A student prepares a cell homogenate from spinach leaves. She performs a cell fractionation experiment to determine the shortest amount time of centrifugation at 2000xg 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 at 2000xg for 0, 5, 10, 15 or 20 min. She then determines the proportion of chloroplasts in the supernatant and pellet fractions. The controlled variable(s) in the student's experiment is/are:_____.
a. proportion of chloroplasts in each fraction.
b. use of same plant homogenate throughout.
c. time of centrifugation in minutes.
d. g-force of centrifugation.
Answer:
b. use of same plant homogenate throughout.
Explanation:
In an experiment, the controlled variable, also called the CONSTANT is the variable that is kept the same throughout the course of the experiment in order not to influence the result or outcome of the experiment.
In this question, a student performs a cell fractionation experiment to determine the shortest amount time of centrifugation (manipulated variable) at 2000xg that will yield the highest percentage of chloroplasts (responding variable) in the pellet fraction. In this experiment, the variable being controlled is same spinach plant homogenate used throughout.
If green plant cells are incubated in the presence of CO2 molecules containing radioactive carbon atoms, the fate of the carbon atoms can be followed. In an experiment, radioactive CO2 was given for 1 minute to plant cells, and then the cells were examined after 1, 5, 10, 20, and 30 minutes. The following molecules were labeled with radioactive carbon at some point(s): glucose, glyceralde-hyde 3-phosphate, glycine (an amino acid), 3-phospho-glycerate, ribulose 1,5-bisphosphate, and sucrose.
Required:
List these molecules in the order in which they first become labeled.
Answer:
GlycineRibulose 1,5-bisphosphate3-phosphoglycerateGlyceraldehyde 3-phosphate.GlucoseSucroseExplanation:
The glycine, among other amino acids, helps to improve chlorophyll production and promotes the process of photosynthesis.
Calvin cycle
During the carbon fixation phase, a CO² molecule combinate with a ribulose 1,5-bisphosphate to form 6-carbonated molecules, which will divide into two 3-phosphoglycerate molecules.
During the reduction phase, NADPH donates its electrons to reduce 3-phosphoglycerate molecules, and turn them into glyceraldehyde 3-phosphate.
During the regeneration phase, a glyceraldehyde 3-phosphate molecule leaves the cycle and goes to the cytosol to form glucose. This step can be done when three CO² enter the cycle and produce six glyceraldehyde 3-phosphate molecules. One of them leaves the cycle to form glucose, while the other five are recycled.
Cytosol:
Once in the cytosol, glyceraldehyde 3-phosphate molecules are used to form glucose and fructose. These two molecules are the monosaccharides that form the sucrose.
Once sucrose is formed, it is transported from the photosynthetic tissues to different parts of the plant by the phloem.
How are traits passed from parent(s) to offspring in sexual vs. asexual reproduction?
Answer:
Heredity
Explanation:
the passing on of physical or mental characteristics genetically from one generation to another
Extra fertilizer in water can cause algae to reproduce and bloom out of control. What type of interaction in the Earth system is this?
Atmosphere-Lithosphere
Hydrosphere-Biosphere
Atmosphere-Biosphere
Hydrosphere-Lithospher
please eaxplain im confused !
The type of interaction in the Earth system between extra fertilizer and algae growth is Hydrosphere-Biosphere.
What are the favorable conditions for algae growth?The favorable conditions for algae growth include minimum sunlight of 10-12 hours a day with an optimum temperature range from 60-80°F.
Fertilizers include the area of biosphere, while water represents the significance of hydrosphere. All the spheres mutually interact with one another for different purposes.
Therefore, the type of interaction in the Earth system between extra fertilizer and algae growth is Hydrosphere-Biosphere.
To learn more about Biosphere, refer to the link:
https://brainly.com/question/12467010
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Answer: Hydrosphere-biosphere
Explanation: I just took the quiz for it and it's correct : )
Photosynthesis and cellular respiration ______?
Answer:
they are opposite 6CO2 + 6H2O → C6H12O6 + 6O2 is the photosynthesis reaction and the reverse is the respiration reaction
Explanation:
A scientist performed an investigation involving a reaction that produced Al,(50), How many sulfur atoms are represented in this formula? A 1 atom B 3 atoms с 7 atoms D 9 atoms
Answer: B, 3 atoms
Explanation: The number of atoms for each element in the formula are calculated by looking at the subscripts and the coefficient. The calculation is given as Al atoms =2x1, S atoms = 3x1 and O atoms = 3x4.
