Answer:
a. Reduces represor binding.
b. Constitutive expression of the operon.
c. Stronger promoter if it is more similar to the consensus sequence. Weaker promoter if less similar.
Explanation:
The lac operon is an operon required for lactose transport and metabolism in enteric bacteria such as Escherichia coli. It is regulated by glucose and lactose availability and consists of the following structural genes:
Lac z gene: encodes the enzyme β-galactosidase, which catalyzes the hydrolysis reaction of lactose into glucose and galactose.Gene lac y: encodes the protein galactoside permease involved in the transport of lactose into the bacterium.Lac a gene: encodes the enzyme thiogalactoside transferase, which catalyzes the transfer of the acetyl group of acetyl coenzyme A to 6-OH of a thiogalactoside acceptor. This gene is not related to lactose metabolism.Promoter: region of DNA recognized by RNA polymerase for transcription.Operator: region of DNA located between the promoter and the beginning of the structural genes, which is recognized by the repressor protein Lac I.Repressor gene (lac I): encodes the Lac I repressor protein, which recognizes the operator region, where it binds. It prevents the transcription of genes under the control of this promoter but stimulates the binding of RNA polymerase. When the repressor is absent (in the presence of inducer which in this case will be lactose or IPTG), RNA polymerase will begin transcription.The lac operon is under a type of negative regulation, where genes can always be transcribed, except when the Lac I repressor protein is bound to the operon region, for which it has a high affinity. In this case, the promoter of the lac I gene is constitutive, so the Lac I protein is permanently expressed and remains bound in tetramer form to the operon region, preventing the transcription of structural genes.
Since lactose is the inducer of the operon, it is able to bind to the Lac I repressor protein and generate a conformational change that decreases its affinity for the operon region. Thus, the operon region is left free, RNA polymerase can freely transcribe the structural genes and β-galactosidase can degrade lactose to glucose plus galactose. In the absence of lactose, the Lac I repressor protein maintains its high affinity for the operator region, preventing RNA polymerase from transcribing the structural genes. In this way, the system remains closed with consequent energy savings for the bacterium.
As a final clarification, actually the true inducing molecule of the lac operon is called allolactose, an isomer of lactose obtained by a transglycosylation occasionally carried out by β-galactosidase.
a. When there is a mutation in the lac operator that deletes most of the operator, then the repressor Lac I can no longer bind and RNA polymerase will begin transcription.
b. When there is a mutation in the Lac I gene that eliminates the binding of repressor to operator, then this protein can not produce the repression so there would be a constitutive expression of the operon.
c. Since the promoter us a region of DNA recognized by RNA polymerase for transcription, if there is a mutation here it will generate a stronger promoter in the case that this part is similar to a consensus sequence (the most commonly encountered nucleotides found at a certain location). In the case that it is less similar, then it will generate a weaker promoter.
An organism has the following characteristics: cell wall, heterotrophic, unicellular, and prokaryote. What kingdom does it
belong in?
0 Animalia
O Protista
Plantae
O Eubacteria
Answer:
2nd
Explanation:
Which of the following is NOT true about Earth’s systems? A.Together, the the geosphere, hydrosphere, atmosphere, and biosphere work to support life on planet Earth. B. Our atmosphere is the place that holds our oxygen. C. There are many systems, or, parts, that work independently. D. There are many , systems, or parts, of the Earth that work together.
Answer:
d
Explanation:
because each part and system as individual tasks or ways to help the earth
The statement that is not true is that there are many systems, or, parts, that work independently. The correct option is C.
What is Earth's system?The application of systems science to the Earth is known as earth system science. It focuses on interactions and 'feedbacks' in particular.
The five Earth systems interact to create the environments we are familiar with.
Everything in the Earth's system can be classified as either land, water, living things, or air. These four components of the system are referred to as "spheres."
They are the "lithosphere" (land), the "hydrosphere" (water), the "biosphere" (living things), and the "atmosphere" (air).
The geosphere is split up into four subsystems: the lithosphere, hydrosphere, cryosphere, and atmosphere.
Because these subsystems interact with one another and with the biosphere, they work together to influence the climate, trigger geological processes, and influence life on Earth.
Thus, the correct option is C.
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How do helmets protect your head?
a.
By creating a large area to spread out the pressure of a blow to your head.
b.
By focusing the pressure of a blow into a small area.
c.
By creating a vacuum that protects your head.
d.
By creating a pressure gradient that traps energy away from your skull.
Please select the best answer from the choices provided
A
B
C
D
Answer: A
Explanation:
A helmet distributes the impact throughout the entire helmet meaning that the pressure is dispersed within the area
Place the following events in the order they occur by listing their assigned letters in that order. A. Cas9 REC domains binds to the guideRNA B. Cas9 complex binds to dsDNA C. Cas9 complex scans dsDNA for PAM sequence D. Cas9 unwinds dsDNA E. The programmable part of the guideRNA binds to its complementary sequence F. Cas9 cuts both strands to generate a double strand break
Answer: a, b, d, c, e, f
Explanation: The steps of Cas9 DNA recognition and cleavage goes in the following order lettered A, B, D, C, E and F. Cas9 recognizes and binds the sgRNA after which it binds to the double stranded DNA. It then unwinds and scans the dsDNA for its protospacer adjacent motif sequence (PAM) and on recognition the sgRNA binds to its complementary sequence followed by cleavage of the DNA at two points. That is how the double stranded break is created.
Which is an example of a vascular flowering seeded plant?
a peach tree
moss
a fern
a horsetail
which of the following does not take place in the mouth
Answer:
I. sorry but I didn't see options.
Please help! Will mark brainliest.
Answer:
2nd one is the most realistic of what occurs in ecosyystems
I’ll give points + brainalist (:
Your answer would be C. because the rest of potential energy. This one is not stored energy, it's kinetic.
Hope this helps; have a great day!
Answer:
Dang- u got all the easy work but its C..
Explanation:
The light on the top of the aquarium provides what component of an ecosystem?
A biotic
B producers
C energy
D decomposers
Answer:
A is the answer thanks me later
A hydraulic system uses a(n) ____________________ to transmit pressure.
a.
pulley
c.
transducers
b.
fluid
d.
lever
Please select the best answer from the choices provided
A
B
C
D
Answer:
B. fluid
Explanation:
Uses Pascal's law
Answer:
B, it fluid
it's a liquid the moving and confined space under pressure.
What causes acid rain? *
A) Erosion
B) Fertilizers used to increase growth rates of plants
C) Hunting
D) Burning of fossil fuels
Answer:
burning of fossil fuels
Explanation:
acid rain is caused by the air pollution from the burning of fossil fuels
What do organisms use "food" for?
Answer:
Organisms use food to provide the organism's energy
Explanation:
The facts of life :)
Now I'm hungry XD
You should be familiar with the drugstore antibiotic ointment Neosporin (Triple antibiotic ointment), which is often thought of as innocuous. Based on your knowledge of antibiotics from Chapter 12 describe the mode of actions of the three antibiotics found in Neosporin (neomycin, polymyxin, and bacitracin), research their side effects, and postulate on why these three antibiotics were chosen.
Answer: Antibiotics are chemicals which, in low concentrations, can selectively kill or inhibit the growth of most pathogenic bacteria and are not harmful to humans.
Explanation:
Neosporin is a type of antibiotics which is used for the treatment or prevention of mild superficial infections. It consists of three active component, hence the name Triple antibiotic ointment. These active components, their mode of action and side effects include:
--> NEOMYCIN : This is one of the active components of Neosporin which inhibits the protein synthesis of an invading pathogenic bacteria through irreversible binding to the 30 S ribosomal subunit of susceptible bacteria. Their MODE OF ACTION is bactericidal meaning that the effect it has on the protein synthesis inhibits it's growth leading to the death of the bacteria.
SIDE EFFECTS: it can cause irritation, burning, itching, rash redness when applied topically.
--> POLYMYXIN: This is one of the active components of neosporin which attacks the invading pathogenic gram negative bacteria. In its mode of action, is the ability to combine with and disorganise structures of the bacterial cell which are responsible for the maintenance of the osmotic equilibrium of the cell thereby exposing the underlying peptidoglycan layer to lysozyme.
SIDE EFFECTS: Burning, redness, or irritation of the skin may occur.
--> BACITRACIN: This is also one of the active components of Neosporin. In its mode of action, it inhibits bacterial cell wall synthesis. This is achieved by preventing the final dephosphorylation step in the phospholipid carrier cycle, which interferes with the mucopeptide transfer to the growing cell wall.
SIDE EFFECTS: it may cause rash, itching/swelling (especially of the face/tongue/throat).
These three active components of Neosporin are combined to broaden the antibacterial spectrum. This means that at least one of the active components will effectively kill an invading pathogenic bacteria through its unique mode of action.
i will give brainlyest if right
Answer:
d is the answer
Help me somebody is it A,B,C,D
Answer:
D.
Explanation:
The area is very arid and dry. I am sure that they don't have a lot of access to water as is.
Answer:
it would be D
Explanation:
which type of blood vessel normally contains valves to keep the blood flowing in One Direction
a) arteries
b) veins
c) capillaries
B) Viens
The veins have valves to keep the blood pumping out and not coming back in the heart.
What is the most important part in the respiratory system?
The lungs.
The lungs are paired, cone-shaped organs which take up most of the space in our chests, along with the heart. Their role is to take oxygen into the body, which we need for our cells to live and function properly, and to help us get rid of carbon dioxide, which is a waste product.
Please help, I really need help!
Write the name of the natural disaster next the image below. Then indicate whether it is weather-related or geology-related.
Answer:
Earthquake, and geology-related
Explanation:
I think what they are showing are two tectonic plates that shifted along a fault line.
When a filament of algae is illuminated with light that is passed through a prism, different segments of algae are exposed to different wavelengths of light. When aerobic bacteria are present, they congregate in highest concentrations in the areas illuminated by the red and blue light. These data suggest a relationship between which of the following variables?
a) Wavelength of light and rate of aerobic respiration
b) Wavelength of light and amt of heat released
c) Wavelength of light and the rate of photosynthesis
d) Carbon dioxide concentration and the rate of photosynthesis
Answer:
The correct answer is C) wavelength of light and rate of photosynthesis.
Explanation:
The given question is a famous experiment conducted by T W Engelmann which is called the action spectrum experiment. In this experiment when light passes through a prism it splits into its constituent colors splits into violet, indigo, blue, green, yellow, orange and red.
Aerobic bacteria require oxygen for their survival. The green algae produce oxygen during photosynthesis. Engelmann released aerobic bacteria to it. it is found that the bacteria accumulated at the blue and red light because photosynthesis and oxygen release were higher there. So, it establishes the relationship between the wavelength of light and photosynthesis.
what would likely to happen if heavy pressure is applied when using a pumice stone on feet?
Answer:
If you apply too much pressure, you can cause redness and abrasions.
A gardener wanted to know if E-Z fertiliser would be good for his vegetables. He fertilised all his bean plants with E-Z fertiliser but didn’t put any fertiliser on his pepper plants. His beans didn’t do well at all, but he got a good crop of peppers. He concluded that E-Z fertiliser was no good. What are the errors in this experiment? Tick all that apply
A) Not enough subjects
B) Subjects were not similar
C) Conditions were not kept the same
D) The experiment was not reproduced
Answer:
B) Subjects were not similar
The errors in this experiment are: subjects were not similar and conditions were not kept the same. Hence the correct options are B and C.
Subjects were not similar: The gardener used two different types of plants, beans, and peppers, to test the effectiveness of E-Z fertiliser. Beans and peppers have different growth requirements, nutritional needs, and environmental preferences. By using different types of plants as subjects, the experiment introduces variability and makes it difficult to attribute the outcome solely to the fertiliser.
Conditions were not kept the same: The gardener applied E-Z fertiliser to the bean plants but did not provide any fertiliser to the pepper plants. This difference in treatment introduces a significant confounding factor, making it impossible to isolate the effect of the fertiliser on the bean plants' poor performance.
Hence the correct options are B and C.
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An animal has 2 genes: 1 for tail length (T) and 1 for head shape (H). Its genotype is TtHh. What are all of the possible gametes that this organism can make?
Answer:
TH, Th, tH, th
Explanation:
This question involves two genes; one coding for tail length and the other for head shape. According to this question, an organism has the genotype: TtHh.
In accordance to the law of independent assortment, which states that alleles of one gene will segregate independently of one another. The meiotic division of the organism, will occur in such a way that only one allele of each gene is present in any GAMETE.
The possible gametes for the genotype: TtHh are: TH, Th, tH, th
those in agriculture industry need to be particularly mindful of safety because why?
Answer:
Many hazards are present in the farm. If the farmers are not aware of these hazards these may cause injury to their body or may cause diseases and even death. Farmer should always apply appropriate safety measures while working in the farm.
Explanation:
PLZ HELP!!! AG CLASS PLANT SYSTEMS
Which of the following defines viticulture?
A cultivation of stone fruits
B cultivation of apples
C cultivation of grapes
D cultivation of citrus
Answer:
C.Cultivation of grapes
Explanation:
That is correct
Answer:
grapes
Explanation:
no balls
The process of choosing a specific organism to breed based on producing desired traits is called...,
Selective breeding
Natural selection
Natural breeding
Selective evolution
Answer:
selective breeding
Explanation:
It makes the most sense, let me know if i'm wrong.
Which of the following averages for temperature would best reflect an area’s climate?
Select one: Plz help NO LINKS Plz
Average temperature over 30 years.
Average temperature over three days.
Average temperature over three months.
Average temperature over three years.
Explanation:
average temperature over 30 years
hope it may help you
The chart below shows the dates of eclipses in the years 2006 and 2007. What is the
best explanation for the frequency of eclipses?
Date
March 14, 2006
March 29, 2006
September 7, 2006
September 22, 2006
March 3, 2007
March 19, 2007
August 28, 2007
September 11, 2007
Eclipse Type
Lunar, Penumbral
.
Solar, Total
Lunar, Partial
Solar, Annular
Lunar, Total
Solar, Partial
Lunar, Total
Solar, Partial
Where Visible
N. and S. America
S. America, Africa, W. Asia
Europe, Africa, Asia
S. America, Antarctica
Americas, Africa, Europe
Alaska, Asia
Asia, Aus.. Americas
S. America, Antarctica
A. The atmospheric conditions that cause eclipses are only found at certain
locations and times of year.
B. The Moon's orbit is tilted relative to the plane of the Earth's orbit. About every
six months, the Sun, Moon and Earth are aligned enough for a solar and a lunar
eclipse to occur.
C. The Earth and Moon orbit the Sun in opposite directions. When the Moon's
orbit crosses the Earth's orbit, a lunar or solar eclipse will occur.
D. A lunar or a solar eclipse occurs every time the Moon orbits the Earth. The Moon
orbits the Earth four times a year.
Answer:A
Explanation:
The soil in rainforest are_________
Question options:
mediocre
rich in clay
nutrient rich
nutrient poor soil
Answer:
Nutrient poor soil
Explanation:
Because rainforest have very poor infertile.The soil also contains Less organic.
Or for simple answers wet forest bad, dry and healthy forest is good.
The soil in rainforest are nutrient poor soil.
What is Soil?In soil science, a soil type is a taxonomic unit. A distinctive soil type is made up of all soils that have a certain set of well-defined features in common.
The phrase "soil type" refers to the study of soil classification, which is concerned with the orderly classification of soils. Every soil on the planet is a particular soil type.
Minerals, soil organic matter, living organisms, gas, and water are the five components that make up soil. Clay, silt, and sand are the three size classes for soil minerals.
The majority of soil types in hierarchical soil classification schemes are in the higher or intermediate level.
Therefore, The soil in rainforest are nutrient poor soil.
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What process is responsible for producing most of Earth's oxygen?
A.) photosynthesis
B.) respiration
Answer:
Photosynthesis
I hope this helps!
Explanation:
The graph shows how the activity of an enzyme changes at different temperatures. Which
statement best describes what happens to the enzyme when the temperature of the reac-
tion increases to 45 degrees Celsius?
X = optimal temperature
Rate of reaction
20 30 40 50
Temperature / "C
А
The enzyme is used up and the reaction stops.
B
The enzyme begins to decrease the rate of the reaction.
С
The enzyme continues to increase the rate of the reaction.
D
The enzyme changes shape and can no longer speed up the reaction.
Answer: D
Explanation: The enzyme changes shape and can no longer speed up the reaction
-Just did this so it's right lol