Transcriptional regulation of operon gene expression involves the interaction of molecules with one another and of regulatory molecules with segments of DNA. In this context, define and give an example of each of the following:
a. operator
b. repressor
c. inducer
d. corepressor
e. promoter
f. positive regulation
g. allostery
h. negative regulation
i. attenuation
Answer and explanation:
The operator is a DNA fragment localized between the promoter and structural gene sequences that are able to repress operon transcription. A repressor is a molecule that binds to the operator to inhibit transcription, while an inducer is a molecule that activates transcription by binding either to the repressors or to the activators. A corepressor is a molecule that binds to repressors in order to activate them. A promoter is a DNA sequence localized upstream structural genes which binds to a transcription factor in order to activate operon transcription. Positive regulation is the process by which operon transcription acts as a positive loop, thereby increasing its own transcription, while negative regulation is the process by which operon transcription inhibits its own expression. Allostery refers to the process by which a molecule regulates operon transcription by binding to distal (and therefore non-functional) sites of the operon. Attenuation is a process able to reduce operon transcription and also to block subsequent translation.
A decrease in muscular activity or damage to neurons that attach to skeletal muscle can lead to a reduction in the size of muscle called
Answer:
The correct answer is atrophy
Please i need help !!!☹️
Answer: C. 9
Explanation:
Gestation refers to the time between when a baby is conceived till the baby is delivered. This is why the period of pregnancy is known as the Gestation Period.
During that time and after the fertilized egg implants itself in the uterus, the baby develops and grows until it is ready to be delivered.
The structure this occurs in is the uterus (womb) which is labelled 9 in the structure above.
What two factors must be internally balanced for survival? a) energy and water b) water and materials c) materials and age d) materials & energy
Answer: b is the answer hope i helped :)
If this is correct can I get brainlist pls and thank you
have a blessed day :) d
Explanation:
If one half of a DNA molecule has 8 thymine bases, what else is also true about the DNA molecule? (1 point)
There will be 16 total bases.
O There will be 32 total bases.
There will be 8 adenine bases.
There will be 8 cytosine bases.
The main function of a cell membrane is to allow substances to enter and leave the cell. Which is a correct description of transport through a cell membrane
Answer:
The question is incomplete, below is the completed question:
The main function of a cell membrane is to allow substances to enter and leave the cell. Which is a correct description of transport through a cell membrane ?
a. Diffusion, or passive transport, occurs when molecules diffuse from a lower concentration to a higher concentration.
b. Facilitated transport occurs when proteins that extend through the cell membrane provide a channel through which certain substances can diffuse more rapidly than by passive diffusion.
c. The lipid bilayer opens up and allows the ions or molecules to enter the cell, then closes.
d. Active transport occurs when molecules diffuse from a higher concentration to a lower concentration.
Answer:
b. Facilitated transport occurs when proteins that extend through the cell membrane provide a channel through which certain substances can diffuse more rapidly than by passive diffusion.
Explanation:
Transport through cell membranes can be broadly classified as active transport or passive transport.
Active transport requires energy in the form of ATP for the transportation of substances across the cell membrane.
Option b correctly describes facilitated diffusion, which is a passive-mediated diffusion process, where channels in the cell membrane mainly composed of proteins called transmembrane integral proteins, allow for the movement of certain molecules (mostly polar/hydrophilic) molecules that will not otherwise be transported through simple diffusion because of the hydrophobic nature of the cell membrane.
The other options are wrong because:
a. diffusion or simple transport involves the movement of substances from regions of higher to a lower concentration not lower to higher as suggested here.
c. The lipid bi-layer does not allow ions or hydrophilic molecules because it is hydrophobic in nature, and it is not a channel, so it does not open and closes
d. In active transport, transfer of molecules is from regions of lower to higher concentration and not higher to lower concentration as suggested here.
How can particle interactions explain the properties and behavior of dry ice?
Answer:
Dry ice is the solid form of carbon dioxide (CO2). The particle interaction in dry ice is due to collision between inter-particles which results in agglomeration and shows the properties and behavior of dry ice.
The inter-particle collision in dry ice keeps the high temperature of dry-ice and make it sublimate (solid to gas) at room temperature and normal pressure.
The collision of carbon atoms in dry ice also makes it highly reactive and shows chemical properties of dry ice. When dry ice is added with magnesium, it left black powder, which is carbon
In ______, Gorter and Grendel extract lipids from blood cells. After evaluating them, they propose membranes are made of a ____________.
Answer:
The correct answer would be - 1925, phospholipid bilayer.
Explanation:
Gorter and Grendel performed an experiment in 1925 to extract lipids from blood cell and after extracting the protein they evaluated red blood cell membrane.