What are the three stop codons?
Answer:
Explanation:
Just doing this to get points see yah later
Answer:
UGA, UAA, and UAG are stop codons.
Explanation:
1. What happens to oppositely charged atoms?
Answer:
they go the opposite direction
Each of the following medical problems involves a malfunction of an organelle or other cell structure. In each case, identify the organelle or structure involved, and indicate whether it is likely to be underactive or overactive.
a. A girl inadvertently consumes cyanide and dies almost immediately because ATP production ceases.
b. A boy is diagnosed with neonatal adrenoleukodystrophy (NALD), which is characterized by an inability of his body to break down very-long-chain fatty acids.
c. A young man learns that he is infertile because his sperm are nonmotile.
d. A young child dies because her cells lack an enzyme that normally breaks down a membrane glycolipid that therefore accumulated in the membranes of her nervous system.
e. A young child is placed on a milk-free diet because the mucosal cells that line his small intestine do not secrete the enzyme necessary to hydrolyze lactose, the disaccharide present in milk.
Answer:
a. mitochondria, underactive
b. peroxisome, underactive
c. flagella, underactive
d. lysosome, underactive
e. Endoplasmic reticulum/Golgi apparatus/transport vesicles, underactive
Explanation:
Cyanide is a toxic compound that inhibits the Cytochrome c Oxidase I (COI) in mitochondria, which is an enzyme known to catalyze the final step in the mitochondrial electron transfer chain. Adrenoleukodystrophy is an X-linked genetic disease caused by a mutation in the ABCD1 gene (ATP-binding cassette, subfamily D, member 1). ABCD1 encodes the adrenoleukodystrophy protein (ALDP), which is involved in the transport of long-chain fatty acids into peroxisomes. Flagella are cellular structures composed of proteins (microtubules) specialized to carry the male's DNA to the egg cell, i.e., they are responsible for sperm motility. Lysosomal storage disorders (LSDs) represent a group of inherited diseases caused by mutations capable of altering lysosome functions. LSDs are especially associated with defective (abnormal) lysosomal enzymes that are unable to degrade macromolecules such as, in this case, a membrane glycolipid. Finally, lactase is an enzyme produced in small intestine cells. Within these cells, the signal sequence of the preprolactase precursor is cleaved in the endoplasmic reticulum (ER). Subsequently, the protein precursor travels to the Golgi complex for processing (i.e., glycosylation), thereby a mature enzyme (lactase) is generated.
List 5 basic structures of bacteria morphology.
Answer:
a nucleoid (DNA), ribosomes, cell membrane, cell wall, and some sort of surface layer,
Explanation:
During photosynthesis, plants use carbon dioxide and water to make sugars and oxygen. Is this a chemical change? Why or why not?
How have human populations used surface currents over time?
Answer:
Changes in land use through time with extrapolations
Explanation:
Population data and projections are from UNDP
where are epithetical tissues found
Answer:
Skin, lining organs, inside mouth, abdominal cavity.
Explanation:
True or false the carrying capacity is the minmum number of individuals in a species that an environment can support
If a solar eclipse occurs when the Moon blocks sunlight from reaching Earth, during what Moon phase would a solar eclipse happen?
Answer:
A solar eclipse occurs when the moon gets between Earth and the sun, and the moon casts a shadow over Earth. A solar eclipse can only take place at the phase of new moon, when the moon passes directly between the sun and Earth and its shadows fall upon Earth's surface
Explanation:
This table is simplified. It is missing a few taxa. What levels are missing and where do they
belong in the table?
A. class, order, and family go between phylum and genus
B. class, family, and order go between kingdom and phylum
C. class goes after kingdom, order goes after phylum, and family goes after genus
D. order goes after kingdom, family and class go after phylum
Answer:
c
Explanation:
What season does the Southern Hemisphere experience when Earth and the Sun are in the positions shown?
fall
spring
summer
winter
Answer:
Explanation:
depends on what time when and where
could be spring ,fall ,or summer
In the homeostasis lab we are using ____________________ as a homeostatic parameter.
Answer:
Body temperature
Explanation:
Homeostasis is the a resistance to change due to the body's attempt to maintain constant and stable internal environment. To maintain the body's overall functioning it is very important that homeostasis is maintained at all levels.
Body temperature can be used as homeostasis parameter in the lab. It is important that that the body tries to maintain a constant temperature.
MULTIPLE CHOICE
If two species have 95% of their DNA in common, what inference can you make about these species?
A
They will look alike.
B
You can't really tell much about the species just base
in DNA
They live in similar environments.
D
They are closely related species.
2 of 10
14
5
6
8
9
Socrative
Answer:
d
Explanation:
Sugar in DNA is called? Sugar in RNA?
what are the different characteristics of a single celled organism.
Answer:
Single-celled organisms are able to carry out all the processes of life without help from other cells
A cross between a plant with red flowers (R = dominant) and a plant with white flowers (r = recessive) yielded 47 plants with red flowers and 51 plants with white flowers. What are the genotypes of the parent plants? Explain.
A. The results are close to a 1:1 ratio of plants with red flowers to plants with white flowers. Therefore, the genotypes of the parents are Rr and rr.
B. The results should yield plants with red flowers and plants with white flowers in a 3:1 ratio due, so the geneotype of each parent is Rr. The number of offspring was not large enough to produce the expected results.
C. The results differ from the predicted values. Therefore, the genotypes of the parents cannot be determined.
D. The results should show a ratio of 3 plants with white flowers to 1 plant with red flowers, so the genotypes of the parent plants are RR and rr.
Answer:
A. The results are close to a 1:1 ratio of plants with red flowers to plants with white flowers. Therefore, the genotypes of the parents are Rr and rr.
Explanation:
I took the test and got it right.
Which vessel takes oxygenated blood from the left ventricle to the rest of the body?
O a. Vena cava
O b. Pulmonary artery
O c. Pulmonary vein
O d. Aorta
Answer:
Aorta
Explanation:
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Answer: 50%
Explanation: makr branlyest plz<3
Two pea plants with purple flowers are crossed. Among the offspring, 63 have purple flowers, and 17 have white flowers. With a chi-square test, compare the observed numbers with a 3:1 ratio and determine if the the difference between observed and expected is statistically significant. Note: Chi-square critical value with 1 degree of freedom is 3.84 with alpha equal to 0.05
Answer:
Chi-square value = 0.6
The difference between the observed individuals and the expected individuals is not statistically significant. There is not enough evidence to reject the null hypothesis.
Explanation:
H₀= Individuals will be equally distributed
H₁ = Individuals will not be equally distributed.
• Chi square= ∑ ((O-E)²/E)
∑ is the sum of the terms
O are the Observed individuals
E are the Expected individuals
• Freedom degrees = 1
• Significance level, 5% = 0.05
• Table value/Critical value = 3.84
The number of observed individuals:
63 have purple flowers, 17 have white flowersTotal number of individuals, N = 80 = 63 + 17
Observed Genotypic frequencies:
F(PF) = 63/80 = 0.79F(pf) = 17/80 = 0.21p² + 2pq + q² = 1
p² + 2pq = F(PF)
0.79 + 0.21 = 1
The expected genotypic frequency:
F (PF)= 0.75
F (pf) = 0.25
The number of expected individuals:
PF= 0.75 x 80 = 60 wf = 0.25 x 80 = 20Chi square = sum (O-E)²/E
PF = (O-E)² /EPF =(63 - 60) ² / 60
PF = 0.15
pf = (O-E)² /Epf= (17 - 20)²/20
pf= 0.45
Chi square= sum ((O-E)²/E) = 0.15 + 0.45 = 0.60
Chi square = 0.6Degrees of freedom = 1 alpha 0.05 Table value/Critical value = 3.840.6 < 3.84 meaning that the difference between the observed individuals and the expected individuals is not statistically significant. There is not enough evidence to reject the null hypothesis. Probably both parentals were heterozygous for the trait.
True or False plants are multicellular prokaryotes with cell walls made of cellulose
Answer:true
Explanation:
Answer:
False.
Explanation:
. . . . ..... . .. . . . .
Which of the following best describes how sedimentary rock forms?
A. Molten rock beneath the surface of earth cools and becomes solid.
B. Layers of sediment becomes compressed overtime to form rock
C. Chemical processes or changes in pressure or temperature change a rock
D. Molten rock reaches the surface and cools to become solid rock.
Answer:
la respuesta B la describe mejor
pls help i need ur guys help pls help me on my science test plsssssssss!
Answer:
1. It can transfer energy through empty space.
Explanation:
Blowfly eggs would most likely be found _____.
near the hands and legs
near the nose and mouth
in the hair and clothes
on the extremities
Answer:
near the nose and mouth
Explanation:
I'm 100% sure this is right
Answer:
near nose and mouth.
Explanation:
got it right!
please help I don't understand
Answer:
Tell me please I help you