Which model of replication did the actual results of the Meselson-Stahl experiment support? Explain your answer.
Answer:
Semi-conservative replication
Explanation:
After the double-helix discovery of Watson and Crick, there were three possible models about the DNI replication:
The Conservative model stated that the two strands of DNI together were the template of another new molecule. The final product was the original double-stranded molecule and the new molecule. The semi-conservative model stated that the original DNI molecule separated into two strands, and each of them served as a template for the synthesis of a new complementary strand. The replication product would be two double-stranded DNA molecules, each carrying an original strand a new one. The Dispersive moles stated that the replication product would be two molecules made by a mixture of segments of the original and the new molecules.Meselson and Stahl joined to discover which of the models was the correct one. To do it they used E. coli and Nitrogen isotopes.
First, they extracted DNI from bacteria grown in a medium with N¹⁴ and got its density band by centrifugation. Then they grew bacteria in a medium with N¹⁵, extracted their DNI molecules, centrifugated them, and got the density band, which was heavier than the firsts ones. The researchers then transferred bacteria grown in medium with N¹⁵ to a medium with N¹⁴, and they allowed only one replication process to occur. DNI was extracted and centrifugated again, and a new band appeared. This band was an intermediate form between bands of DNI-N¹⁵ and DNI-N¹⁴.This event eliminated the conservative model. If this model were correct, the expected result would be to get two bands: one corresponding to the density DNI-N¹⁵ and the other corresponding to the density DNI-N¹⁴.
Bacteria grown in a medium with N¹⁵ and then transferred to a medium with N¹⁴ were finally allowed to replicate twice. Their DNI was extracted and centrifugated. The result was two bands: one of them coincided with the intermediate band, and the other one with the DNI-N¹⁴.This result was conclusive because if the dispersal model were correct, these two bands should not appear, as all the DNI strands would have part of the original molecule.
With this experiment, Meselson and Stahl proved that the correct replication model was the semi-conservative one.
Is Biotechnology ethical ? Why is it or why is it not ?
Answer:
yes , biology is ethical.
Explanation:
Ethical issues that arise from modern bio technologies include the availability and use of privileged information, potential for ecological harm, access to new drugs and treatments, and the idea of interfering with nature
Which type of tectonic plate interaction forms a mid ocean ridge?
Answer:
Divergent plate
Explanation:
A semi ocean ridge is formed by the interaction of divergent boundaries. Around divergent plate boundaries, as additional sea floor is formed as the Earth's tectonic plates expand outward, half ridges form. Igneous material grows to the ocean bottom when the plates split, resulting in massive basalt volcanic activity.
Show how artificial selection could be used to develop a new breed of wheat with higher fiber content
Answer:
get wheat that has the desired content (in this case high fiber content)
breed them
amongst the offsprings/ wheat produced, select the ones with highest fiber content
breed them
repeat this process for many generations
Explanation:
Artificial selection is a process of selective breeding where humans choose certain traits to breed for in plants or animals.
What would happen in case of wheat?In the case of wheat, we could use artificial selection to develop a new breed of wheat with higher fiber content by selecting individual plants with the desired traits and breeding them together over several generations.
Below are the steps:
Identify wheat plants with higher fiber content: The first step would be to identify individual wheat plants that have naturally higher fiber content. This could be done by analyzing the fiber content of different varieties of wheat and selecting those with the highest fiber content.
Crossbreed the selected plants: Once we have identified wheat plants with high fiber content, we can crossbreed them to create a new hybrid variety. This involves taking the pollen from one plant and fertilizing the flowers of another plant with it. The resulting seeds will have a mix of genetic traits from both parent plants.
Select the desired traits in the hybrid plants: After the hybrid plants have grown, we would need to evaluate them for their fiber content. We would select the plants with the highest fiber content and use them as parents for the next generation of plants.
Repeat this process for several generations: The process of selective breeding would be repeated over several generations, with each generation being evaluated for fiber content and only the plants with the highest fiber content being used for breeding. This would increase the likelihood of producing a new wheat variety with consistently high fiber content.
Test and refine the new wheat variety: Once a new wheat variety with higher fiber content has been produced, it would need to be tested for its nutritional value, taste, and other characteristics. If the new variety meets the desired criteria, it could be released for commercial production.
In summary, artificial selection can be used to develop a new breed of wheat with higher fiber content by selectively breeding individual plants with high fiber content and repeating the process over several generations until a new variety with consistently high fiber content is produced.
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3. How does the atmosphere benefit life on Earth?
A. It provides light to Earth
B. It breaks down dead plants and animals.
C. It filters out certain harmful rays from the Sun
Answer:
C. It filters out certain harmful rays from the Sun
Explanation:
A: the Sun is what provides light to Earth
B: decomposers break down dead plants and animals
So C: It filters out certain harmful rays from the Sun, is correct
As an embryo developed, identical cells give rise to specialized cells that platform different functions.
