PLEASEEE HELP!! Ill mark brainlist
How/why does the DNA separate?
Discuss porosity or pores, electricity, DNAS charge & size of DNA pieces. Highlight all the 4 terms
Electrophoresis is a technique commonly used in the lab to separate charged molecules, like DNA, according to size.
Gel electrophoresis is a technique commonly used in laboratories to separate charged molecules like DNA?, RNA? and proteins? according to their size.
Charged molecules move through a gel when an electric current is passed across it.
An electric current is applied across the gel so that one end of the gel has a positive charge and the other end has a negative charge.
The movement of charged molecules is called migration. Molecules migrate towards the opposite charge. A molecule with a negative charge will therefore be pulled towards the positive end (opposites attract!).
The gel consists of a permeable matrix, a bit like a sieve, through which molecules can travel when an electric current is passed across it.
Smaller molecules migrate through the gel more quickly and therefore travel further than larger fragments that migrate more slowly and therefore will travel a shorter distance. As a result the molecules are separated by size.
Gel electrophoresis and DNA
Electrophoresis enables you to distinguish DNA fragments of different lengths.
DNA is negatively charged, therefore, when an electric current is applied to the gel, DNA will migrate towards the positively charged electrode.
Shorter strands of DNA move more quickly through the gel than longer strands resulting in the fragments being arranged in order of size.
The use of dyes, fluorescent? tags or radioactive? labels enables the DNA on the gel to be seen after they have been separated. They will appear as bands on the gel.
A DNA marker with fragments of known lengths is usually run through the gel at the same time as the samples.
By comparing the bands of the DNA samples with those from the DNA marker, you can work out the approximate length of the DNA fragments in the samples.
How is gel electrophoresis carried out?
Preparing the gel
Agarose gels? are typically used to visualise fragments of DNA. The concentration of agarose used to make the gel depends on the size of the DNA fragments you are working with.
The higher the agarose concentration, the denser the matrix and vice versa. Smaller fragments of DNA are separated on higher concentrations of agarose whilst larger molecules require a lower concentration of agarose.
To make a gel, agarose powder is mixed with an electrophoresis buffer and heated to a high temperature until all of the agarose powder has melted.
The molten gel is then poured into a gel casting tray and a “comb” is placed at one end to make wells for the sample to be pipetted into.
Once the gel has cooled and solidified (it will now be opaque rather than clear) the comb is removed.
Many people now use pre-made gels.
The gel is then placed into an electrophoresis tank and electrophoresis buffer is poured into the tank until the surface of the gel is covered. The buffer conducts the electric current. The type of buffer used depends on the approximate size of the DNA fragments in the sample.
Preparing the DNA for electrophoresis
A dye is added to the sample of DNA prior to electrophoresis to increase the viscosity of the sample which will prevent it from floating out of the wells and so that the migration of the sample through the gel can be seen.
A DNA marker (also known as a size standard or a DNA ladder) is loaded into the first well of the gel. The fragments in the marker are of a known length so can be used to help approximate the size of the fragments in the samples.
The prepared DNA samples are then pipetted into the remaining wells of the gel.
When this is done the lid is placed on the electrophoresis tank making sure that the orientation of the gel and positive and negative electrodes is correct (we want the DNA to migrate across the gel to the positive end).
Separating the fragments
The electrical current is then turned on so that the negatively charged DNA moves through the gel towards the positive side of the gel.
Shorter lengths of DNA move faster than longer lengths so move further in the time the current is run.
The distance the DNA has migrated in the gel can be judged visually by monitoring the migration of the loading buffer dye.
The electrical current is left on long enough to ensure that the DNA fragments move far enough across the gel to separate them, but not so long that they run off the end of the gel.
Illustration of DNA electrophoresis equipment used to separate DNA fragments by size. A gel sits within a tank of buffer. The DNA samples are placed in wells at one end of the gel and an electrical current passed across the gel. The negatively-charged DNA moves towards the postive electrode. Image credit: Genome Research Limited
tank.
Mitosis is a type of cell division. organize the images below to show the steps of mitosis.
(QUICK PLZ)
Answer:
i believe its the first
Explanation:
Carol and Sam were using the microscope in science class. They used a dropper to put some pond water on their microscope slide. This is what they saw. "That is something living," said Sam. "I don't think so," said Carol. What do you think? Explain.
options:
This is not alive. It is not moving or responding.
This sample is made of identical units. It is not alive.
This is a multicellular organism made of cells. It is living.
This may have been alive once, but not now because it is not moving.
Answer:
Sam was actually correct. Pond water usually contains microrganisms like bacteria, viruses, and parasites. This is also why people do not drink pond water without getting rid of the impurities.
Explanation:
What is not an example of DNA?
Answer:
AMOGUS
Explanation:
Anything other than DNA is not an example of DNA
I think its B? Can someone explain it to me tho
Explanation:
I think it should be C because increase in temperature increases molecular motion. Therefore the speed of the moving molecules of both enzymes as well as the substrate will be accelerated. This
will enhance the colliding probability for both enzyme active sites and substrate molecules and more collisions occur between the enzyme active sites and substrate molecules generate greater chances for the reaction to occur. This can continue up to a certain point, after which there is a rapid decline in enzyme activity. This point is referred to
as optimum temperature. When the temperature increases beyond the optimum temperature, the hydrogen bonds, ionic bonds and other weak chemical bonds of enzyme active sites may be disrupted.
This will result a change in the shape of the active site of enzyme which will alter the complementary nature of the active site of enzyme molecules. Therefore, the
complementary binding of enzyme active sites and substrate molecules will be prevented. The above event is called as denaturation of enzyme molecules.
Therefore the rate of enzyme catalyzed reaction or in this case, photosynthesis will start to decline when the temperature increases beyond the optimum temperature and stops completely at certain
temperature, although rate of collision will keep on increasing.
which cell type would contain the greatest number of mitochondria?
Answer:
It is generally believed that the cells that have the most mitochondria in them are the muscle cells.
Answer:
Muscle Cell
Explanation:
what is the Purpose Question and Hypothesis of the Lab Report: Identifying Nutrients
Answer:
Oil destroys the insulating ability of fur-bearing mammals,
Explanation:
such as sea otters, and the water repellency of a bird's feathers, thus exposing these creatures to the harsh elements. Without the ability to repel water and insulate from the cold water, birds and mammals will die from hypothermia
Before fossil fuel use became widespread, which of the following did people use for a. energy?
b. wind
c. water
d. animals
e. all of these
Answer: im not 100% but i think its E all
Explanation:
b Explain why animals need plant biomass.
Answer:
its in the type of nutrience they have
Explanation:
Answer:
Plants provide oxygen so are vital to animals in order to survive. Many insects use plants to place their eggs: insects. Or even to protect themselves from the sun. Animals obtain part of their water intake through plants.
Explanation:
hope it helps
Please help me with this! The question on the image
2.
No movement of water would have
occurred if they were isotonic.
3.
A. Side 2B. Side 1A test cross is performed to determine if a specific individual is a carrier. The results generate a 50/50 phenotypic ratio. The test subject was therefore ________.
Answer:
The test subject was therefore, Heterozygous
Energy___ as it transfers from what consumer to the next
Explanation:
Energy Decreases as it transfers from what consumer to the next.
How to determine recombination frequency.
Answer:
= # recombination/total progeny ×100
What is the typical configuration of chromosomes in eukaryotic cells?
Suppose a person uses a microscope to look at a cell from the leaf of a tree.
Which structure would they see that would not be found in a cell from a fingernail?
ribosomes
chloroplasts
cilia
mitochondria
do not put a link
Answer:
chlooplast
Explanation:
because those are the ones that are only in plants and they make photosynthesis
what evidence can be cited from the fossils to reconstruct climate change over time?
Answer: When studying the museum’s collection of plant fossils for information about the climate, Wing and Barclay start with plant leaves.
Roughly 56 million years ago, during a time called the Paleocene Eocene Thermal Maximum (PETM), Earth’s average temperature rose four to eight degrees Celsius in less than 10,000 years. The cause was geologic processes releasing trillions of tons of carbon dioxide into the atmosphere. The dramatic shift in global climate forced massive upheaval in ecosystems around the world.
“It’s the best analogue for the climate change we’re experiencing today,” Barclay said.
Fossil plants and their leaves from the PETM show that ecosystems shifted massively because of the rapid increase in global temperature. But global warming during the PETM did not come from humans. So, scientists today are working on ways to extrapolate information from that period and apply it to the even faster and more drastic events of today.
in the dark, an object is more clearly seen when viewed in peripheral vision than when viewed directly. this phenomenon occurs because the rods located in the retina are:
In the dark, an object is more clearly seen when viewed in peripheral vision than when viewed directly, this phenomenon occurs because the rods located in the retina are: more sensitive in the dark than cones.
The retina extends through the posterior portion of the eyeball is the innermost layer and in it are the photoreceptors: cones and rods.
Rods and cones are the two types of photoreceptor cells in vertebrates that capture light energy (photons) and convert it into electrical signals.
The rods are sensitive to changes in light, since their detection thresholds are low, so they only come into operation when the light intensity is low (scotopic vision or night vision).Scotopic vision has relatively low acuity, as the details of an object cannot be discerned or its color appreciated.On the contrary, cones have a much higher threshold for light, they are responsible for daytime vision (photopic vision) and their mission is to detect colors and shapes (details).Therefore, we can conclude that in the dark, an object is more clearly seen when viewed in peripheral vision than when viewed directly, this phenomenon occurs because the rods located in the retina are: more sensitive in the dark.
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under the biological species concept, what criterion is used to assign populations of organisms to the same biological species?
Answer: According to the biological species concept, organisms belong to the same species if they can interbreed to produce viable, fertile offspring. Species are separated from one another by prezygotic and postzygotic barriers, which prevent mating or the production of viable, fertile offspring. Speciation is the process by which new species form
Which layers would you expect to see a greatere population of decompsers.
Answer:
Explanation:
The bottom
NO LINKS What controls circadian rhythms in humans? Explain how this process works.
Answer:
The circadian rhythms are controlled by a part of the brain called the Suprachiasmatic Nucleus (SCN), or a group of cells in the hypothalamus that responds to light and dark signals. Thid happens when our eyes perceive light, causing our retinas send a signal to our SCN.
If the environment gets cold, humans will often respond involuntarily by shivering in order to:
a. keep body temperature the same as the external temperature
b. increase body temperature
C. decrease body temperature
d. regulate blood pressure
Answer:
increases body temperature
Explanation:
this is because when you shiver your blood vessels contract which then increases your body temperature
If the environment gets cold, humans will often respond involuntarily by shivering in order to increase body temperature. So, the correct option is B.
What do you mean by Environment?An environment may be defined as anything that is present in the surroundings of living entities that is either biotic or abiotic.
The process of shivering causes the blood vessels to contract and relax at a rapid rate to maintain homeostasis. The signals of rapid contractions are sent by the hypothalamus through nerve impulses.
Therefore, the correct option for this question is B.
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The different forms matter can take are referred to as states or countries.
Answer:
Three States of Matter
Learning Objective
Describe the three states of matter
Key Points
Matter can exist in one of three main states: solid, liquid, or gas
The states of matterThis diagram shows the nomenclature for the different phase transitions.
Solids
A solid’s particles are packed closely together. The forces between the particles are strong enough that the particles cannot move freely; they can only vibrate. As a result, a solid has a stable, definite shape and a definite volume. Solids can only change shape under force, as when broken or cut.
In crystalline solids, particles are packed in a regularly ordered, repeating pattern. There are many different crystal structures, and the same substance can have more than one structure. For example, iron has a body-centered cubic structure at temperatures below 912 °C and a face-centered cubic structure between 912 and 1394 °C. Ice has fifteen known crystal structures, each of which exists at a different temperature and pressure.
A solid can transform into a liquid through melting, and a liquid can transform into a solid through freezing. A solid can also change directly into a gas through a process called sublimation.
Liquids
A liquid is a fluid that conforms to the shape of its container but that retains a nearly constant volume independent of pressure. The volume is definite (does not change) if the temperature and pressure are constant. When a solid is heated above its melting point, it becomes liquid because the pressure is higher than the triple point of the substance. Intermolecular (or interatomic or interionic) forces are still important, but the molecules have enough energy to move around, which makes the structure mobile. This means that a liquid is not definite in shape but rather conforms to the shape of its container. Its volume is usually greater than that of its corresponding solid (water is a well-known exception to this rule). The highest temperature at which a particular liquid can exist is called its critical temperature.
A liquid can be converted to a gas through heating at constant pressure to the substance’s boiling point or through reduction of pressure at constant temperature. This process of a liquid changing to a gas is called evaporation.
Gases
Gas molecules have either very weak bonds or no bonds at all, so they can move freely and quickly. Because of this, not only will a gas conform to the shape of its container, it will also expand to completely fill the container. Gas molecules have enough kinetic energy that the effect of intermolecular forces is small (or zero, for an ideal gas), and they are spaced very far apart from each other; the typical distance between neighboring molecules is much greater than the size of the molecules themselves.
A gas at a temperature below its critical temperature can also be called a vapor. A vapor can be liquefied through compression without cooling. It can also exist in equilibrium with a liquid (or solid), in which case the gas pressure equals the vapor pressure of the liquid (or solid).
A supercritical fluid (SCF) is a gas whose temperature and pressure are greater than the critical temperature and critical pressure. In this state, the distinction between liquid and gas disappears. A supercritical fluid has the physical properties of a gas, but its high density lends it the properties of a solvent in some cases. This can be useful in several applications. For example, supercritical carbon dioxide is used to extract caffeine in the manufacturing of decaffeinated coffee.
Phase Changes –What does a phase change look like at the molecular level? This video takes a look at the molecular structure of solids, liquids, and gases and examines how the kinetic energy of the particles changes. The video also discusses melting, vaporization, condensation, and freezing.
Explanation:pa brainliest answer po
Plzzzzz help meeeee plzzzzzzz
Answer:
59 is false and 60 and true
Explanation: I think it is right sorry if it is wrong. I hope this helps
Answer: 1) True 2) True
Explanation:
The ligand that activates the g-protein linked receptor is:
Answer:
When a ligand binds to the GPCR it causes a conformational change in the GPCR, which allows it to act as a guanine nucleotide exchange factor (GEF). The GPCR can then activate an associated G protein by exchanging the GDP bound to the G protein for a GTP.
What happens during metaphase 2 in meiosis?
Answer:
During metaphase II, the centromeres of the paired chromatids align along the equatorial plate in both cells. Then in anaphase II, the chromosomes separate at the centromeres. The spindle fibers pull the separated chromosomes toward each pole of the cell.
which is not involved with an inflammatory Response
A. Fever - increased temperature
B. Slowed blood flow
C. White blood cells move to the area of infected
D. inflammation in area
This is an inflammatory reaction to an infection in the body. Option D is correct.
What is the inflammatory response?When tissues are harmed by toxins, germs, trauma, heat, or any other cause, the inflammatory response (inflammation) ensues. A fever is induced by the body's attempt to destroy any infections with heat.
Histamine, bradykinin, and prostaglandins are among the substances released by injured cells. Because of these substances, blood vessels leak fluid into the tissues, producing swelling.
White blood cells migrate to the affected location to destroy any germs. Because white blood cells are primarily intended to aid in the killing of infections, sending white blood cells to destroy the pathogen is an inflammatory reaction.
Finally, inflammation results from the body's attempt to cleanse the contaminated region of microorganisms. Similar to the label “inflammatory,” the body will frequently create inflammation in an attempt to cleanse the body of any undesirable infections.
Therefore, option D is correct.
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Why does rainfall allow for species riches
HELP PLEASE!
Answer:
The coefficient of variation in aboveground biomass of annuals decreased significantly with increasing annual and growing-season precipitation. Species richness of annuals increased significantly with increasing annual precipitation and growing-season precipitation.
Explanation:
Which of the following statements is true about chromosomes in multicellular organisms?
Choose 1 answer:
A) a chromosome contains numerous DNA molecules.
B) Chromosomes are located in both the nucleus and cytoplasm of the cell.
C) Each chromosome contains a large number of genes.
Answer:
Im not sure but c?
Answer:
The answer is c :)
Name at least 3 different body systems and how they are being used while you walk and eat pizza at the same time. Try to include specific details about the organs in the body systems and how they work together. Please answer using your own words in complete sentences.
HELP ME ASAP PLEASE... 30 POINTSSSS
Answer:
skeletal system, nervous system, and digestive system
Explanation:
our nervous system controls our every movement (walking) and skeletal because it makes up the frame work if not we would be total blobs of jello haha. anyways but then when your eating our digestive system when we swallow if goes through the whole phase of digestive system. and then it has to come out somehow so the digestive system at the end we go ahead and do our business.
hope this helps!
What is the main function of cellulose in plants? Cant pick between B and C