
Explanation:
Active transport refers to the movement of molecules across biological membranes against a concentration gradient. Active transport can be divided into 1-primary active transport, which requires energy from the hydrolysis of adenosine triphosphate (ATP); and 2-secondary active transport, which requires an electrochemical gradient generated by pumping ions in/out of the cell. The case above described represent a type of secondary transport active because the movement of sodium (Na) ions is used as energy source to move glucose molecules against their concentration gradient.
Answer: Transport of sodium ions down their electrochemical gradients facilitates the transport of glucose against its concentration gradient.
Which two events take place during human sexual reproduction?
A. Fragmentation
B. Spore formation
C. Fertilization
D. Gamete formation
Answer and Explanation:
C...
Gamete formation and fertilization takes place during human reproduction. Therefore, option (C) and (D) are correct.
What is sexual reproduction in humans?Human fertilisation produces a human child via human reproduction, which is reproduction. It usually entails activity between a sexually mature male and female person.
Copulation, or sexual intercourse, involves the insertion of the erect into the vagina and the ejection of spermatozoa from the seminal fluid (semen) into the female genital tract. The ovum in the outer portion of the fallopian tube is subsequently fertilised by spermatozoa as they travel from the vagina via the uterus to the tube.
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A microscope has a 4x ocular lens and a 10x objective, what is this microscope's
total magnification?
4x
14x
40x
400x
Answer:
It would be 40x
Explanation: The explanation is that 10x and 4x is 40x on a microscope unless you are working with a different type of microscope with the 50x ocular lens
What is active transport?
Answer:
the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy.
Explanation:
Why are fossil fuels considered nonrenewable resources? A. They form quickly due to decaying biomass. B. They require both sunlight and water to form. C. They cannot be used to create electricity. D. They take millions of years to form.
Answer:
B
Explanation:
Just go with it.
It's Right.
Describe how the movement of water landforms form
Answer:
The moving of water causes erosion, deposition and much more!
Explanation:
Water moving across the earth in streams and rivers pushes along soil and breaks down pieces of rock in a process called erosion. The moving water carries away rock and soil from some areas and deposits them in other areas, creating new landforms or changing the course of a stream or river.
Sense helps in translating outside information in understanding
the environment.
Select one
True
False
Answer:
true
because of sense we only understand our environment
if there will no sense
then there will no mean of anything
The phase of mitosis that is characterized by the arrangement of all chromatids along the equator of the cell is called
Helppppppppppppppppp
In normal cells the amino acid phenylalanine attaches to tRNAs with the anticodon AAA. The enzyme aminoacyl-tRNA synthetase catalyzes the reaction that attaches the amino acid to the correct tRNA. Assume that a mutation occurs in the aminoacyl-tRNA synthetase enzyme and causes it to attach lysine instead of phenylalanine to tRNAs with the anticodon AAA. What will be the consequence of this mutation for the translation process
Answer:
Aminoacyl-tRNA bond is hydrolyzed.
Explanation:
The consequence of this mutation for the translation process is the hydrolysis of aminoacyl tRNA bond occur. If the incorrect amino acid is attached to other molecule as a result of this reaction, the aminoacyl-tRNA bond is hydrolyzed. This incorrect binding of amino acid occur because of mutation in the aminoacyl-tRNA synthetase enzyme that leads to its hydrolysis.
PLSSS HELPPPPPP
5. How does low biodiversity impact the stability of a tundra ecosystem?
4. Who else benefits from polar bear hunting?
3. Describe a polar bears niche.
1. How do tundra ecosystems in biodiversity compare in biodiversity to other types of ecosystems?
Answer: 5. Biologically numerous groups also are much more likely to include species that confer resilience to that ecosystem due to the fact as a network accumulates species, there may be a better risk of anybody of them having developments that permit them to conform to a converting environment.
3. The polar bear's ecological niche is that of a specialized predator of seals. When there are numerous seals around, adult polar bears will usually devour the blubber (fat) and pores and skin of the seals, which gives an awesome supply of energy. Younger bears will devour beef because the protein allows them to grow.
