A control variable Kept the same to make an experiment a fair test. Thus, option D is correct.
What Is a Control Variable ?
Variables may be controlled directly or indirectly by randomization methods.
A control variable is a type of variable unit which held constant in a research study.
It’s variability does not involve study aims but it is controlled and also show an influencing effect on the study outcomes.
It limits the effect of confounding and other extraneous variables and enhance the internal validity of a study.
In an experiment, the effect of an independent variable on a dependent variable can be investigated, for this control variables will help to understand that the results are caused by manipulated data in experiments.
Thus, option D is correct.
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A biochemist isolates and purifies various molecules needed for DNA replication. When she adds these molecules to DNA, replication occurs, but half of the DNA produced consists of a normal DNA strand paired with numerous segments of DNA a few hundred nucleotides long. What has she probably left out of the mixture
Answer:
DNA ligase
Explanation:
The biochemist must have left out DNA ligase enzyme.
The DNA ligase enzyme is able to catalyze the formation of phosphodiester bonds and as such, capable of joining strands of DNA together to form a single strand.
The numerous DNA segments of a few nucleotides long observed by the biochemist must have been the replicated product of the lagging DNA strand. The lagging strand is replicated discontinuously in short strands because the DNA polymerase enzyme can only elongate primers in 5' to 3' direction. The short segments are known as Okazaki segments and are usually joined together to form a whole strand by the DNA ligase enzyme.
Hence, the missing component is the DNA ligase.
When ______ is released, the subsequent receiving neuron ________ fire because that neurotransmitter is _______.
Answer:
When a neurotransmitter is released, the posterior receptor neuron has the receptor to bind to it because that neurotransmitter is a stimulator of the postsynaptic membrane.
Explanation:
The neurotransmitters that are released from the motor plate, that is, from the postsynaptic membrane to the presynaptic space, are captured by receptors of the postsynaptic membrane, which can be another neuronal structure to transmit an impulse or a muscle to be able to execute the contraction.
I leave you an image that draws up the stimulation of the postsynaptic membrane by means of a neutrotranismor, these are called as: adrenaline, norepinephrine, acetylcholine, etc.
Number 1 is the presynaptic membrane that releases the neurotransmitter (yellow balls), number 2 is the intersynaptic space, 3 is the postsynaptic membrane that in number 4 can be seen to be activated by relating to the neurotransmitter
Streptomyces griseus produces the antibiotic Streptomycin, which inhibits protein synthesis by binding to ribosomes and preventing the binding of fMet‐tRNA. Why isn’t S. griseus harmed by its own antibiotic?
Answer:
See the answer below.
Explanation:
Antibiotic-producing bacteria are generally known to have a mechanism that enables them to be resistant to their own antibiotics. The mechanism that enables them to be resistant to their own antibiotic depends largely on the mode of action of the antibiotic substance.
Some of the popular mechanisms used by bacteria to counter their own antibiotic substance include a mutation in the target gene, production of enzymes that inactivate the antibiotic compounds, or efflux of the compounds.
In the case of Streptomyces griseus, the inactivity of streptomycin has been linked with the production of a phosphatase inhibitor that prevents streptomycin from getting access to the target site. Hence, the organism is not harmed by its own antibiotic.
1. which pair of bacteria can be differentiated by oxidase test?
A. Pseudomonas and E. coli
B. Salmonella and Proteus
C. Proteus and E. coli
D. Shigella and Salmonella
2. Colonies of which color would you expect on HE agar if shigellosis is suspected?
A. Pink
B. Red with black center
C. Red without black center
D. Green with black center
E. Green without black center
3. Colonies of which color would you expect on HE agar if Enterococcus sp. is suspected?
A. Pink
B. Salmon/orange
C. Red with black centers
D. Green with black centers
E. None of the above
Answer:
1. A. Pseudomonas and E. coli
2. B. Red without black center
3. B. Salmon/orange
Explanation:
Pseudomonas is referred to as an oxidase positive bacteria while E. Coli is an oxidase negative bacteria. The use of the oxidase test will be helpful in the differentiation of the two Bacteria according to their oxidase activity/properties.
Colonies of Red without black center color is what is expected on HE agar if shigellosis is suspected.
Colonies of Salmon/Orange color is what is expected on HE agar if Enterococcus sp. is suspected.
Most hurricanes will originate a. near the North Pole. b. in the equatorial region. c. when the water and air are cold. d. below the ocean’s surface currents.
Answer:
The answer is c.
Explanation:
Answer:
c
Explanation:
Deficiency of which material leads to anaemia ?
Answer:
iron
Explanation:
iron is present in red blood cells. Without it the RBC's start to die and are less in number. Which causes anaemia.
A is an agent that causes disease. All are pathogens.
What is the average life span of juvenile upland game birds
Answer:
90 percent
Explanation:
Based on average estimated juvenile and adult survival rate for each species
Your heart rate can be determined by counting the number of times your heart beats per minute. There are several places you can find your pulse—the rhythmic pressure wave of blood in the arteries. The radial pulse can be found by placing two fingers just below the wrist creases at the base of the thumb. Another common place to feel the pulse is the carotid artery in the neck. Place two fingers, index and middle, between the trachea and large neck muscle. Be sure to sit still without talking, and slowly move the fingers together until you can feel the blood flow. In this experiment, you’re collecting data to determine how holding your breath affects your heart rate. Write a hypothesis stating whether your heart rate will increase, decrease, or stay the same after holding your breath for 30 seconds. Also, identify the independent and dependent variables. Hypothesis: _______ Independent variable: _______ Dependent variable: _______
Answer:
The independent variable is the time and the dependent variable is the heart rate.
Explanation:
In this case a study is being performed to determine whether holding one's breath for 30 seconds leads to increasing, decreasing or similar heart rate.
The hypothesis can be defined as follows:
H₀: Holding one's breath does not effect the heart rate.
Hₐ: Holding one's breath does effect the heart rate.
A relationship is to formed between the heart rate and the time for which you are holding your breath.
So, the independent variable is the time and the dependent variable is the heart rate.
Answer:
Lab: Heart Rate
Part A: Identifying Variables
The dependent variable happens as a result of values/changes associated with the independent variable.
Independent variable: number of cigarettes smoked
Dependent variable: risk for lung cancer
Independent variable: number of sharks swimming in a coastal region
Dependent variable: number of shark attacks on humans
Independent variable: amount of milk a person drinks
Dependent variable: the strength of his or her bones
Part B: Heart Rate
Hypothesis: If I hold my breath for 30 seconds, then my heart rate will
(choose 1) increase/decrease.
Independent variable: holding my breath
Dependent variable: heart rate
Part C:
The heart rate decreases because oxygen exchange in the lungs decreases.
This depends on what you chose for heart rate in the hypothesis. If you said the heart rate decreases after holding your breath, and the results showed the heart rate decreased, then the hypothesis is supported. If you said the heart rate decreases after holding your breath, and the results showed the heart rate increased, then you refuted the hypothesis.
Heart rate can change due to an increase or decrease in activity, moving positions such as sitting and standing, and emotions.
Example: Increase in activity—jumping jacks
Hypothesis: If I do five jumping jacks, then my heart rate will increase.
Test hypothesis. You can use the average resting heart rate from the previous experiment. If you do an experiment with an increase in physical activity like jumping jacks, then your data will reflect an increase in heart rate because the body requires more energy, which requires more oxygen, increasing the overall flow of blood in the body.
Support or refute the hypothesis based on the results. The hypothesis is supported if it aligns with the observed results. The hypothesis is refuted if the results don’t match the statement based on the variables.
Testing more than one variable at a time makes it difficult to interpret the results and support or refute the hypothesis. With one variable, the results can be associated with changes to that variable. To get the most reliable data to support or refute a hypothesis, an experiment should be completed several times to see if the results show the same trends.
Explanation:
Lab: Heart Rate
Part A: Identifying Variables
The dependent variable happens as a result of values/changes associated with the independent variable.
Independent variable: number of cigarettes smoked
Dependent variable: risk for lung cancer
Independent variable: number of sharks swimming in a coastal region
Dependent variable: number of shark attacks on humans
Independent variable: amount of milk a person drinks
Dependent variable: the strength of his or her bones
Part B: Heart Rate
Hypothesis: If I hold my breath for 30 seconds, then my heart rate will
(choose 1) increase/decrease.
Independent variable: holding my breath
Dependent variable: heart rate
Part C:
The heart rate decreases because oxygen exchange in the lungs decreases.
This depends on what you chose for heart rate in the hypothesis. If you said the heart rate decreases after holding your breath, and the results showed the heart rate decreased, then the hypothesis is supported. If you said the heart rate decreases after holding your breath, and the results showed the heart rate increased, then you refuted the hypothesis.
Heart rate can change due to an increase or decrease in activity, moving positions such as sitting and standing, and emotions.
Example: Increase in activity—jumping jacks
Hypothesis: If I do five jumping jacks, then my heart rate will increase.
Test hypothesis. You can use the average resting heart rate from the previous experiment. If you do an experiment with an increase in physical activity like jumping jacks, then your data will reflect an increase in heart rate because the body requires more energy, which requires more oxygen, increasing the overall flow of blood in the body.
Support or refute the hypothesis based on the results. The hypothesis is supported if it aligns with the observed results. The hypothesis is refuted if the results don’t match the statement based on the variables.
Testing more than one variable at a time makes it difficult to interpret the results and support or refute the hypothesis. With one variable, the results can be associated with changes to that variable. To get the most reliable data to support or refute a hypothesis, an experiment should be completed several times to see if the results show the same trends.
What challenges would you expect scientists to face when growing plants in space? What challenges will the astronauts have with meeting their own energy needs?
Answer:
the challenges they would expect to see is the plants not having water or air
planted need water to have photosynthesis and since theres no water in space and little to no atmosphere the plants would suffocate
Which statement describes one aspect of an earthquake's magnitude?
It is measured by the Mercalli scale.
It is based on the size of seismic waves.
O It is not usually affected by the amount of fault movement.
It is used to determine damage caused by earthquakes.
Answer:
b. It is based on the size of seismic waves
Explanation:
just did the test
The statement that describes one aspect of an earthquake's magnitude is: "It is based on the size of seismic waves."
What is an earthquake's magnitude?An earthquake's magnitude is a measure of the amount of energy released by the earthquake, and it is determined by measuring the amplitude (height) of the seismic waves generated by the earthquake. The size of the seismic waves is directly related to the amount of energy released by the earthquake, and this is used to calculate the earthquake's magnitude.
The most commonly used scale for measuring earthquake magnitude is the Richter scale, which is based on the amplitude of the largest seismic wave recorded on a seismogram. Other scales, such as the moment magnitude scale, are based on the seismic moment, which takes into account the size of the fault rupture and the amount of slip on the fault.
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In which process does the cell use a vesicle to move molecules into the cell
Answer:
Exocytosis describes the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell.
Don't write Endocytosis !!!
Hope this helps !
Explanation:
Answer:
it's Endocytosis
the other answer is wrong i just did the quiz
Explanation:
Indicate the steps of eukaryotic DNA replication in order, from when a germ cell enters gap 1 (G1) phase to the cell cycle termination.
a. RNA primers are added to provide a 3 end for elongation.
b. RNA is replaced with DNA and lagging strands are joined,
c. Prereplication complex forms at one of many origins of replication.
d. DNA polymerase synthesizes both the leading and lagging strands from 5' to 3'.
e. Active telomerase can extend the lost telomere region.
f. The initiation complex creates an active replication fork as helicase unwinds DNA.