They found out that plasma membrane have two lipid layer and these lipids are made of phospholipids. Phospholipids are phosphate group that are attached with the lipid molecule.
Thus, the correct answer would be - 1925, phospholipid bilayer.
Membrane-bounded vesicles that contain enzymes for oxidizing small organic molecules with the formation of hydrogen peroxide are Group of answer choices
Answer:
peroxisomes
Explanation:
The peroxisomes represent one of the organelles of the cell. They are usually small and characterized by membrane-bound vesicles that contain oxidative enzymes.
The enzymes in peroxisomes are involved in the oxidation of organic molecules - a process that leads to the formation of hydrogen peroxide. The later is further converted to water and oxygen by the constituent catalase enzyme of the peroxisomes. Fatty acids are also oxidized in peroxisomes but instead of hydrogen peroxide, acetyl groups that are utilized in other biosynthetic reactions are produced.
During a University of Nevada, Reno blood donation campaign, the frequencies of alleles determining the ABO blood groups were determined to be 0.70 for IO, 0.2 for IA and 0.1 for IB. Assuming random mating, what is the expected frequency of blood type O?
Answer:
The expected frequency of blood type O is 0.49
Explanation: Due to some technical problems, you will find the complete answer and explanation
During the 1800's, what country was a leader of world exploration and placed at the center of most maps?
A. Britain
B. Spain
C. Morocco
D. USA
Answer:
B. Spain
Explanation:
Portugal and Spain are the western European nations that were the primary players in the age of discovery in 18th century. Under the leadership of prince henry the navigator. With the spread of missionary activities, Christianity becomes the world's largest religion. Exploration of the Americas and other nations started from this place.Which of the following statements is true?
An atom consists of protons, electrons, and
neutrons.
An atom consists of protons and neutrons.
An atom consists of electrons bonded to one
another.
An atom consists of protons bonded to one
another.
Answer:
An atom consists of protons, electrons, and neutrons.
Explanation:
The atom of an element is its smallest indivisible particle that retains its chemical properties. Atom is the fundamental and basic unit of matter.
The structure of an atom is made up of a positively charged PROTON, a neutrally charged NEUTRON (both contained in the nucleus) and a negatively charged ELECTRON that surrounds the nucleus. These three particles are called sub-atomic particles. The arrangement and number of these sub-atomic particles determine the properties of the atom.
First Question, A, An atom consists of protons, electrons, and neutrons.
Second Question, B, A nucleus consists of protons and neutrons.
edge
Why do roosters hibernate?
Answer:
The answer is
Explanation:
Roosters hibernate to escape the harsh seasonal variations as it cannot fly to different lands and is a flightless bird.
Hope this helps....
Have a nice day!!!!
A purebred tall pea plant is cross-pollinated with a tall, heterozygous pea plant. Use a Punnett square to determine the probability the offspring inherita
recessive short allele. (I point)
75%
25%
0%
50%
Answer:
50%
Explanation:
because if you use the box method you see that half receive a short alele.
T t
T TT Tt
T TT Tt
Based on the data table below, which number would be the BEST choice for the top number of the scale on the vertical axis of a scatter plot showing this data?
Answer:
D. 70
Explanation:
From the table given, we can easily tell that distance (m) is dependent on time (s). Distance is a dependent variable, while time is an independent variable.
If both variables were to be plotted to show the relationship between them on a scatter plot, the dependent variable is usually plotted on the vertical axis (y-axis), while the independent variable would be plotted on the horizontal axis (x-axis).
Distance would be in the vertical axis, while time would be in the horizontal axis.
Therefore, the BEST choice for the top number of the scale on the vertical axis would certainly be 70, because the highest value for distance (m) on the table of values is 69.
What physical traits were favored in the peppered moth AFTER the Industrial Revolution?
Answer: Their skin color was dark which made the moths blend in. During the Industrial Revolution, the soot from factories caused the trees to become black. The light colored moths became easier to kill because they could not blend into their environment.
Explanation:
I need help with this
Answer:
I know the answer
Explanation:
Yes
Yes
Yes
Which conclusion can be drawn from the experimental observation that a single strand of DNA contains 2100 dA residues and 1800 dT residues?
a. There must have been some loss of material in the extraction because the number of dA and dT residues must be the same.
b. This is a palindromic sequence.
c. There must be 2100 dT and 1800 dA residues on the complementary strand.
d. This must be prokaryotic DNA
e. None of these
Answer:
c. There must be 2100 dT and 1800 dA residues on the complementary strand.
Food microbiologists are scientists who have a background in both microbiology and food science. They focus on how microbes grow, cause disease, and how they can be identified from food. Their work is of importance to the food industry as it relates to the production, preservation, and spoilage of food; and it is of importance to public health and regulatory agencies due to the many diseases that are related to food intake and consumption. Food microbiologists can have varying backgrounds, including training in veterinary medicine. This scenario is about a food microbiologist who works as a food safety inspector who pays a visit to a cheese manufacturing plant and makes some interesting discoveries!
Part A-Understanding the Role of Microbes in Fermentation The Midwest is known for its contribution to the dairy industry Fermented dairy products include milk, yogurt, and cheese. The fermentation process relies on lactic acid bacteria and pasteurization. Fermentation can vary based on what food is being produced, the type of bacteria used to produce lactic acid, and the time and temperature of pasteurization. It is important to the manufacturer to produce a product that won't spoil before it is packaged and sold and that won't result in disease for those who ingest and enjoy it. Julie, a food inspector for a local Michigan health department is going to a nearby cheese plant for a biannual inspection. When she gets there, she will take a tour of the plant and allow the operators to describe what makes their cheese so special. She will use what she understands about fermentation to inquire about their production practices Please sort the following statements as being true or false regarding fermentation and its role in food production. Please recall the role that microorganisms can play in the production of foods.
1. Fermentation allows for sugars to be broken down
2. Starter cutures are for the growth of pathogens or the food such as bread, vegetables, and n food Some grains, fruits, and
3. Fermentation can be used only to Bacteria ane the only have their own microbes that used in the Correct Statements
Answer:
Statements 1 is True.
Fermentation allows for sugars to be broken down
Statements 2 and 3 are false.
Starter cutures are for the growth of pathogens or the food such as bread, vegetables, and n food Some grains, fruits, and
3. Fermentation can be used only to Bacteria ane the only have their own microbes that used in the Correct Statements
Explanation:
In microbiology, fermentation is the process where sugars are broken down by the activities of bacteria to produce alcohol and carbondioxide...therefore statement one is true.
Starter culture are microorganisms use in diary production for producing yoghurt and cheese. They perform fermentation in diary production.
Which of the following is responsible for the conversion of covalently closed circular DNA to supercoiled DNA of the plasmid of: a) endonuclease b) DNA gynase c) topa isomerase d) exonuclease
Answer:
DNA gyrase
Explanation:
DNA gyrase is a bacterial enzyme that plays an important role in catalyzing the negative supercoiling of circular chromosomal DNA. This enzyme belongs to a class of enzymes called topoisomerases which play a major role in transitioning of DNA structure. DNA gyrase conversion of covalently closed circular DNA to supercoiled DNA is ATP-dependent.
The importance of DNA gyrase cannot be overemphasized, because for DNA synthesis to occur, the DNA must have a single-stranded template, hence, DNA gyrase play an important role in unwinding the double-stranded DNA for replication. It has the ability to introduce negative supercoils and relax positive supercoils prior to replication.
The total number of organisms an ecosystem can support is its tolerance range.
true or false
Answer:
false
Explanation:
the total number of organism an ecosystem can support is its trying capacity
Answer:
false
Explanation:
i just took the test.
Give five differences in the alimentary canal of flatworms earthworm and cockroaches
Answer:
Animals are adapted to the complex chain food since when they were no manufactured to the their food system. Without breakdown this complex food chain can not digest without breakdown.
Explanation:
Earthworm alimentary canal:
Earthworm have a segmentation of well developed characteristics of all animals. The alimentary canal of earth worm as well as flatworm consists of buccal cavity, mouth, esophagus, crop, intestines', gizzard, and anus. The digestion occur extracellular that means the digestion occur outside the cells. Cockroach is an omnivores. It ranging from starchy to the sweet things to the paper and clothes etc. It suits its diet. Its alimentary canal consists of Foregut, midgut and the hindgut. Both are different in their structure as well as in their alimentary canal.Match the reactant in gluconeogenesis with the appropriate enzyme.
Enzyme:
a. Fructose dehydrogenase
b. PEP kinase
c. Phosphoglycerase
d. Pyruvate kinase
e. Phosphoglyceromutase
f. Glucose kinase
g. Phosphoglycerokinase
h. Phosphofructokinase
i. Hexokinase
1. glucose
2. fructose-6-phosphate
3. fructose-I , 6-bisphosphate
4. phosphoenolpyruvate
5. 1 , 3-bisphosphoglycerate
6. 3-phosphoglycerate
Answer: a c g e
Explanation:
Which of the following does NOT describe telomerase? A. shortens the telomeres in cancer cells. B. present in embryonic cells. C. It stimulates cell division. D. It is an enzyme.
Answer:
option c is ur ANS mate .......
Is this statement true or false?
A hypothesis is a lucky guess.
Answer:
false!
