Answer:
D. Collect a large sample number
Explanation:
With a larger sample number, that means that more people participated and gave the correct answer. If you constantly change the variable, the answer may always be the same but because of the variable you changed.
In an experiment you, the researcher, remove calcium ions from the system. What would be a likely consequence of the lack of calcium on muscle contraction
Answer:
Wish I could help
Describe convection currents
Answer:
it is a process whereby energy moves from one place to another
Explanation:
What are differences between the structures ofDNA and RNA?
Sources:
The Differences Between DNA and RNA - ThoughtcoDifference Between DNA and RNA - ByjusI need help with one paragraph.
Answer:
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Explanation:
Which of the following best explains what will happen if the blood gets too cold? A) It will have a high viscosity and increased resistance. B) It will have a low viscosity and increased resistance. C) It will cause low blood pH and decrease resistance. D) It will change the shape of blood cells and decrease resistance.
It will have a high viscosity and increased resistance.
Effect of temperature on bloodLow temperatures cause narrowing of blood vessels and arteries which leads to restricting blood flow and reducing oxygen to the heart.
Our heart must pump harder to circulate blood through the blood vessels which results in increasing of our blood pressure and heart rate.
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Answer:
The correct answer is A
Explanation:
i got it correct on my flvs exam
A place where animals and plants are protected is called
A) an ecosystem
B) a refuge
C) a sanctuary
D) both B and C
Hello! can someone help me w this pls
when they find these similarities they conclude that these organisms have a common
Answer:
Every living creature has DNA
Explanation: hope this helps
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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.
Which are the bones of the axial skeleton? Check all of the boxes that apply.
Answer:
Skull (cranium)
Skull (facial)
Auditory ossicles (three in each ear - not shown)
Hyoid (neck bone, aids speech - not shown)
Vertebral column
Thorax (sternum)
Thorax (ribcage)
Explanation:
what is a spygnomanometer ?
Answer:
an instrument for measuring blood pressure
Explanation:
an instrument for measuring blood pressure typically consisting of an inflatable rubber cuff which is applied to the arm and connected to a column of mercury next to a graduated scale, enabling the determination of systolic and diastolic blood pressure by increasing and gradually releasing the pressure in the cuff.
birds and mammals are both endothermic. i.e. they maintain body temperature internally through metabolism rather than from the environment. how would you explain this, given the position of the two groups of animals on the phylogenetic tree?
On the phylogenetic tree, (a diagram used to show relatedness among organisms) the birds and mammals are closely related to each other and they both are characterized as endothermic.
Given the position of the two group of animals on the phylogenetic tree, their similarity with regards to maintaining body temperature is due to the fact that their evolution involves a more recent ancestor compared with the other vertebrates.
As organisms evolve beginning from invertebrates through to vertebrates, the body system becomes more complex and as they evolve within the vertebrate group.
Some vertebrates like reptiles and amphibians that were dependent on the environment to regulate their temperature while others like birds and mammals forms complex system that enable them live on land and regulate their temperature independent of the environment.
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Biology cell division
What are the answers to this chart
The cell spends most of the time in the interphase, which is in the G1, S, and G2 phases, and approximately 22 hours out of 24 hours, with the rest being 1–2 hours, are spent in the division phase.
What is the time spent in the cell cycle?
The cell enters the cell cycle, and the first stage is the G1 phase, where the cell grows and spends a lot of time nearly 11 hours and then the cell enters the S phase. In the S phase, the DNA replicates and spends nearly 7 hours, and then in the G2 phase, 3 to 4 hours are spent by the cell, with the remaining 1 to 2 hours spent in the M phase, also called the mitosis or division phase.
Hence, cells spend most of the time in the interphase, which is in the G1, S, and G2 phases, and approximately 22 hours out of 24 hours, with the rest being 1–2 hours, are spent in the division phase.
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Which option(s) correctly describes chromosomes?
Chromosomes consist of tightly coiled DNA wrapped around proteins called histones
Each chromosome has one gene
Chromosome pairs contain completely different genes
Most human cells have two copies of each chromosome - one from each parent.
Answer:In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.
Chromosomes are not visible in the cell’s nucleus—not even under a microscope—when the cell is not dividing. However, the DNA that makes up chromosomes becomes more tightly packed during cell division and is then visible under a microscope. Most of what researchers know about chromosomes was learned by observing chromosomes during cell division.
