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.
Which of the following is a true statement?
A. Water breaking apart rocks by freezing and thawing is an example of physical weathering.
B. Water moving pieces of rock from one place to another is an example of chemical weathering.
C. Glaciers carrying rock from one place to another is an example of chemical weathering.
D. Glaciers carrying rock from one place to another is an example of physical weathering.
Answer:
A l think
Explanation: sorry if l´m wrong :(
Answer:
A
Explanation:
I'm not really sure lol
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 are two different characteristics of living things shown by a corn plant?
Answer and Explanation:
The corn plant shows 2 different characters of living by the color of the stock and the corn, and if the corn is big.
This may not be true for all things, so another 2 characteristics may be if the corn stock is growing tall, and that the corn stock does really good when given enough food (soil) and water.
#teamtrees #PAW (Plant And Water)
A blank helps students with social behavioral and emotional well being so they can be successful in school
Answer: School Psychologist
Explanation:
A P E X
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.
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
FAST AS POSSIBLE PLZ!!
Answer: 50%
Explanation: makr branlyest plz<3
What is the phylum and class of a squid
Answer: phylum Mollusca, class Cephalopoda
Explanation:
Which one of the following plates consists of both ocean and continenal crust?
a. South American
b. Pacific
c. Nazca
d. Cocos
Answer:
b
Explanation:
True or False plants are multicellular prokaryotes with cell walls made of cellulose
Answer:true
Explanation:
Answer:
False.
Explanation:
. . . . ..... . .. . . . .
If the boundary between two plates is divergent, it means that the relative motion of the plates at the boundary is ____________.
a. sliding past each other
b. towards each other
c. away from each other
d. none of the above
Answer:
Divergent boundaries occur along spreading centers where plates are moving apart and new crust is created by magma pushing up from the mantle. Picture two giant conveyor belts, facing each other but slowly moving in opposite directions as they transport newly formed oceanic crust away from the ridge crest.
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:
where are epithetical tissues found
Answer:
Skin, lining organs, inside mouth, abdominal cavity.
Explanation:
List 5 basic structures of bacteria morphology.
Answer:
a nucleoid (DNA), ribosomes, cell membrane, cell wall, and some sort of surface layer,
Explanation:
True or False: A greater applied force is not required to move an object with a
greater mass than one with a smaller mass. *
Answer:
false
Explanation:
force=mass x acceleration
more mass means more force
Gallardo and Araneda (1994) studied populations of the rodent, Ctenomys maulinus, before and after an eruption of a volcano in the Andes. Survival was random, and the rodent populations after the eruption were only a small fraction of the size of populations before the eruption. Which of the following is likely to be TRUE of the surviving populations relative to the populations before the eruption?
a) Remaining populations will have reduced genetic diversity
b) Adaptive alleles have decreased in frequency
c) All of the answer choices are possible outcomes in this scenario.
d) Maladaptive alleles have increased in frequency
Answer:
A) Remaining populations will have reduced genetic diversity
Explanation:
A random mating population allows for genetic diversity as each individual have equal chance of been mated to and it allows for perpetuation of frequently occurring genes.
For a small population the frequency of allele is mostly fix with virtually all loci having the same genotype because mating is within small individual and genes whose frequency is few will be drifted out of the population.
Hence, after the eruption due to a small random population diversity will be reduced as diversity occur more in a large random mating population.
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:
In rabbits, an allelic series helps to determine coat color at the color C locus: C (full color), cch(chinchilla; gray color), ch (Himalayan; white with black extremities), and c (albino; all white). The C allele is dominant to all others, cch is dominant to ch and c, ch is dominant to c, and c is recessive to all the other alleles. What types of progeny would you predict from a cross of Cch x cch
Answer:
1 Full color : 1 Himalayan
Explanation:
This question is depicting the multiple allele phenomenon in rabbits where four different alleles are responsible for coat color. The alleles are:
- C codes for full color
- cch codes for chinchilla; gray color
- ch codes for Himalayan; white with black extremities, and
- c codes for albino; all white
However, according to the question, the order of dominance of these alleles is: C > cch > ch > c. Hence, in a cross between Cch x chc, the following gametes will be produced by each parent:
Cch - C and ch
chc - ch and c
Using these gametes in a punnet square (see attached image), the following genotypic proportion of offsprings will be produced;
Cc = full color
Cch = full color
chc = Himalayan (white with black extremities)
chch = Himalayan (white with black extremities)
Hence, full color and Himalayan are the types of progeny that will be predicted from the cross.
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:
Which of the following is most like an earthquake?
A.
Clapping Hands
Bouncing a Ball
B.
Making a Fist
C D
Snapping Fingers
Answer:
B
Explanation:
M A T H
(1)what your 7 year old imagination thinks it looks like
(2) what it really looks like
tell me this aint true lm ao
Answer:
ummmmmm thank u for these 15 pts
Tonicity in cells refers to the concentration of solute in a solution outside the cell relative to______.
Tonicity in cells depends on both the concentration of solute outside the cell and the concentration of solute inside the cell
Tonicity is a concept used in biology that defines the osmotic pressure ( pressure that stops the fluids from entering or leaving cells). This pressure is defined by the concentration of solute (substances dissolved in the liquid) outside and inside the cell.
In this context, the cell is classified as isotonic if there is a balance between the concentration outside and inside; hypertonic if the concentration outside the cell is higher, which causes the cell to shrink of hipotonic if the concentration outside is lower, which causes the cell to swell.
Learn more in: https://brainly.com/question/3568318
Frogs, lizards, and birds all have simular arrangment of bones n thier limbs. BOth thier arms and legs have one bone at the top, two bones at the bottom, little bones and then fingers or toes. What does the similarity o the bone struture suggest about these animals?
A. They have a common ancestar
B. They are comparable in size as adults
C. They evolved at the same time
D. They move in the same way
The similarity of the bone structure suggest about these animals should be that they evolved at the same time
What is bone structure?Bones are considered to be the living tissue that comprise of the own blood vessels, and should be made of the various cell, proteins, minerals, etc. In this it enables them for growing, transformation, and repair via the life.
Since both arm and legs should have one bone at the top, so here we considered the option c should be right.
Learn more about bone here: https://brainly.com/question/11977930
Photosynthesis and cellular respiration ______?
Answer:
they are opposite 6CO2 + 6H2O → C6H12O6 + 6O2 is the photosynthesis reaction and the reverse is the respiration reaction
Explanation:
Look around your school. What are some things that are made of matter
How do you know?
Answer:
Some things around me that are made of matter are desks, lockers, tables, chairs, etc. I know this because everything is made of matter.
Explanation:
Hope This Helps!
(brainliest please, if possible)
please help I don't understand
Answer:
Tell me please I help you
why do cells made in meiosis have less genetic material than other cells?
Answer:
The cellular division in meiosis I is called the reduction division because it results in the reduction of the chromosome number from diploid (cell has two copies of each chromosome, one maternal and one paternal chromosome) to haploid (cell has only one copy of each chromosome, either maternally-derived or paternall.
Explanation:
Unit 4 Cell Transport: What are three major molecules that enter the cell?
Answer:
Water, carbon dioxide, and oxygen can enter the cell.
Explanation:
They can enter the cell because they are small and can use osmosis to enter the cell.
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: