Answer:
The correct answer is "mutations in the lac operon or in the promoter region".
Explanation:
The lac operon es a series of genes that are translated and expressed simultaneously, allowing the cell to metabolize lactose when glucose is absent. The E.coli cultures that failed to grow in the presence of only lactose, could have a mutation that affects the lac operon. This mutation could be present in the promoter region or in the lac operon itself, which will result in the absence of lac operon transcription or in the transcription of one or more non active protein, respectively.
The mutation(s) that could explain why the E. coli cultures failed to grow only in the presence of lactose is: mutations in the lac operon or promoter regions.
Recall:
The lactose operon, also called lac operon, is responsible for the transport and metabolism of lactose in E. Coli when glucose is absent.Thus, the possible reason that would make the E. coli cultures not to grow in the presence of only lactose would most like suggest a mutation which might have occurred in the lac operon or promoter region.
Therefore, the mutation(s) that could explain why the E. coli cultures failed to grow only in the presence of lactose is: mutations in the lac operon or promoter regions.
Learn more here:
https://brainly.com/question/23074324
During which phase of the cell cycle do chromatids form?
maggots feed on dead and decaying organisms for energy. what are maggots
Answer:
Decomposers, or as they're alternatively known, detritovores.
Explanation:
Their job is to break down decaying/dead organic matter to recycle it into the soil for plants (mainly). Fungi and bacteria make up the vast majority of decomposers.
molecular genetics experiment: In what way do the percentages of yellow leaves vary between dishes on Day 2? How do you account for this difference? Compare the percentage of yellow seedlings in dish 2 on day 2 with the percentage on day 4. What is the difference? What experimental variable accounts for this difference? How can you account for the difference between the seedlings in dish 1? Is the yellow color genetically or environmentally controlled? How can environmental factors affect inheritance? (Use human height as an example.)
Answer:
See below
Explanation:
There were yellow seedlings in Dish #1 during the light phase and also during the dark in Dish #2. The difference in these results is likely due to the period of exposure to light.
There are more number of yellow seedlings on Day 4. This is probably because of being kept in the dark for a long period of time. Light intensity is the experimental variable that accounts for this difference in appearance.
The yellow color is being environmentally controlled since the parent phenotype was wildtype in this experiment. The environment has an effect on which genes are expressed in the organism, which in turn influences the phenotype observed.
The women has had two miscarriages. What is the chance that she could have a normal child? a. The chance of a normal child is approximately one in four; however, all of the normal children will be translocation carriers.b. The chance of a normal child is approximately one in two; however, all of the normal children will be translocation carriers.c. The chance of a normal child is approximately one in four; however, half of the normal children will be translocation carriers.d. The chance of a normal child is approximately one in two; however, half of the normal children will be translocation carriers
Which is NOT a characteristic of the
climax community?
a) it had a well-drained spatial structure
b) it has a wide variety of species
c) it has an unbalanced ecosystem
d) it has complex food chains
in humans unattached earlobes are dominant over attached earlobes. which could be the genotybe for someone with attached earlobs/Answer/a is Ee/b is e/c is ee/D is E
Answer:
C. ee
Explanation:
attached earlobes isn't the dominant trait, if it isn't dominant then it'll have lower case letters to represent it
Answer:
C
Explanation
hopes this helps :]
Juan conducted an experiment and asked Catherine to replicate it. Juan’s values are 16, 15, 15, 16, and 15. Catherine’s values are 16, 14, 16, 15, and 15.
Answer:
i think inexact
Explanation:
Answer:
c
Explanation:
i took the exam i promise
answer the questions above
Answer:
1. Herbivores are plant eating animals.
2. Goat and sheep
3. Humans and monkey
4. It usually begins with a producer.
5. Lion and tiger
6. The function of the lateral line is to pick up vibrations from the water.
7. To make it slippery so as to escape from enemies.
8. A predator is an animal which depends on other animals for food.
9. Enamel
10. Incisors
11. 32 teeth
12. Molars
13. Pulp cavity
14. Canine
15. 3 incisors
Hope this helps.
When analyzing a cross involving two traits, each trait is analyzed separately, and then the frequencies of each are combined to yield the observed phenotypic ratios. Group of answer choices
Answer:
The correct answer is "True".
Explanation:
The missing options of this question are "true" or "false" and in this case the correct answer is "true". According to the laws of inheritance established by Charles Darwin, the certain traits of species can be analyzed and studied by using crossing experiments. These experiments are performed first by analyzing the traits of each individual separately and second by observing the frequencies of each are combined to yield the observed phenotypic ratios. Different approaches are used to study the frequencies of each allele, and the most widely used is the punnet square approach.
Where does most of the phosphorus cycle take place?
2. Where does cellular respiration take places in the cell?
Answer:
Explanation:mitochondria
The enzymatic reactions of cellular respiration begin in the cytoplasm, but most of the reactions occur in the mitochondria. Cellular respiration occurs in the double-membrane organelle called the mitochondrion. The folds in the inner membrane are called cristae.
Answer:
IT TAKES PLACE IN THE CYTOPLASM BUT MOST OF THE REACTIONS TAKE PLACE IN THE MITOCHONDRIA
Explanation:
Cellular respiration occurs in the double-membrane organelle called the mitochondrion
HOPE IT HELPS
Jack has just returned from the hospital where Jack's father is recovering from a heart attack. The doctors told Jack that his dad's atherosclerosis is very serious. Jack and his wife, Melanie, are worried about Jack's father and also are starting to think about Jack's risk of also having heart disease in his lifetime. He sets up an appointment at his doctor's office and has his blood lipid levels evaluated for the first time. Let's see if you can answer some of the questions that Jack and Melanie have. Which risk factor does Jack have no control over?a. Obesityb. Geneticsc. Stressd. Atherogenic diete. Jack can change all of these risk factors.
The correct answer is B. Genetics
Explanation:
In health, a risk factor is a variable that can make a patient more likely to develop a disease or condition. Additionally, some of these factors can be controlled or changed by the patient, while others cannot be modified. Factors that can be controlled include stress, diet, weight, alcohol intake, and habits. This does not apply to factors such as age or genetics, for example, in the case of genetics, this is determined by the genes of each parent when a human being is formed, and therefore there is not any way to change this; although factors such as diet, stress, or smoking affect the expression of mutations in genes. Thus, the risk factor Jack has no control over is genetics.
Calculate the rate of photosynthesis (mm/hr) for Elodea if when measuring net photosynthesis, the water level moved up 7mm from the initial level in 10 min, and when measuring cellular respiration it took 15 minutes for the water level to move down 1 mm.
Answer:
With 6 we should multiply gross photosynthesis (as we were measuring gross photosynthesis for 10 min).
Explanation:
According to this question:-
Net photosynthesis- 3mm/20min- 1.5mm/10min
Cellular respiration- 1mm/15min- 0.66mm/10min
Gross photosynthesis = Net photosynthesis + Cellular respiration = 1.5+0.66 = 2.16 (mm/10min)
Rate of photosynthesis = (gross photosynthesis)6 = 2.16 *6 = 12.96 mm/hr
As we gage the photosynthesis rate in hr.
The process of photosynthesis is commonly written as 6CO2 + 6H2O → C6H12O6 + 6O2.
With 6 we should always multiply gross photosynthesis (as we were measuring gross photosynthesis for 10 min).
This means that the reactants, six CO2 molecules, and 6 water molecules, are converted by light energy captured by chlorophyll (implied by the arrow) into a sugar molecule and 6 oxygen molecules, the products.
According to this question:-
Net photosynthesis- 3mm/20min- 1.5mm/10min Cellular respiration- 1mm/15min- 0.66mm/10min
Gross photosynthesis = Net photosynthesis + respiration = 1.5+0.66 = 2.16 (mm/10min)
Rate of photosynthesis = (gross photosynthesis)6 = 2.16 *6 = 12.96 mm/hr
As we gauge the photosynthesis rate in hr.
Therefore, the correct calculation of photosynthesis is 6=2.16=12.96mm/hr.
Learn more about the photosynthesis calculation:
https://brainly.com/question/12372353
How are lysosomes pro-nuclear dense bodies?
Answer:i hope this answers ur question
Explanation:
The process of succession is necessary to maintain and establish stable communities. T or F
Answer: True it is necessary
Answer:
True
Explanation:
The largest taxon and consists of all the other taxis called
Answer:
Domain
Explanation:
Comparison of glycogen synthesis and breakdown in muscle and liver reveals: A. Stimulation of glycogen breakdown in both tissues by epinephrine leads to enhanced glucose uptake by liver cells and enhanced glucose export from muscle cells. B. Stimulation of glycogen synthesis by insulin in both tissues leads to glycogenolysis in both liver and muscle. C. Inhibition of glycogen synthesis in both tissues by epinephrine leads to glycogenolysis in both liver and muscle. D. Stimulation of glycogen synthesis by insulin in both tissues is accompanied by decreased glycogenolysis. E. Epinephrine stimulates glycogen uptake in liver and breakdown in muscle.