Explanation: i took the test
The dark bands seen under the microscope in a skeletal muscle fiber are concentrations of actin protein called l-bands . It is true or false.
Answer:
it is false
Explanation:
it appears as light bands under microscope
Answer:
false
Explanation:
because dark band seen under the microscope in a skeletal muscle fiber are concentration of actin protein are known as A bands because they are anisotropic when viewed with polarized light
If bacteria transformed with a recombinant pUC18 plasmid produce white colonies when grown on plates containing ampicillin and Xgal, which of the following is least likely?
a. They produce β-lactamase that provides resistance to ampicillin.
b. They carry a vector that contains a DNA fragment inserted into the multiple cloning site.
c. They produce functional β-galactosidase that cleaves X-gal.
d. They carry a vector with a lacZ gene that has been disrupted and rendered nonfunctional.
e. They carry a vector with the bla gene used as the selectable marker.
Answer:
c. They produce functional β-galactosidase that cleaves X-gal.
Explanation:
β-galactosidase is an enzyme capable of catalyzing the enzymatic hydrolysis of β-galactosides into monosaccharides by hydrolyzing the β-glycosidic bond. On the other hand, X-gal is an analog of lactose composed of galactose, which is widely used in laboratories for the detection of β-galactosidase. In the presence of β-galactosidase, X-gal is hydrolyzed by cleaving its β-glycosidic bond, thereby confirming the presence of β-galactosidase.
the oceanic zone is
Answer:
The oceanic zone is the region of open sea beyond Continental shelf.
Very small changes in the solute concentrations in the various fluid compartments cause water to move from one compartment to another, which alters blood composition and blood pressure. How do the following physiological changes affect blood pressure?
a. Decrease water reabsorption
b. Decrease peripheral resistance
c. Vasodilation
d. Decrease salt intake
e. Decrease blood volume
f. Vasoconstriction
g. Increase peripheral resistance
h. Increase salt intake
i. Increase blood volume
j. Increase water reabsorption
Answer:
a. Decrease water reabsorption : decrease blood pressure.
b. Decrease peripheral resistance : decrease blood pressure
c. Vasodilation : decrease blood pressure
d. Decrease salt intake : decrease blood pressure
e. Decrease blood volume : decrease blood pressure
f. Vasoconstriction : increase blood pressure
g. Increase peripheral resistance: increase blood pressure
h. Increase salt intake: increase blood pressure
i. Increase blood volume : increase blood pressure
j. Increase water reabsorption: increase blood pressure
Explanation:
Total peripheral resistance: This term refers to the resistance offered by the vascular system to the blood flow. This resistance is a result of the friction between the blood and the vessel's walls. In other words, it is the opposition of the vessels to blood flow. The total peripheral resistance is the summary of all the bloody circuit resistances in the body. Those mechanisms that induce vasoconstriction conduce to an increase in total peripheral resistance, while mechanisms that induce vasodilation provoke a decrease in total peripheral resistance. Blood pressure: This term refers to the strength applied by the blood against the vessel walls as it flows. This pressure is determined by the bombed blood strength and the volume as well as by the vessel size and flexibility. Blood pressure changes continuously according to the activity, temperature, diet, emotional state, among others. Salt ingestion causes an increase in plasmatic osmolarity, stimulates thirst, and hence, water ingestion. Sodium retains water, expanding the blood volume and causing an increase in vessel pressure. The antidiuretic hormone, also known as vasopressin hormone, is released by changes in serum osmolarity or blood volume. Its function is to keep homeostasis and make kidneys conserve or keep water by concentrating urine and by reducing its volume. By these actions, the antidiuretic hormone stimulates water reabsorption, according to the organism´s needs. Kidneys control blood pressure in many ways. If the pressure is elevated, kidneys produce the loss of salt and water, normalizing arterial pressure. But if pressure is low, kidneys conserve water.It works because your brain creates images from dots. That’s how you can watch shows that you like a whole lot.
Answer:
The fovea works because your brain creates images from points.
Explanation:
The fovea is located in the center of the eye's retina. It is the structure capable of capturing stitches from what you are viewing and sending those stitches to the brain, which will "stitch" all stitches together and form an image. In summary, the fovea is able to project an image to the brain through pieces of the image, it is formed by cones that allow the transmission of light to the photoreceptors of the eyes.
The fovea works since your brain makes pictures from points.
BrainThe fovea is found within the center of the eye's retina.
It is the structure able of capturing stitches from what you're seeing and sending those fastens to the brain, which can "fasten" all fastens together and frame an picture.
The fovea is able to venture an picture to the brain through pieces of the picture, it is shaped by cones that permit the transmission of light to the photoreceptors of the eyes.
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