A student prepares a cell homogenate from spinach leaves. She performs a cell fractionation experiment to determine the centrifugal force (g-force) that will yield the highest percentage of chloroplasts in the pellet fraction. She splits the spinach homogenate into 5 equal parts and centrifuges the parts for 10 min. at 500xg, 1000xg, 1500xg, 2000xg, or 2500xg. She then determines the proportion of chloroplasts in the supernatant and pellet fractions. The dependent variable in the student's experiment is:
Answer:
the proportion/percentage of chloroplasts in the supernatant and pellet fractions
Explanation:
The dependent variable of an experiment is the variable that is measured by an experimenter or the variable that responds to changes made to another variable (independent variable). The dependent variable is dependent on the independent variable.
In this experiment, a student performs a cell fractionation experiment in order to determine the centrifugal force (g-force) that will yield the highest percentage of chloroplasts in the pellet fraction. The centrifugal force is the independent/manipulable variable while the DEPENDENT VARIABLE IS THE PROPORTION/PERCENTAGE of CHLOROPLASTS in the SUPERNATANT and PELLET FRACTIONS.
Which stage of the lytic cycle kills the host cell? A-the injection of the virus’s genetic material B-the replication of the virus inside the host cell C-the release of the replicated viruses D-the attachment of the virus to the host cell
Answer:
C. The release of the replicated viruses
Explanation:
The 5th stage of the cycle, where the virus is released, is the one that kills the host cell.
This is the "Lysis" stage, where the phages are released from the cell and the cell is destroyed from the viruses.
The thoracic cavity contains the ________. It is found ________ to the vertebral cavity.
Answer: The thoracic cavity contains the heart, lungs and many of the main vessels of the circulatory system. It is found anterior to the vertebral cavity.
Explanation:
The thoracic cavity is the second largest hollow space of the body and it is the space limited by the ribs, the vertebral column, and the sternum. It is the upper region of the body starting from the neck and ending where the diaphragm ends. So, it is separated from the abdominal cavity by the diaphragm. It contains 12 ribs, and 7 of them attach directly to the sternum, 3 attach to the sternum via cartilages and 2 do not attach to the sternum at all and are called floating ribs. The cavity contains several organs, such as the lungs, heart, great vessels and esophagus.
The abdominal cavity spaces around the organs are filled with the core muscles that attach to the posterior spine. Besides. the ribs vertically, horizontally and across the abdominal region.
The vertebral cavity is the posterior portion of the dorsal cavity, it contains the spinal cord within the vertebral column, the meninges and the fluid-filled spaces between them. It is formed by the vertebrae through which the spinal cord passes.
The thoracic cavity is anterior to the vertebral cavity, because anterior describes the front or direction toward the front of the body.
A researcher removes all of the mitochondria from a cell. This would likely result in the cells inability to use which of the following molecules
A. The amino acid glycine
B. The nitrogenous base uracil
C. Oxygen
D. Carbon dioxide
I think it’s oxygen but I’m not sure.
Answer:
C. Oxygen
Explanation:
Mitochondria are membrane-bound organelles found in the eukaryotic cells. They are regarded as the "power house" of a cell because of the vital role they play in the synthesis of energy needed to drive an organism's cellular activities. Their role in production of energy (in form of ATP) comes from the cellular respiration that occurs in them.
The kreb's cycle and oxidative phosphorylation of aerobic cellular respiration occurs in the mitochondria. As the name "aerobic" implies, oxygen is strictly involved in the process of respiration occuring in the mitochondria. Hence, if researcher removes all of the mitochondria from a cell, the cell will be unable to use OXYGEN, which is necessary for the cellular respiration in the mitochondria.
Answer:
C. Oxygen
Explanation:
Just took the quiz
why is water considered to be polar molecule
Answer:
Explanation: A water molecule, because of its shape, is a polar molecule. That is, it has one side that is positively charged and one side that is negatively charged. The molecule is made up of two hydrogen atoms and one oxygen atom. The bonds between the atoms are called covalent bonds, because the atoms share electrons. The hydrogen atoms have one electron each.