Explanatation:
Got them from g o o g l e but kind of change it up a bit
1. How do tundra ecosystems in biodiversity compare in biodiversity to other types of ecosystems?
Answer: Ecosystems in the arctic tundra are an example of those where there are fewer species overall than in other kinds of ecosystems.
2. What is a niche?
Answer: a role that a species plays in the ecosystem
3. Describe a polar bear's niche.
Answer: Some animals gain from polar bears' hunting of seals. A polar bear will leave behind significant portions of a seal after eating all of it. In tundra environments, these leftovers are a source of food for Arctic foxes, gulls, and other birds, particularly during the chilly winter months when there is nothing to eat. Healthy polar bear populations can have a good effect on other species' numbers, such as those of birds or Arctic foxes. Numerous other species are harmed when polar bear populations drop.
4. Who else benefits from polar bear hunting?
Answer: Arctic foxes, gulls, and other birds
5. How does low biodiversity impact the stability of a tundra ecosystem?
Answer: The species that provide resilience to an ecosystem are therefore far more likely to be found in biologically diverse groups because as a network accumulates species, there may be a greater chance that any one of them will have evolved to adapt to a changing environment.
A ______ is a type of turbine used to capture the energy of moving air. A. geotherm B. windmill C. solar panel D. dam
Answer:
b windmill
Explanation:
A windmill is a type of turbine used to capture the energy of moving air.
Windmills have been used for centuries to power grain mills, water pumps, and other mechanical devices. In modern times, wind turbines are often used to generate electricity on a large scale.
Wind turbines typically consist of a rotor with two or three blades that spin around a horizontal or vertical axis. As the wind blows, it pushes the blades, causing them to rotate and give energy. The rotating blades turn a shaft, which is connected to a generator that produces electricity.
Wind turbines can range in size from small turbines used to power individual homes or businesses to large utility-scale turbines used to generate energy for the grid.
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40 BRAINLEY
FFFFFFFFFFFFFFFFFFF
Which cell structure serves the stated function in both eukaryotic and prokaryotic cells?
nucleus: stores genetic material
O cytoplasm: protects cell structures
O ribosomes: regulate cell processes
O DNA: surrounds cell contents
Answer: O cytoplasm: protects cell structures
Explanation:
sam enjoys looking at the stars through his telescope he learns that start were originally clouds made of dust and gasses which statement best describes how these clouse eventually become stars
A. The clouds eventually collapse the force of gravity
B. The clouds increase in temperature until they eventually form a solid
C. The clouds contain particles that are magnetically attracted to each other
D. The clouds begin to cool and fort from masses of ice that eventually fuse together
Answer: A
Explanation:
The statement which best describes how the clouds eventually become stars is that— “The clouds eventually collapse under the force of gravity”. Hence, the correct option is A.
What are stars?Star are huge celestial bodies that are formed by the vast clouds that exist in interstellar space. These clouds are mainly composed of hydrogen and helium gas as well as small amounts of heavier elements such as carbon, nitrogen, and oxygen.
Overtime, the clouds begin to collapse under their own gravity and as they do, they become denser and more compact. As the cloud collapses, it begins to spin and then flattens into a disc-like shape. This disc becomes the birthplace of new stars.
The process of star formation is not simple and straight forward. Hence, the first step of formation of stars is the cloud collapses under its own force of gravity. Therefore, option A correct.
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(iv) Measles. Mumps, Diphtheria Polio odd one
Answer: The odd one one is diphtheria
Explanation:
There are very minute living organisms that are able to cause different diseases to human which are found in our environment. These are known are microorganisms. They include:
--> viruses
--> bacteria
--> fungi
These microorganisms are able to establish an INFECTION in its human host when it's able fight and overcome the body defence mechanism of the host.
Diphtheria is the odd one because it's an infection which is caused by BACTERIA organism while other options while includes measles, mumps and polio are caused by VIRUS microorganisms.
BACTERIA are the larger microorganisms with a very simple cell structure where the nucleus is not enclosed within a membrane. While VIRUS are the simplest and smallest microorganisms which do not have a cell structure.
Diphtheria is an infection caused by the bacteria microorganism known as the Corynebacterium diphtheriae. These bacteria are able to produce toxins which is its virulent factor that are poisonous to its host.
Measles is an infection caused by paramyxovirus.
Mumps is an infection caused by mumps virus
Polio is an infection caused by picornavirus.
Therefore, Diphtheria infection is the odd one out.
Which skull bone is part of the facial bones and contains teeth?
Answer:
The anterior skull consists of the facial bones and provides the bony support for the eyes and structures of the face. This view of the skull is dominated by the openings of the orbits and the nasal cavity. Also seen are the upper and lower jaws, with their respective teeth
3. Calculate the kinetic energy of a paper clip shot from a slingshot. The paper clip's mass is 0.01 kg, and its velocity is 10 m/s.
a) 0.1 J
b) 0.25 J
c) 0.5 J
d) 1 J
Answer:
C
Explanation:
0.01kg*(10m/s)^2/2=0.5
If Ava drops a 5 kg ball off a 20 meter building and Clayton drops a 5 kg ball
off a 40 meter building, which ball will have more potential energy?"
A.Ava's ball
B.Clayton's ball
what does it mean to say that CO2 becomes "fixed" during photosynthesis
Answer:
What does it mean to say that CO2 becomes "fixed" in talking about photosynthesis?
A. CO2 becomes bonded to an organic compound.
Explanation:
Muscle tissues are made of specialized unitss called?
Answer:
Each skeletal muscle fiber consists of a bundle of myofibrils, which are bundles of protein filaments. The filaments are arranged in repeating units called sarcomeres, which are the basic functional units of skeletal muscles.
Explanation:
Answer:
skeletal muscle
Explanation:
I need help with question 54 .
Answer: D
In the laboratory, under favorable conditions, a bacterial population will grow exponentially, but in the real environment, these favorable conditions do not always exist.
Cell X
Cell w
Cell Y
Cell Z
Х
х
х
Cell Membrane
x x
х
х
Cell Wall
Chloroplasts
Х
х
DNA
х
х
х
Nucleus
Х
Х
х
Which cell that was viewed is most likely a prokaryote?
nucleus,cell membrane
The diagram below shows a ciliated cell from the lining of the airway.
Which of the following states its function?Required to answer. Single choice.
(1 Point)
A)it is the place where diffusion of gases take place
B)it moves mucus and sweeps dust from lungs
C)it secretes trypsin
Pls tell meeee quickkk
Answer:
the answer is a. any ciliated cell in lungs catches bacteria & debris from lungs causing cough, difficulty breathing, etc.
can develop into asthma, infection of pleura, and bronchitis...
Pyruvic acid passes through two
of the
and into the
Explanation:
I don't know
in drosophila melanogaster, the common fruit fly, curved wings "I" and purple eyes "r" are two linked recessive genes found on chromosomes 2. The dominant wild type alleles for those genes are long wings"L" and red eyes "R"
a)describe the expected ratio of offspring in the f2 generation of these genes were located on different chromosomes
b)the results in the f2 generation of these flies were: 40 long winged, red eyes; 40 curved winged, red eyes; 10 long winged, purple eyes, and 10 curved winged, red eyed. how many map units apart are the genes for curved wings and purple eye color?
Answer:
the other person is right, he had messed up before saying that 60 x 40 = 100, but 60 + 40 = 100. Then I had told him that his answer was wrong and that he should put the answer as 240 instead since 60 x 40 = 240 and not 100.
Explanation:
The expected ratio of offspring in the f2 generation of these genes were located on different chromosomes is 25%
What are chromosomes?A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are the histones.
Chromosomes allow DNA to be accurately copied during these cell divisions. So one more time. Chromosomes are found in the nuclei of our cells and allow DNA to be accurately copied during cell division.
Chromosomes are thread-like structures located inside the nucleus of animal and plant cells. Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA).
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-2 In a pasture ecosystem a large portion of the biomass is represented
pasture vegetation compared to animals that feed on these grasses.
illustrated by such a pasture ecosystem is called alan...
A food chain.
B food web.
с ecological pyramid.
D energy flow.
a
Explanation:
im not really sure about the answer i chosed but maybe yes