Each chromosome has a constriction point called the centromere, which divides the chromosome into two sections, or “arms.” The short arm of the chromosome is labeled the “p arm.” The long arm of the chromosome is labeled the “q arm.” The location of the centromere on each chromosome gives the chromosome its characteristic shape, and can be used to help describe the location of specific genes.
The ancestors of modern-day fish were vertebrate chordates. Vertebrate chordates are believed to have evolved from invertebrate chordates, which were similar to modern-day tunicates.
What change must have occurred during the evolution from invertebrate chordates to vertebrate chordates?
A.
A backbone evolved to enclose the notochord, which develops from the spinal cord.
B.
An endoskeleton evolved to enclose the spinal cord, which develops from the notochord.
C.
An endoskeleton evolved to enclose the dorsal nerve cord, which develops from the notochord.
D.
A backbone evolved to enclose the spinal cord, which develops from the dorsal nerve cord.
Answer:
The correct answer is option B, that is, an endoskeleton evolved to enclose the dorsal nerve cord, which develops from the notochord.
Explanation:
It has been discovered that the ancestors of the modern-day fish were vertebrate chordates. The vertebrate chordates are considered to have evolved from the invertebrate chordates that are identical to the present day tunicates. It has been found that in vertebrates the endoskeleton has evolved to encompass the dorsal nerve cord that has been developed from the notochord (a characteristic of invertebrates).
Which nerve is responsible for hiccups?
Answer:
b. Phrenic nerve
Explanation: is correct
What happens to the peak wavelength in the blackbody spectrum as the temperature of a star increases?
A. The peak wavelength decreases.
B. The peak wavelength increases.
C. The peak wavelength doesn't change.
D. The peak wavelength decreases and then increases
Answer:
D
Explanation: the peak wavelength in the blackbody decreases
A student is researching the inheritance patterns of different traits in chickens. She hypothesizes that red feathers are dominant over black, and the trait for crests are dominant over non-crested. She performs a test cross to confirm her hypothesis. To produce the F1 generation, she crosses two parents-- a chicken that is homologous for traits showing red and crested and a chicken that is homologous for traits showing black and non-crested. Which ratio best represents the phenotype of the F2 generation
9:3:3:1
1:1:1:1
2:2:1:1
16:0
Answer:
9:3:3:1
Explanation:
In this inheritance pattern, the ratio that best represents the phenotype of the F2 generation is 9:3:3:1. Thus, the correct option for this question is A.
What is a Phenotype?A phenotype may be defined as the mechanism of expressing genotypes in the form of traits. In more simple words, it is also characterized as the morphology or physiology which comes due to the combination of alleles.
If a trait of red feathers is denoted by R and the trait of black feathers is denoted by r, then R > r. Similarly, a trait of crests is denoted by C and the trait of non-crested is denoted by c, then, C > c.
Now, RRCC is crossed with rrcc, the F1 offspring have the genotype RrCc with the phenotype of red feathers with crests. Now, RrCc is selfed, it produces the ratio of 9:3:3:1. This is an example of a dihybrid cross.
Therefore, in this inheritance pattern, the ratio that best represents the phenotype of the F2 generation is 9:3:3:1. Thus, the correct option for this question is A.
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Which part of the vascular system functions as a blood reservoir and contains over 60% of the body's blood
Answer:
Veins are also called capacitance vessels because they contain 60% of the body's blood volume.
Explanation:
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There are two types of reproduction, sexual and asexual Sexual reproduction involves two parents, while asexual reproduction only involves one,
Sort the reproductive processes below according to whether they are asexual or sexual.
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Creation of an egg
Creation of fruit
Mushrooms producing spores
Production of seeds
Stem cuttings of plants
Sexual
Asexual
Budding in yeast
drag and drop answer here
drag and drop answer here
Answer:
Creation of egg- Sexual
Creation of fruit - Sexual
Mushrooms producing sporea - Asexual
Production of seed - Sexual
Stem cutting - Asexual
Budding in yeast - Asexual
What invertebrate animals are the ancestors of tetrapods
A)jellyfish
B)cartilaginous fish
C)jawed fish
D)jawless fish
Answer:
D I believe
Explanation:
damage to the sinoatrial node in humans would ________.
Answer:
have a decrease in blood pressure
Explanation:
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Damage to the sinoatrial node in humans can result in irregular heartbeats, abnormal heart rhythms, decreased cardiac output, and an increased risk of sudden cardiac arrest. Prompt medical evaluation and appropriate treatment are crucial to manage these effects and maintain a healthy heart rhythm.
Damage to the sinoatrial (SA) node in humans would result in disruptions to the normal electrical conduction system of the heart. The SA node is often referred to as the "natural pacemaker" of the heart because it initiates the electrical impulses that regulate the heartbeat. Here's how damage to the SA node would affect the heart:
1. Irregular Heartbeat: The SA node is responsible for setting the pace of the heartbeat. If it is damaged, the heart may beat too fast, too slow, or irregularly. This can lead to symptoms like palpitations, dizziness, and shortness of breath.
2. Abnormal Heart Rhythms: Without the SA node functioning properly, other areas of the heart may take over the role of generating electrical impulses. However, these impulses may not be coordinated or synchronized, resulting in abnormal heart rhythms such as atrial fibrillation or heart block.
3. Decreased Cardiac Output: The SA node helps regulate the timing of the heart's contractions, ensuring efficient blood flow throughout the body. Damage to the SA node can disrupt this coordination, leading to decreased cardiac output. This means that the heart may not be able to pump enough blood to meet the body's needs, resulting in symptoms like fatigue and weakness.
4. Risk of Sudden Cardiac Arrest: In severe cases, damage to the SA node can increase the risk of sudden cardiac arrest. Without the SA node's ability to regulate the heartbeat, the heart may stop pumping blood effectively, leading to a life-threatening emergency.
5. Treatment Options: Treatment for damage to the SA node depends on the severity and symptoms. In some cases, medication or cardiac devices like pacemakers may be used to regulate the heart's rhythm and ensure proper electrical conduction.
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The farm business has decreased for years
due to an increase in disease and pests.
What is one way to increase the production of
crop for the farmers?
A.Plant genetically modified crops.
B.Use water treated with disease control substances to
water the crops.
C.Fertilize the farming land.
D.Increase the use of pesticides to prevent pest.
organisms composed of one or more cells are known as
Answer:
multicellular organisms
Explanation:
Multi means many or more than one and so multicellular literally means many cells.
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Answer: water cycle: evaporation condensation precipitation
carbon cycle: fossil fuel combustion, co2 in atmosphere, photosenthises prob spelled wrong
Explanation nitrogen cycle bacteria, nitrogen separting bacteria n2, nitrogen in the air, nitrate salts back to bacteria
pro wrong but there ya go
Select two options.
What happens during cell respiration?
O The cell takes in oxygen.
O The cell releases oxygen.
O The cell takes in carbon dioxide.
O The cell releases carbon dioxide.
O The cell splits.
What substances in food provide organisms with energy?
Answer:
A food is something that provides nutrients. Nutrients are substances that provide: energy for activity, growth, and all functions of the body such as breathing, digesting food, and keeping warm; materials for the growth and repair of the body, and for keeping the immune system healthy.
Explanation:
Answer: Carbohydrates
Explanation: Because of the starches and sugars in food, that gives your body‘s main sources of energy.
transcription starts with ____ and makes ____ with the aid of ____________
Answer:
transcription starts with Initiation/the nucleus/DNA and makes mRNA with the aid of Polymerase RNA enzyme
Explanation:
Transcription is the process in protein synthesis consisting of a starting process of initiation where the nucleus hosts the creation of an mRNA sending the coding message to the ribosome, but the starting process is the Polymerase binding to a site on the DNA strand, then it makes the mRNA through the other steps in transcription.
Which of the following nerves is responsible for hearing and balance?
Answer:
b. Vestibulocochlear nerve
Explanation: is correct
state the expressed power you think is the most important and explain why you think it is the most important.
Answer:
The most important powers include the power to tax, to borrow money, to regulate commerce and currency, to declare war, and to raise armies and maintain the navy. These powers give Congress the authority to set policy on the most basic matters of war and peace.
Explanation: If I am wrong then i am sorry
Can someone help me with this please? i would really appreciate it
Answer:
I'll try, what is it?
Explanation: