Answer:
Bacteriophages (phages) are viruses that infect only bacteria and do not infect mammalian or plant cells. Phages are ubiquitous in the environment. Phages or bacteriophages were chosen as a model system for their simplicity, as they only contained protein-coated nucleic acid. Alfred D. Hershey and Martha Chase (who were part of the bacteriophage group) in 1952 studying the infection of the bacterium Escherichia coli by the T2 phage show that the information definitely resides in the DNA. They used phage with either [32P] -labeled DNA or [35S] -labeled proteins to infect the bacteria. Immediately afterwards, they centrifuged the sample so that the infected bacteria remain in the pellet and the virus capsids (proteins) remain in the supernatant. [35S] is found in the supernatant, whereas [32P] is found in bacteria. After one cycle of infection, it was observed that when phage labeled in the [35S] proteins were used, only 1% of the radioactivity was incorporated into the progeny. But when phages were [32P] labeled, more than 30% of the radioactivity was in the progeny. They showed directly that what is transmitted from one progeny to another is the DNA and not the proteins, despite having first "diluted" in a bacterium.
Explanation:
Bacteriophages are viruses that infect bacteria in a specific way. Bacteriophages, like other known viruses, are found in an intermediate zone between living organisms and inert matter. Bacteriophages bind to the host pathogenic bacterium, introduce their genetic material, replicate inside it and destroy it. Hersey, along with his assistant Martha Chase, used phages because they knew that T2 phages were made up of 50% proteins and 50% nucleic acids and that phages entered bacteria and reproduced. As the progeny carried the same infection traits, the genetic material of this had to be transmitted to the offspring, but the mechanism was unknown. These scientists carried out an experimental work with the T2 virus, a bacteriophage that infects the bacterium Escherichia coli, which it reproduces by attaching itself to the outer wall of the bacterium, injecting its DNA into it where it replicates and directs the synthesis of the phage's own proteins. Phage DNA is encapsulated within proteins and produces phages, which lyse or disrupt the cell and release phage from progeny. They infected a culture of bacteria with radioactively labeled phages: the protein coat with sulfur (35S) and its DNA with phosphorus (32P). After infection, they separated the phages from the bacteria by violent shaking using a mixer (hence the name of the experiment). By centrifugation the much smaller phages remained in the supernatant and the much larger bacteria in the pellet. 85% of the radioactivity corresponding to DNA appeared in the pellet and 82% of the protein in the supernatant. This result supported the idea that DNA was the only component of the bacteriophage that penetrated the interior of the bacteria and, having the ability to form new phages, constituted the genetic material.
The grizzly bear is a mammal, belonging to phylum Mammalia and kingdom Animalia. It belongs to the genus Ursus and the species Arctos. What is the scientific name of this organism?
Ursus Arctos.........
A ray of light is passing through a medium making an angle of 45°. If the
refractive index of the medium is 1.4, calculate the angle of refraction. [Ans: 30°)
Answer: By Snell's law, we can see that the angle of refraction is 30.34°
Explanation:
Snell's law says that:
If a ray in a medium of refractive index n₁, insides with an angle θ₁ in another medium with refractive index n₂, then the angle of refraction θ₂ is given by:
n₁*sin(θ₁) = n₂*sin(θ₂)
We know that:
The incidence angle is 45°, then: θ₁ = 45°
We can assume that the first medium is air, then n₁ = 1
The refractive index of the other medium is 1.4, then n₂ = 1.4
Replacing these in the Snell's law equation we get:
1*sin(45°) = 1.4*sin(θ₂)
Now we can solve this for the angle of refraction:
sin(45°)/1.4 = sin(θ₂)
Asin(sin(45°)/1.4 ) = Asin( sin(θ₂)) = θ₂ = 30.34°
So the angle of refraction is 30.34°
Which statement accurately describes recent population density and shifts in Southeast Asia?
Rural towns have many of the same opportunities as urban centers
Indonesia’s capital of Jakarta has become a megalopolis.
The population is rapidly declining
Overcrowding has pushed many people to migrate from urban to rural areas.
Answer:
Indonesia's capital of Jakarta has become a megalopolis.
Explanation:
I took the test
Answer:
Many city people are very poor and live in urban slums.
The greatest population densities are on the coasts, along the rivers, and in deltas.
Indonesia’s capital of Jakarta has become a megalopolis.
Explanation:
just did the quiz
The diagram shows the life cycle of a fern,
What does stage 2 show?A. A gamete-producing fern plant is flat and shaped like a heart.
B. A zygote forms when a sperm fertilizes an egg cell.
C. A mature spore-producing fern plant has fronds and produces
spores
D. A spore grows into a mature gamete-producing plant,
Answer:
the correct answer is D!
A spore grows into a mature gamete-producing plant.
Explanation:
hope this helps :)
A spore grows into a mature gamete producing plant is best describe the life cycle of fern.
What is the life cycle of fern?The life cycle of the fern has two different stages such as sporophyte and gametophyte. The sporophyte stage which releases spores whereas gametophyte stage which releases gametes. Gametophyte plants are haploid whereas sporophyte plants diploid. This type of life cycle is known as alternation of generations.
So we can conclude that a spore grows into a mature gamete producing plant is best describe the life cycle of fern.
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What does a model of the carbon cycle show?
A. The amount of Earth’s carbon is constant.
B. The amount of Earth’s carbon cannot be determined.
C. The amount of Earth’s carbon decreases.
D. The amount of Earth’s carbon increases.
I think its A
Answer:
Changes that put carbon gases into the atmosphere result in warmer temperatures on Earth. This diagram of the fast carbon cycle shows the movement of carbon between land, atmosphere, and oceans. Yellow numbers are natural fluxes, and red are human contributions in gigatons of carbon per year.
The model of the carbon cycle determines the amount of earth's carbon is constant. Thus, option A is correct.
Carbon is the element that is responsible for the major life forms on earth. The conversion of carbon in varying life forms and the reservoir is given by the carbon cycle.
What is the effect of the carbon cycle on the amount of carbon?The carbon cycle is operated for the analysis of the conversion of the carbon in different states and life forms in the earth.
The conversion results in the change in the state of the carbon and its concentration in different constituents.
The earth is the reserved closed system and is consisted of a fixed amount of elements.
Thus, the amount of carbon in the earth is constant in the model of the carbon cycle. Thus, option A is correct.
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In the Hershey Chase experiment components of bacteriophages were labeled with radioactive isotopes of sulfur and phosphorus What was
the Hershey-Chase evperiment designed to determine?
Answer:
c
Explanation:
It was designed to determine whether the genetic material of the bacteriophage (a type of virus that infects bacteria) is made of DNA or protein.
What was Hershey-Chase experiment?The Hershey-Chase experiment, also known as the "Blender Experiment," was a classic experiment in molecular biology that was conducted in 1952 by Alfred Hershey and Martha Chase. It was designed to determine whether the genetic material of the bacteriophage (a type of virus that infects bacteria) is made of DNA or protein.
In the experiment, components of the bacteriophage were labeled with radioactive isotopes of sulfur and phosphorus. The labeled phages were then used to infect bacterial cells, and the cells were subjected to various treatments to separate the viral components from the bacterial components.
The results of the experiment showed that the genetic material of the bacteriophage was made of DNA, not protein. This was determined by the fact that the labeled DNA, but not the labeled protein, was able to enter the bacterial cells and infect them. This experiment provided strong evidence for the "central dogma" of molecular biology, which states that genetic information flows from DNA to protein, but not the other way around.
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hello help please i’ll mark brainliest!!!
Answer:
the secone option
Explanation:
i just need one more brainliest thanks<3
Answer: The third one
Explanation: It is the third one because scientist have been talking about how there are billions of galaxy's in our universe.
Question 6
Thermal is to heat as _____
is to water.
A. Absorb
B. Dilute
C. Waste
D. Drain
Answer:
drain
Explanation:
thermal is to hear as drain is to water
Answer:
thermal is to heat as dilute is to water
hii pls help i’ll give brainliest if you give a correct answer
Answer:
East to West
Explanation:
Drag the tiles to the correct boxes to complete the pairs.
Match the effects with their causes.
Effect: Solar wind deflects toward the poles.
Effect: An aurora is created.
Effect: Space travel through the Van Allen
belts is dangerous.
Cause: Earth’s magnetosphere traps radioactive
solar wind particles in bands around Earth.
arrowRight
Cause: Earth is surrounded by a magnetic field.
arrowRight
Cause: Solar wind particles interact with Earth’s
upper atmosphere.
arrowRight
Answer:
Cause: Earth’s magnetosphere traps radioactive solar wind particles in bands around Earth → Space travel through the Van Allen belts is dangerous.
Cause: Earth is surrounded by a magnetic field → Effect: Solar wind deflects toward the poles.
Cause: Solar wind particles interact with Earth’s upper atmosphere → Effect: An aurora is created
Explanation:
I have been able to drag the tiles to the correct boxes to complete the pairs.
When there is a trapping of radioactive solar wind particles in bands by the earth's magnetosphere, it becomes dangerous to travel in space through the Van Allen. Cosmic rays and solar particle add up to the additional hazards that it poses. A Van Allen radiation belt is known to be a zone where energetic charged particles are found. Most of the energetic charged particles originate from the solar wind. The solar wind are captured by and held around a planet by that planet's magnetic field.
When the solar wind interacts with the earth's atmosphere, there is a collision of atoms of oxygen and nitrogen from the earth's atmosphere. The energy that is formed is a colorful glowing halo which is known as an aurora.
Answer:
Cause: Earth’s magnetosphere traps radioactive
solar wind particles in bands around Earth.
Effect: Space travel through the Van Allen
belts is dangerous.
Cause: Earth is surrounded by a magnetic field.
Effect: Solar wind deflects toward the poles.
Cause: Solar wind particles interact with Earth’s
upper atmosphere.
Effect: An aurora is created.
I got it right for Plato :)
What does it mean when we say that DNA replication is semiconservative ?
Answer:
Basically, when people say that DNA replication is semi-conservative they are saying that two identical copies are being made from the original DNA strand.
Explanation:
The two new strands contain one side of the original DNA and another side of synthesized pair.
how many codons specify 5 amino acids?
Answer:
20, Im not completely sure tho
Explanation:
2) If the foliation on a rock is running north-south what direction is the tectonic pressure coming from?
Answer:
if the foliation on a rock is running north-south, the pressure might be vertical (for instance, up to down)
Explanation:
The pressure is the second most principal factor that influences metamorphic rocks. It originates from the weight of the own materials, their densities, and the deepness.
Litostatic pressure originates from the weight of materials in the interior of the crust.
Pressure generates alignment of materials (foliation and schistosity) and mineral rotation.
There are different types of metamorphism.
Dynamic metamorphism is the one where pressure is the principal factor. It generates by tectonic conditions, and it presents mainly in failure or fracture areas. It provokes trituration and recrystallization of minerals.
Classification of the metamorphic rocks according to their structure:
GranulationRecrystallizationMetasomatismMassiveFoliationFoliation refers to dynamic metamorphism, where pressures act and minerals orientate perpendicular to the pressure direction.
According to this concept, if the foliation on a rock is running north-south, the pressure might be vertical (for instance, up to down) while minerals' weight helping in the process of foliation.
If the foliation on a rock is running north-south, the tectonic pressure is coming from a vertical direction.
What is a foliation?Foliation on a rock means continuous multi layering on a metamorphic rock.
These layers can be thin as a sheet of paper.
Foliation occurs when the plain or elongated minerals inside a rock are pressed together and aligned.
Thus, If the foliation on a rock is running north-south, the tectonic pressure is coming from a vertical direction.
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please help! i dont really get this at all
Answer:
The slope between the red points is 2/4 (simplified it is 1/2). The slope between the green points is 4/8 (simplified it is 1/2). This shows that by taking ANY two points on the line, you will find the same slope.
Limiting factors that affect large, dense populations more than small, scattered
populations are called 
_______
Answer:
Density dependant limiting factor
Explanation:
Each different section of the chromosome represents a _____
*wasnt given any answers
What occurs during glycolysis?
Answer:
Glycolysis is the process in which one glucose molecule is broken down to form two molecules of pyruvic acid science my fav class btw thats how i know it
Explanation:
vitamin(a) retinol function on the body
Answer: Function. Vitamin A helps form and maintain healthy teeth, skeletal and soft tissue, mucus membranes, and skin. It is also known as retinol because it produces the pigments in the retina of the eye. Vitamin A promotes good eyesight, especially in low light. Vitamin A (retinol) is ingested as either retinyl esters or carotenoids and metabolized to active compounds such as 11-cis-retinal, which is important for vision, and all-trans-retinoic acid, which is the primary mediator of biological actions of vitamin A
Explanation:
If 22% of a DNA sample is made up of cytosine, C, what percentage of the sample is made up of adenine,
A?
Answer:
28% of Adenine
Explanation:
Chargaff's Rule states that A = T and C = G
Because of that, the sample must have the equation:
A + C = T + G
G must have the same amount as C so,
A + .22 = T + .22
Both sides of the equation must equal each other by .50, so .50 - .22 = .28
.28 x 100 = 28%
If 22% of a DNA sample is made up of cytosine, C, the percentage of the sample is made up of adenine, A is 28%
What is DNA?The DNA sequence is the sequence or pairing of DNA bases. RNA and DNA both are genetic materials and both are made up of nucleic acids made up of deoxyribose acid and iron is made up of ribonucleic acid.
DNA and RNA both contain four bases that are joined with hydrogen bond RNA contain uracil in the place of thymine and DNA contain timing all other bases are the same.
Chargaff's Rule states that A = T and C = G
Because of that, the sample must have the equation:
A + C = T + G
G must have the same amount as C so,
A + .22 = T + .22
Both sides of the equation must equal each other by .50, so .50 - .22 = .28
.28 x 100 = 28%
Therefore, the percentage of the sample is made up of adenine, A is 28%
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PLEASE HELP! IM DOING A TEST!!
What do Vaccines do?
Answer: vaccines help to protect us from a disease by giving our immune system a sample so that when the real disease comes, your body will be ready to fight it off.
Explanation:
Hope that helps!
Select ALL of the following that are directly involved with making a protein
Ribosome
Cell Membrane
DNA
Cytoplasm
Cell Membranes,Ribosome, Cytoplasm are used to make protein
Explanation:
Proteins are formed in a condensation reaction when amino acid molecules join together and a water molecule is removed. The new bond formed in protein molecules where amino acids have joined (-CONH) is called an amide link or a peptide link.
hope it will help you
Give an example of central heating and of local heating.
Answer:
A central heating system provides warmth to the whole interior of a building from one point to ... Institutional heating systems (office buildings or schools, for example) can use low-grade, inexpensive
An alternative to district heating would be to build a small district heating plant together with your neighbours, which is known as local heating or joint heating. ... The local heating system also includes a network of pipes and a common boiler plant that delivers heat through the pipework to the single-family houses.
Explanation:
-Eijiro <3
suppose you find a paper clip stuck to a magnet you pull off the paper clip and move it to a short distance away from the magnet what happened to the magnetic Force between the magnet and the paper clip A. it disappears B. it gets stronger C. it gets weaker D.it stays the same
Answer: C
Explanation: it gets weaker because there not as close together
PLEASE HELP ME
The greater the biodiversity in an ecosystem the
A. less likely the ecosystem is to survive
B. more likely the ecosystem will survive
C. less valuable it is to human, for various products
D. the more similar it is
Answer:
I am pretty sure the answer is B
- I'm sorry of its not correct
Describe rainforests. Include how much rain they get, general location and temperature.
Answer:
The average temperature in tropical rainforests ranges from 70 to 85°F (21 to 30°C). The environment is pretty wet in tropical rainforests, maintaining a high humidity of 77% to 88% year-round. The yearly rainfall ranges from 80 to 400 inches (200 to 1000 cm), and it can rain hard
Explanation:
What is the genotype ratio?
Answer:
The genotypic ratio shows the number of times a characteristic of an organism will be seen in the offspring when genes for certain traits are crossed.
Explanation: hope this helps :p
HELP ASAP I AM SO STUCKKKK!!!!!!!!!!!!!!!!!!!!!
In recent decades, extinction rates have been significantly lower than normal.
-true
-false
Answer:
TRUEEEEEE IS THE ANSWER MADAM
Kingdom protista contains organisms that do not fit into other Eukarya Kingdom. Explain 3 ways that protists are different from animals, plants and fungi.
Explanation:
Protists are eukaryotes, and most are single-celled. You can think about protists as all eukaryotic organisms that are neither animals, nor plants, nor fungi.
protists is a paraphyletic name for unicellular Eukaryota organisms.
Why are healthy bodies of water important to our Earth as a system?
Answer At heart, all life on Earth uses a membrane that separates the organism from its environment.
Answer:
At heart, all life on Earth uses a membrane that separates the organism from its environment. ... In this regard, water is essential simply because it's a liquid at Earth-like temperatures. Because it flows, water provides an efficient way to transfer substances from a cell to the cell's environment
Explanation:
Put this In a simpler form
HELP MEEE,!!!!! PLEASE
Answer:
C
Explanation:
spindle fibers are important during metaphase. division stops without them.