Answer:
Explanation:
1. Prereplication complex forms at one of many origins of replication.
2. The initiation complex creates an active replication fork as helicase unwinds DNA.
3. RNA primers are added to provide a 3 end for elongation.
4. DNA polymerase synthesizes both the leading and lagging strands from 5' to 3'.
5. RNA is replaced with DNA and lagging strands are joined.
6. Active telomerase can extend the lost telomere region.
All these process are the steps involved in the replication of DNA. The replication of DNA involves the biological production of two identical copies of DNA from one original DNA molecule. This is a very important biological process of life as it is involved in the inheritance pattern of life. It is essential in that the 2 daughter cells formed must contain the same sets of chromosome as the original parent.
Identify factors that determine earth’s climates
Answer:
1. distance from the sea
2. ocean currents
3. direction of wind
4. shape of the land /topography
5. distance from the equator
Hope this helps
select the choices that are true statements of the similarities between dna and rna
Answer:
They are both acids
DNA is deoxyribonucleic acid, while RNA is ribonucleic acid.
which proteins serves as a chemical messenger
Answer:
Neuropeptides
Explanation:
They are proteins that function as chemical messengers and are released by neurons. They contain 3 to 36 amino acids.
Hope this helps!!! PLZ MARK BRAINLIEST!!!
Gases are formless fluid that expands to occupancy the space or enclosure they are contained in ? True or false
Answer:
true
Explanation:
Gases are in fact formless liquid that expands to occupancy the space or enclosure they are contained in.
Describe how the end product of digestion of fats and oils is absorbed in humans
Answer:
Hello
In the small intestines bile emulsifies fats while enzymes digest them. The intestinal cells absorb the fats. Long-chain fatty acids form a large lipoprotein structure called a chylomicron that transports fats through the lymph system.
hope this answer is correct
In the small intestines bile emulsifies fats while enzymes digest them. The intestinal cells absorb the fats.
What is the end product of digestion of fats and oils?Lipids (fats and oils) are broken down in the small intestine. The enzyme lipase is responsible for breaking down lipids into fatty acids and glycerol.
How are the end products of fat digestion absorbed?Micelles transport the end products of lipid digestion (free fatty acids and monoglycerides) to the digestive tract lining for absorption.
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name two major vessels that return oxygen-poor blood to the heart. What are the damages for each? Where do they terminate?
Answer:
1. Head, neck, upper limb, thorax - super vena cava - top of the right atrium.
2. Lower limb - inferior vena cava - bottom of the right atrium.
Explanation:
The Heart pumps the oxygen-rich blood to the different parts of the body to Otake oxygen and nutrients to these organs and then takes the oxygen-poor blood returns from the body to the heart.
The two major vessels that return oxygen-poor blood to the heart are 1. superior vena cava (SVC) that drainages Head, neck, upper limb, thorax and terminate at top of the right atrium, and 2. inferior vena cava (IVC), Lower limb and terminate at bottom of the right atrium.
1. Head, neck, upper limb, thorax - super vena cava - top of the right atrium.
2. Lower limb - inferior vena cava - bottom of the right atrium.
What precautionary measure should be taken when storing oil and fats at home?why homogenization and pasteurization of milk are performed at an industrial scale?what are the possible hazards that come across while determining protein content of the meat by kjeldhal appratus?
Answer:
chutiya bhanchod gand mar du teri
Which of the following is a true statement about independent events? They must happen at the same time. They must happen one right after the other. They cannot influence each other. They cannot happen at all.
Answer:
They cannot influence each other.
Explanation:
Independent events have no effect on each other.
Hope it helps.
Question 3 (Multiple Choice Worth 3 points)
(06.04 MC)
A student wants to study the effect of removing thermal energy from a system. Which of the following experiments should the student perform?
Close a circuit by adding a penny and record if the bulb glows.
Close a circuit by adding a nail and record if the bulb glows.
Gradually warm a liquid and record its change in state
Gradually cool a gas and record its change in state
Answer:
Gradually cool a gas and record its change in state.
Explanation:
The experiment is directed towards the removal of thermal energy from a system, so "gradually cool a gas and record its change in state" is the best experiment to use.
Hope it helps.
Which is the best strategy for addressing polluted air?
Reduce the cost of chemicals used in industrial processes.
Study the effects of mold exposure on people who suffer from asthma.
Encourage people to continue burning fossil fuels as they drive vehicles.
Build industrial plants and facilities that release chemicals during processing.
Answer:
Study the effects of mold exposure on people who suffer from asthma.
Explanation:
Air pollution refers to the release of chemical or substances called pollutants into the air that is harmful to human health when inhaled.
One way to address air pollution is to Study the effects of mold exposure on people who suffer from asthma because this is as a result of toxic material inhaled from the air. Mold exposure come from indoor air in buildings with mold growth and the buildings construction consist of some toxic chemicals. Exposure to mold worsen Asthma or lung problems and infants exposed to mold growth have high risk of developing asthma because of the toxic chemicals in the air that trigger asthma.
By studying the effect of mold exposure on people with Asthma can be use to address polluted air because, through the study the detrimental effect will be non and crucial steps will be taken to reduce the content of the polluted air and much care will be taken when constructing buildings by using the correct materials for construction.
Answer:
Study the effects of mold exposure on people who suffer from asthma.
Explanation:
The best strategy for addressing polluted air is by increasing those activities which reduces air pollution and prevent those activities which is responsible for increasing air pollution. People living in moldy environment suffer from asthma disease. When there is mold present in the environment, during inhalation the spores of mold present in the air enter in our body and reach to lung where it causes asthma disease.
Which of the following group of bones in the human body categorized according to shape is correct?
Group of answer choices
skull bones-flat bones
arm and leg bones-short bones
coxal bone- short bone
wrist and ankle -long bones
Answer:
The answer is skull bones-flat bones
Hope this helps you
There is an inherited syndrome in humans in which the cells cannot convert food into energy. Some of the symptoms include muscle weakness and a lack of coordination. Which malfunctioning organelle within the cell can cause this condition? centrioles lysosomes mitochondria ribosomes
150 ml of 54% CaCI2 solution contains how many grams of CaCI2?
Answer:
mass of CaCl₂ = 67.4 g of CaCl₂
Explanation:
A 45% CaCl₂ Solution contains 45 g of solute per 100 mL of solution.
mass concentration = mass of solute (g)/ volume of solution (L)
100 mL of solution = 100 * 1L /1000 = 0.1 L
Mass concentration of solution = 45 g/0.1 L = 450 g/L
Molar concentration of solution = mass concentration / molar mass
molar mass of CaCl₂ = 111 g/mol
molar concentration = 450 g/L / 111 g/mol = 4. 05 mol/L
Number of moles of CaCl₂ present in 150 ml of 4.05 mol/L solution = molar concentration * volume (L)
number of moles of CaCl₂ = 4.05 * 150 * 1 L/1000 = 0.6075 moles
mass of CaCl₂ present in 0.6075 moles = number of moles * molar mass
mass of CaCl₂ = 0.6075 * 111 = 67.4 g of CaCl₂
Conjugated enzymes are a key component of ELISA. To what are these enzymes conjugated, and why is that important?
Answer:
To the antigen so the enzymes are only present when the molecule of interest is also present
To the plastic of the reaction well so the enzymes can concentrate the molecule of interest
To the capture antibody so the enzymes are only present when the molecule of interest is also present
To the detection antibody so the enzymes are only present when the molecule of interest is also present
Explanation:
How does music affect plant growth? To answer this question
what kind of molecule is represented in the diagram?
Answer:
The answer is option B.
TriglycerideHope this helps you
Which of the following example(s) does NOT cause bias in a research study.
A) Measuring body temperature with an oral thermometer in half of subjects and an ear thermometer in others
B) Counting the number of firefighters at your house to predict if it will be destroyed
C) Using a set of standardized questions to measure food intake in children
D) Studying workers to see the effects of a new health care law on unemployed