Because they share those electrons with the oxygen atom, the electrons tend to stay close to the oxygen atom and the outside of the hydrogen atom tends to be positively charged. The oxygen atom has eight electrons. Most of those tend to stay away from the hydrogen atoms, and cause the outside of the oxygen atom to have a negative charge.
Answer: It has one side that is positively charged and one side that's negatively charged.
Draw the noncyclic amp molecule after it has dissolved in water
Answer:
When a cyclic AMP is dissolved in water it loses its bond between its P atom and its main aromatic ring. In the pictures attached, is shown in red the bond that's lost. The cyclic AMP is a messenger involved in many biological processes.
After completing 10 years of experimentation, a scientist reports a
new scientific theory explaining the movement of sand on beaches.
How do you know that this information is valid?
There were too few years of data.
The initial hypothesis was incorrect.
The problem was not important enough.
Theories develop through repeated experimentation.
Answer:
Theories develop through repeated experimentation.
Explanation:
The correct answer would be that theories develop through repeated experimentation.
A theory is internally consistent and is only arrived at after several independent experimentation based on the same phenomenon. That is, when a scientist reports a findings, the reports must have been widely tested by different researchers using the same experiment and arrive at similar findings before they can become a theory.
Hence, the information on the theory explaining the movement of sand beaches is valid because the experiment must have been repeated by several independent researchers and similar results must have been obtained before the theory is arrived at.
What is the difference between a natural resource and an ecosystem service?
Answer:
this is your answer hope this will help you
The main difference between a natural resource and an ecosystem service is that natural resources are tangible and can be directly used by humans, while ecosystem services are intangible and are the benefits that humans get from ecosystems.
How do we explain?Natural resources are often used to provide ecosystem services. For example, water is a natural resource that is used to provide the ecosystem service of regulating temperature.
Ecosystem services are essential for human well-being. They provide us with food, water, shelter, and other essential resources. They also help to regulate our climate, clean our air and water, and provide us with a place to recreate.
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How can blood pressure affect the flow of blood?
Answer:
High blood pressure can damage your arteries by making them less elastic, which decreases the flow of blood and oxygen to your heart and leads to heart disease.
A student observes that a plant has droopy leaves and stems and infers
that the rate of photosynthesis has slowed in the plant. Which statement !
provides evidence to support the student's inference? *
The water pressure in the plant's vacuole is low, and without water, the chloroplasts
cannot convert carbon dioxide to glucose during photosynthesis.
O
The water pressure in the plant's ribosomes is low, and without water, the chloroplasts
cannot convert carbon dioxide to glucose during photosynthesis.
O
The water pressure in the plant's vacuole is low, and without water, the mitochondria
cannot convert carbon dioxide to glucose during photosynthesis.
The water pressure in the plant's ribosomes is low, and without water, the
mitochondria cannot convert carbon dioxide to glucose during photosynthesis.
With which cellular process are ribosomes directly involved?
1 point
Answer:the third one I guess
Explanation:
The rate of photosynthesis can slow down due to low water pressure in vacuoles and without water, the mitochondria cannot convert carbon dioxide to glucose during photosynthesis. So the correct option is C. The ribosomes are directly involved with the translation of mRNA to form proteins.
What is photosynthesis?Green plants and certain other creatures convert light into chemical energy through a process called photosynthesis. Light energy is gathered and utilized during photosynthesis in green plants to change the water, carbon dioxide, plus minerals into oxygen- and energy-rich organic molecules.
It is hard to overstate the role that photosynthesis plays in sustaining life on Earth. There would eventually be little food or other organic materials on Earth if photosynthesis stopped. The majority of life would vanish, and eventually, the atmosphere of Earth would contain almost no gaseous oxygen. Only chemosynthetic bacteria, which can use the chemical energy of certain inorganic substances and are not reliant on the conversion of light energy, would be able to survive in such an environment.
The fossil fuels (coal, oil, and gas) that drive modern society today were created by plants using energy from photosynthesis carried out millions of years ago. Green plants and tiny critters that fed on plants grew more rapidly in the past than they were eaten, and as a result, sedimentation as well as other geological processes buried their remnants in the Earth's crust.
Therefore, the correct option is C.
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Which of the following orientation terms have opposite meanings in humans? *
posterior and intermediate
distal and proximal
superficial and proximal
medial and distal
medial and anterior
Answer:
distal and proximal
Explanation:
The two orientation terms that have opposite meanings in humans would be distal and proximal.
While distal means for a cell, tissue, or organ to be away from a particular point or region, proximal means for a cell, tissue, or organ to be towards a particular point or region. In simpler words, distal means fro while proximal mean to - just like work and opposite.
The following orientation terms have opposite meanings in humans is distal and proxima
The following information should be considered:
The distal means for a cell, tissue, or organ to be away from a particular point or region. While on the other hand proximal means for a cell, tissue, or organ to be towards a particular point or region.Learn more; https://brainly.com/question/1691136?referrer=searchResults
How does adhesion help explain how a sponge or paper towel cleans up spilled water?
Answer:
Adhesion is a property of water that allows it to stick to things. This is why you can clean up spilled water with a sponge or paper towel. The negative and positive charge in water's molecules are attracted to other things with a negative and positive charge.
hope this helps ߷
Among different properties of water, adhesions is a property which allow water to stick to things. Hence, during clean up by paper towel or any sponge can absorb that water molecule.
What are the properties of Water?Water is a chemical molecule having formula H2O where two hydrogen atoms covalently bonded to a single oxygen atom to form one molecule of water.
It is a colorless, odorless, tasteless fluid present in the condensed form due to extensive hydrogen bonds.
It has high melting, boiling points, higher specific heat, thermal conductivity, surface tension, dipole moment, etc.
It maintain the body temperature as it has a high latent heat of vaporization.
Water show acidic and basic behavior, involve in redox reaction and hydrolysis reaction.
As paper towel made up of cellulose sugar molecule, it help in absorption of water.
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If the standard reduction potential of a half reaction is 0.80 V, which statement below is true for this half-reaction to proceed as a reduction A) This half-reaction will proceed if it is coupled to another half-reaction that has a standard reduction potential less than 0.80 V. B) This half-reaction will proceed if it is coupled to another half-reaction that has a standard reduction potential greater than 0.80 V C) This half reaction will proceed if it is coupled to another half-reaction that has a standard reduction potential greater than -0.80 V D) It doesn't matter what half-reaction this is coupled with, it will proceed spontaneously. E) It doesn't matter what half-reaction this is coupled with, it will not proceed spontaneously. subunit of ATP synthase causes conformation changes in the
Answer
The correct is A)
Explanation:
A reduction half-reaction occurs in the cathode. The standard cell potencial (Eºcell) is higher than 0 for a spontaneous reaction. According to this, we deduce:
Eºcell = Eºr(cathode)-Eºr(anode) > 0 (spontaneous)
So, Eºr(cathode) > Eºr(anode) for a spontaneous reaction.
Since Eºr(cathode)= 0.80 V, we can say:
A) This half-reaction will proceed if it is coupled to another half-reaction that has a standard reduction potential less than 0.80 V. TRUE
For example: Eºcell = Eºr(cathode)-Eºr(anode)= 0.80 V - (0.75 V)= 0.05 V > 0
B) This half-reaction will proceed if it is coupled to another half-reaction that has a standard reduction potential greater than 0.80 V. FALSE
It is the opposite of A. For a value greater than 0.80 V, Eºcell will be <0 (non spontaneous)
C) This half reaction will proceed if it is coupled to another half-reaction that has a standard reduction potential greater than -0.80 V. FALSE
This sentence is not true in all cases. For example: a reduction potential of 1.0 V is greater than -0.80 V, so:
Eºcell= Eºr(cathode)-Eºr(anode)= 0.80 V - (1.00 V)= -0.20 V < 0
D) It doesn't matter what half-reaction this is coupled with, it will proceed. FALSE, the reduction potential of the anodic reaction must be lower than 0.80 V.
what prevents the plant cell from constricting in the center during telophase?
Answer:
During telophase, membrane-enclosed vesicles derived from the Golgi apparatus migrate to the center of the cell where the metaphase plate used to be and fuse to form a cell plate. Eventually, the growing cell plate fuses with the existing plasma membrane, producing two daughter cells, each with its own plasma membrane
Explanation:
The explanation regarding the plant cell should be explained below;
The following information should be considered;
At the time of telophase, membrane-enclosed vesicles should be derived from the Golgi apparatus that migrate to the center of the cell.While on other hand, the metaphase plate used to be and fuse to form a cell plate.Learn more: https://brainly.com/question/26115859?referrer=searchResults
importance of snail
Answer:
Snails are good sources of
Iron ProteinVitamin B12Omega -3MagnesiumSeleniumExplanation:
Humans autosomal cells have two copies each of 23 unique chromosomes. Match each of the following cell division events and cell types according to the number of chromatids present. Whereas other events may also be misplaced, you have not matched all of the cell types and events that contain 23 chromatids. A chromatid number of 23 is observed in haploid gametes produced during the second meiotic division.
Answer:
Please see below
Explanation:
The number of chromatids have been stated with the respective event when it occurs in that particular number in the following way:
23 chromatids
primary oocyte arrested prior to ovulation
spermatozoa
46 chromatids
oogonium prior to S phase
92 chromatids
secondary polar body
Which of the following statements about hormone transport and distribution is not true? a. free hormone concentration is not influenced by plasma protein concentration b. hormones bind to certain types of plasma proteins c. hormones can be transported bound to plasma protein or free in the plasma d. only free hormones can diffuse through capillary walls and bind to target tissues e. All of the statements are true.
Suppose you have two genetic variants of a large protein that differ only in that one contains a histidine (side chain pKa = 6.0) when the other has a valine (uncharged side chain).1. Which would be better for separation: gel electrophoresis or isoelectric focusing?A. Gel electrophoresis.B. Isoelectric focusing.2. What would you choose for the separation?A. At a pH of 6.0.B. At a pH above 6.0.C. At a pH below 6.0.D. At any pH value.
Answer:
1. The correct option is B: Isoelectric focusing
2. The correct option is A: At a pH of 6.0
Explanation:
1. Gel electrophoresis is a technique used to separate proteins on the basis of size. Since these two proteins are of similar size (or molecular weight), it will prove to be ineffective to achieve the desired result.
2. Since valine has an uncharged side chain, it will not be affected by pH value so it needs to be maintained at the value where it does not exert direct influence on the protein with histidine.
always carry a microscope using both hands
Eratosthenes determined the circumference of Earth by conducting an
experiment. Put his steps in order as they correlate to the scientific method
The provided question is incomplete, However, the missing part of the question is as follows:
1. State the Problem:
2. Make a Hypothesis:
3. Make Observations:
A) If the sun casts shadows at different angles at the same time of day in different places, we can determine how much Earth curves.
B) In Syene, the sun's rays are vertical at noon. At the same time in Alexandria, the rays are 7.2 degrees from the vertical.
C) How can we prove Earth is round and calculate its circumference?
Answer:
The correct order would be : C, A, and B.
Explanation:
Scientific method for a experiment involves various steps in order such as finding a problem, make a hypothesis, creating observations, conducting experiment, collecting data, analyzing the data, making conclusion and repeating the process.
Option c is a problem about the circumference if earth about how can prove the round and calculate circumference. Option A is hypothesis related to this problem and option C. is observation.
Thus, the correct answer is C, A, B.
Why can’t the world run out of carbon
Answer:Simple carbon is everything that is alive dead man even the planet over time became part carbon dioxide
Explanation:it just is
What kind of questions do biologists attempt to answer?
Answer:
Questions about the living world
Explanation:
I just took the test
Anorexia nervosa has been associated with a primary dysfunction of which structure of the brain?
Answer:
This is an eating disorder,mostly common in ladies especially in models,where there is morbid fear of getting overweight or adding extra weight and therefore leading to lack of appetite
Explanation:
Anatomically,patience with this condition has Increase in the mass of white and grey matter of the brain.These are the areas of cerebral cortex.There is also increased in the volume of CSF during the examination of the brain of such individual,Cerebrospinal fluid is the protective and nutrient contained fluid which bathes the brain and spinal cord.
Furthermore,there was a decrease in the region of the left hypothalamus which controls hunger,and the left Inferior parietal lobe.The latter controls language perceptions and mathematical computation and image of the body perceptions by the brain.
Belumia nervosa,Binging are other eating disorders
A complex individual that consists of organ systems is known as?
Answer: Organism, Biosphere
Explanation:
Organism. A complex individual that consists of organ systems. Biosphere.
4. Proteins are important to all life and are made up of amino acids containing
carbon, hydrogen, oxygen, and nitrogen. How are proteins essential to life?
Answer:
Proteins are important building block of bones, muscles, cartilage, skin, and blood. Our body uses protein to build and repair tissues. It also use protein to make enzymes, hormones, and other body chemicals.
A group of students is observing these two species of squirrels and forming conclusions about how they are alike and different. Which type of investigation is this group doing.
A. Controlled
B. Experimental
C. Descriptive
D. Comparative
If lactose is a disaccharide, what macromolecule
must it be an example of?
carbohydrate
nucleic acid
lipid
proteine
Answer: carbohydrates
Explanation:
Lactose is a disaccharide and it is an example of a carbohydrate. So the correct option is A.
What is a disaccharide?
A disaccharide can also simply be called a double sugar. It is that type of sugar that is formed when two monosaccharide molecules or simple sugars are combined by the formation of a glycosidic linkage. Disaccharides are soluble in water, like monosaccharides. Sucrose, lactose, and maltose are commonly known disaccharides.
The carbohydrates, which on acid or enzyme hydrolysis, release two molecules of monosaccharides which are either of the same type or different are called disaccharides.
The loss of the water molecule results in the formation of an oxide linkage and after that, the two monosaccharides are formed by that linkage. The joining of two monosaccharide units via an oxygen atom results in the formation of a glycosidic linkage.
Sucrose is the most common disaccharide which gives D -(+)- glucose and D-(-)- fructose on hydrolysis.
Therefore the correct option is A.
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In assessing whether fluoridated water can cause cancer, what do the National Research Council, National Health Service, and Centers for Disease Control and Prevention all agree on?
Osteosarcoma is so rare that there is little need to study the risk of fluoride.
Fluoride should not be added to water according to research from dentists.
There is a need for further research.
Answer: there is a need for further research
Explanation:
The National Research Council, National Health Service, and Centers for Disease Control and Prevention all need further research to agree on. Thus, the correct option is C.
What is Cancer?Cancer may be defined as the uncontrolled rapid division and proliferation of cells. It involves continuous stimulation of growth in cells which undergoes the inhibition of apoptosis.
Due to uncontrolled rapid division and proliferation of cells, there is a formation of tumors occur, which is known as undifferentiated cell mass.
According to the question, all agencies of health and welfare require further research in order to predict any outcome or conclusion about the fact that fluoridated water can cause cancer.
Therefore, the National Research Council, National Health Service, and Centers for Disease Control and Prevention all need further research to agree on. Thus, the correct option is C.
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Which type of cell is more complex?
Answer:
eukaryotic cause it has more stuff than prokaryotic
Explanation:
1. Cell membrane / a. Contain chlorophyll I 2. Cell wall r b. Jellylike liquid inside cells 3. Cellulose c. Carry "blueprints" for new cells 4. Chloroplasts d. Directs most cell activities 5. Chlorophyll e. Stores food and water for the cell 6. Chromosomes f. Holds animal cells together 7. Cytoplasm g. Stiff material in cell walls h. Chemical that helps plants 8. Nucleus ,.., make food 9·~ Vacuole i. Stiff structure around plant cells
Answer:
Cell Membrane / F.
Cell Wall / I.
Cellulose / G.
Chloroplasts / A.
Chlorophyll / H.
Chromosomes / C.
Cytoplasm / B.
Nucleus / D.
Vacuole / E.
Explanation:
Took Biology before. Hope it helps. The way it was copy and pasted made it hard to read.