Answer:
As an embryo develops, identical cells give rise to specialized cells that perform different functions.
Explanation:
As an embryo develops, the cells divide, giving new ones. As the cells grow and continue to reproduce themselves, they differentiate, becoming specialized cells. These cells will be located in a particular part of the embryo and will perform a specific function. The shape, size, and organelles vary according to their role.
Whích DNA strand is complementaryto the DNA strand TAC CTA AGT GCA
A. ATG GAT TCA CGT
B. GTA TAG ACT TGC
C. GGG CAG CAG GAT
D. TCA CGT GAT ATG
Answer: A
Explanation:
G is opposed to C
And C is opposed to G
T is opposed to A
And A is opposed to T
Which example is classified as a body fossil?
Answer:
The fossils of bones, teeth, and shells are called body fossils.
Explanation:
Why are cells of different shapes and sizes? Give suitable examples.
Answer:
Some cells are different shapes as they have different ways of attempting to pass through the immune system they are different sizes as some of them want to make sure that the white blood cells cannot swallow them as easily at that point antitoxins are released to break them down
Explanation:
Which of the following best represents the correct sequence of letters in Photosynthesis? *
A. 1
B. 2
C. 3
D. 4
Answer:
I think it's B
Explanation:
I hope this helped :)
2- Clasifica los siguientes sistemas en abierto, cerrado o aislado:
a. una cazata de helado c. una lata de arvejas e. un vaso con jugo
b. una bolsa de 1kg de arroz sin abrir d. un termómetro f. un perro
3- Clasifica los siguientes sistemas en homogéneo y heterogéneo e indica el número de fases:
a. limonada con hielo c. agua y aceite e. agua gasificada
b. agua y acetona d. tierra, arena y piedras f. café con leche
4- En un laboratorio se realiza un experimento para estudiar la flotabilidad de cuerpos
en el agua.
a. Indica qué partes componen el sistema y cuál es el ambiente.
b. Clasifica el sistema como abierto, cerrado o aislado.
c. ¿En qué estado físico está cada componente del sistema?
d. ¿Cuántas fases tiene?
e. ¿Es homogéneo o heterogéneo?
5- El recipiente de la imagen tiene agua coloreada y está tapado.
a. Identifica qué partes componen el sistema.
b. Clasifica el sistema en abierto, cerrado o aislado.
c. ¿El sistema es homogéneo o heterogéneo?
d. Si enfriamos el recipiente hasta obtener hielo,
¿cambiará la masa del sistema? Justifica
6- Se está estudiando la vida de los peces en una pecera que se encuentra encima de una mesa en el laboratorio.
a. Dibuje lo descrito arriba y señale cuál es el sistema, el límite y cuál es el ambiente.
b. Clasifique el sistema según la interacción con el ambiente, justificando su respuesta.
c. ¿Es homogéneo o heterogéneo?
Answer:
Las respuestas se dan a continuación.
Explicación:
1) Una búsqueda de helado y un vaso con jugo es un sistema abierto, un perro es un sistema aislado mientras que una bolsa de 1 kg de arroz sin abrir, un termómetro y una lata de guisantes es un sistema cerrado.
2) la limonada con hielo, el agua carbonatada, el agua en acetona y el café con leche son sistemas homogéneos mientras que el agua y el aceite, la tierra, la arena y las piedras son sistemas heterogéneos.
3) El recipiente de la imagen tiene agua coloreada y está tapado.
B. el sistema está cerrado.
C. El sistema es homogéneo.
D. Si enfriamos el recipiente a hielo, la masa del sistema no cambiará.
4- Se estudia la vida de los peces en una pecera que se encuentra sobre una mesa en el laboratorio.
a. El sistema es abierto y el medio ambiente es acuático.
B. Es un sistema heterogéneo.
A metabolic waste of algae that can be recycled for use in cellular respiration is A.oxygen
B.sodium
C.organic acid
D.carbon dioxide
como entra la piedra caliza en la fabricación del vidrio y del cemento?
Answer: Fabricación de Cemento: en este proceso la piedra caliza es la base del cemento, y este se crea por la combustión de una mezcla de la piedra caliza y otros materiales, aportando la propiedad de dureza.
Espero que esto ayude
why is the same of cell membrane is equal in both plant cell and animal cell
Answer:
When the cell duplicates it still has the same exact membrane so when it is done duplicating it should have the same exact amount of membrane
Explanation:
i need help please????
Answer:
a
Explanation:
Hell p please
Directions: Explain where each part of the directional terms are
located:
A. Body planes
1. Sagittal
2. Mid-sagittal
3. Coronal/frontal
4. Transverse/horizontal
B. Directional terms
1. Superior
2. Inferior
3. Anterior
4. Ventral
5. Posterior
6. Dorsal
7. Medial
8. Lateral
9. Proximal
10. Distal
11. Superficial
12. Deep
C. Body cavities
1. Dorsal
2. Cranial
3. Spinal
4. Thoracic
5. Abdominal
6. Pelvic
D. Quadrants
1. Right upper quadrant (RUQ)
2. Left upper quadrant (LUQ)
3. Right lower quadrant (RLQ)
4. Left lower quadrant (LLQ)
Answer:
A. Body planes
1. Sagittal: cut along the lengthwise plane of the body. divides left and right parts.
2. Mid-sagittal: cut exactly down the median. divides left and right parts equally. (would cut vertically down the nose)
3. Coronal/frontal: divides the body into anterior and posterior parts
4. Transverse/horizontal:cut along the lengthwise plane. divides anterior and posterior. (coronal section)
B. Directional terms
1. Superior: toward the head end or upper part of a body structure. above. (AKA cranial or cephalad) The face is superior to the neck.
2. Inferior: away from the head end or toward the lower part of a structure or the body. (AKA caudal) The navel is inferior to the chin.
3. Anterior: toward or at the front of the body. (AKA ventral). The windpipe (trachea) is anterior to the esophagus.
5. Posterior: toward or at the backside of the body. (AKA dorsal). The heart is posterior to the sternum.
7. Medial: toward or at the midline of the body. The bridge of the nose is medial to the eyes.
8. Lateral:away from the midline of the body. The eyes are lateral to the nose.
9. Proximal: close to the origin of the body part or point of attachment of a limb.
10. Distal: farther from the origin of a body part or the point of attachment of a limb. the foot is distal to the knee.
11. Superficial: toward or at the body surface. (AKA external). The skin is superficial to the muscles.
12. Deep:away from the body surface (AKA internal). The intestines are deep to the spine.
C. Body cavities
1. Dorsal: consists of two subdivisions which are continuous with each other: cranial cavity and spinal cavity
2. Cranial: space inside the skull
3. Spinal: extends from cranial cavity almost to the end of the vertebral column. protected by the vertebrae
4. Thoracic: separated from rest of ventral cavity by the diaphragm. contain heart, lungs, etc that are protected by the rib cage
5. Abdominal: contains stomach, liver, intestines, etc
6. Pelvic: contains reproductive organs, bladder, and rectum
D. Quadrants :
1. Right upper quadrant (RUQ): Lobe of the liver is located and gallbladder. contains liver, gallbladder, small and large intestines
2. Left upper quadrant (LUQ): Main portion of the stomach. contains stomach, pancreas, spleen, small and large intestines
3. Right lower quadrant (RLQ): The Cecum, appendix, and part of the small intestine are located. contains small and large intestines, appendix, female ovary and uterus, bladder.
4. Left lower quadrant (LLQ): Descending colon. Contains small and large intestines, female ovary and uterus, bladder
What is the term for a structure that has no use in an organism?
A.Homologuos
B.Index
C.Vestigial
D.Sedimentary
The answer you're looking for is C. Vestigial.
Vestigial structures are structures that have no clear purpose and tend to be leftover pieces from a previous ancestor.
Hope this helps; have a great day!
Which of the following best describes the relationship between the new moon phase
and constellations?
A During the new moon phase, constellations take on different shapes due to a lack
of moonlight
B During the new moon phase, constellations are on the same side of the earth as
the sun
с
During the new moon phase, constellations are easier to see due to a lack of
moonlight
D
During the new moon phase, constellations are easier to see due to increased
sunlight
Answer: c
Explanation:
when there is lack of moonlight its easy to see star light
During the new moon phase, constellations take on different shapes due to a lack of moonlight. So, the correct option is A.
What are Constellations?Constellation is define as a group of stars that appears to form a pattern or picture, such as Orion the Great Hunter, Leo the Lion, or Taurus the Bull. Constellations are recognizable patterns that help people navigate the night sky where there are 88 official constellations.
The groups of stars which make an imaginary shape in the night sky are called constellations which are usually named after mythological characters, people, animals and object they resemble in shape. During the new moon phase, constellations take on different shapes due to a lack of moonlight which describes the relationship between the new moon phase and constellations.
Therefore, the correct option is A.
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What could be the reasons that a desert ecosystem can support less populations.
who invented Napiers bone and when
Answer:
John Napier (1550-1617), matemático escocés, inventó dos ábacos multiplicativos que se conocen con los nombres de "huesos de Napier" y "promptuario" respectivamente. Se dieron a conocer en el año 1617 y suponen una aportación fundamental en la historia del desarrollo de los aparatos de cálculo.
Explanation:
Answer:
Explanation:
John Napier a Scottish mathematician invented a calculating device in 1614.
Gressel the Goblin is making an inventory of Darklord Ganondorf’s treasure horde following a raid by some violent fellow named link. The horde now contains only 2150 gems (as in $). Gressel notices that there were twice as many green-gems (worth 1) as blue-gems (worth 5) and 13 fewer blue gems than red-gems (worth 20). How many red, blue and green gems are there remaining in the horde?
➥ Let the number of blue gems be x, green gems be 2x and red gems be x + 13.
According to question,
5x + 1 × 2x + 20(x + 13) = 2150
On solving equation, we get
27x + 260 = 2150
27x = 2150 - 260
27x = 1890
x = 1890/27 = 70 blue gems.
2 × 70 = 140 green gems.
70 + 13 = 83 red gems.
Hence, We have 70 blue gems, 140 green gems and 83 red gems.
Which of the following is a true statement? A. Both electric fields and electric forces maintain their strength at the distance increases. B. Both electric fields and electric forces increase in strength as the distance decreases. C. Electric fields don't change in strength with distance from a charge, but electric forces do. D. Electric forces stay the same as distance changes, but electric fields change.
plz answer this question what is it
Answer:
option(D) is right answer
Explanation:
because human takes oxygen and plants take carbon dioxide
Answer:
well, what we can do here is eliminate what we know. It's not A, because ALL living organisms reproduce. (examples include humans, cows, plants, etc.) for now, until we see the other answers, we will skip b. It can't be C, because on a trusted website, it states that the unified cell theory states that: all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells. Rudolf Virchow later made important contributions to this theory. ... All organisms are made up of one or more cells.
If we take a look at D, It could be true because in another trusted website, it states that Oxygen helps organisms grow, reproduce, and turn food into energy. ... Although other animals may use different organs to breathe with, they all get oxygen into their bodies through respiration. So, Looking back up to B, it seems less likely now that we've viewed everything. D is the answer, I wasn't paying attention earlier, haha.
Hope this helps! brainliest is appreciated :)describe a receptor molecule
Answer:
receptors are chemical structures, composed of protein, that receive and transduce signals that may be integrated into biological systems
Explanation:
Answer:
a protein which binds to a specific molecule. The molecule it binds is known as the ligand. A ligand may be any molecule, from inorganic minerals to organism-created proteins, hormones, and neurotransmitters.
helpppppp pleaseeeeeee
How does an ATP molecule release
energy for cells?
A. hydrolysis
B. breaking the bond between the 2nd and 3rd phosphate
C. removing the ribose sugar
Answer:
B
Explanation:
when one phosphate group is removed by breaking a phosphoanhydride bond in a process called hydrolysis, energy is released.
The ATP molecule releases energy for cells by breaking the weak phosphate bond and converting it to ADP. This process is called A. hydrolysis.
What is the hydrolysis of ATP? Our body requires energy to perform various body activities and functions. This includes muscle contraction, digestion, transportation of molecules etc. This energy comes from the breakdown of ATP. The ATP molecule that is generated during the respiration process is broken down into ADP. This process is called the hydrolysis of ATP. The energy that is released during the breakdown of ATP is used to perform the required functions. Out of the three phosphate bonds, the weak phosphate bond is broken down to fulfil the energy needs of the body.Thus, whenever the cell requires energy, the ATP is broken down into ADP by the process of hydrolysis.
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The maintenance of a self-sustaining ecosystem requires a
A.soil that is acidic
B.constant temperature
C.greater numberof herbivores than producers
D.cycling of materials between organisms and their environment
List 3 main functions of the cutaneous membrane (skin).
Answer:
The cutaneous membrane is the technical term for our skin. The skin's primary role is to help protect the rest of the body's tissues and organs from physical damage such as abrasions, chemical damage such as detergents, and biological damage from microorganisms.
Explanation:
This is leaving an area of birth or activity for another area. Movement causes a change in
population. Leaving is analogous to emigration.
Answer:
Yes.
Explanation:
Yes, Leaving is analogous to emigration because in emigration the person leaves the country permanently and settles in another country for the job. There are many reasons of emigration of a person such as job opportunities in another country, warfare in the country etc. In emigration, the person leaves the country permanently and settles in another country to made his social status better in the society. There are good job opportunities that force people to leave their country.
Why did Darwin see savage competition as a creative process?
Answer: According to Darwin theory of evolution the struggle for existence is considered as major part for competition among living things.
Explanation:
Coexisting species that belong to the same genera compete for same kind of resources for their survival. Some phenotypic variations gives an survival advantage over others. The superior ones dominate the inferior ones and compete for resources. The one who receives the resources like mates, food, shelter, and others the chances of survival also increases considerably.