Answer:
The correct options are C and D:
C- The inhibition of glycogen synthesis in both tissues by epinephrine leads to glycogenolysis in both the liver and muscle.
D- The stimulation of glycogen synthesis by insulin in both tissues is accompanied by a decrease in glycogenolysis.
Explanation:
The presence of epinephrine causes the glycogen reserve that is present in the liver and muscle to enter the glycogenolysis stage, that is, the chemical structures of glycogen are broken and simplified in energy coins (ATP) so that the activity muscle contract against stimulation of the adrenergic nervous system.
The adrenergic nervous system is one that promotes physical activity, physiological stress, flight from danger, and other activities, is also known as the sympathetic system and is where epinephrine or adrenaline predominates as a neurotransmitter.
The liver and muscle are the only possible organs to reserve glycogen in a limited way, once its reserve limits are exceeded it will begin to deposit in the form of adipose tissue, glycogenogenesis or formation of glycogen as reserve is promoted by insulin and the system parasympathetic nerve, visceversa to what we explained above with the sympathetic nervous system and epinephrine, since the latter break the glycogen reserves releasing glucose into the blood for muscle contraction.
From the following list, correctly identify the reason(s) that might explain a decrease in Vmax due to a suboptimal pH during an enzyme assay.
a. Protonation of the substrate
b. Deprotonation of the amino acids in the enzyme’s active site
c. Denaturation of the protein’s tertiary structure
d. Decrease in the rate of substrate collisions with the enzyme’s active site
e. Change in the entropy of the reaction
f. Increase in the molar extinction coefficient (e) of the product
Answer:
The correct answer is -
a. Protonation of the substrate.
b. Deprotonation of the amino acids in the enzyme active site.
c. Change in tertiary structure in extreme conditions.
Explanation:
During an enzyme assay, suboptimal pH is changed and affect the Vmax to decrease and this could take place due to various reasons such as-
A) protonation of the substrate - Upon protonating or adding a proton or hydrogen cation to a substrate atom, the mass and the charge of the species each increase by one unit which make a conjugate acid.
B) Deprotonation of the amino acids in the enzyme’s active site -Changing the pH will affect the charges on the amino acid molecules.
C) Denaturation of the protein’s tertiary structure- Tertiary structure of the protein is basically a backbone of peptide chain with one or more secondary domains of proteins that increasing the pH or decreasing the pH get denature.
Thus, the correct answer is : option A, B, C.
Suppose a plant breeder wants to isolate mutants in tomatoes that are defective in DNA repair. However, this breeder does not have the expertise or equipment to study enzymes in DNA repair systems.
Which methods would best allow the breeder to identify tomato plants that are deficient in DNA repair?
A) Expose putative DNA repair mutant plants to ionizing radiation L and see if they survive less well than wild-type plants.
B) Measure the amount of post-translational processing that occurs in the putative DNA repair mutant plants. Measure the somatic mutation rates for the putative DNA repair mutant plants.
C) Expose the putative DNA repair mutant plants to a deaminating agent and select those that have a decreased mutation rate.
D) Measure the germ line spontaneous and induced mutation rates for the putative DNA repair mutant plants.
The provided question has marked options incorrectely the correct order as follows:
A) Expose putative DNA repair mutant plants to ionizing radiation L and see if they survive less well than wild-type plants.
B) Measure the amount of post-translational processing that occurs in the putative DNA repair mutant plants.
C) Measure the somatic mutation rates for the putative DNA repair mutant plants.
D) Expose the putative DNA repair mutant plants to a deaminating agent and select those that have a decreased mutation rate.
E) Measure the germline spontaneous and induced mutation rates for the putative DNA repair mutant plants.
Answer:
The correct answer is: A), C) and E)
Explanation:
The breeder wants to isolate the mutants in tomatoes that are defective in DNA repair, to identify such plants breeder should follow these methods as they will allow best to identifying the defective tomatoes-
Measure the somatic mutation rates for the putative DNA repair mutant plants.
Measure the germline spontaneous and induced mutation rates for the putative DNA repair mutant plants.
Expose putative DNA repair mutant plants to ionizing radiation L and see if they survive less well than wild-type plants. This will allow the breeder to see and analyze the ability of DNA repair in tomatoes
1. D Value is determined as a
A. Removing of microorganisms by washing
B. Concentration of disinfectant required to reduce microbial population 10 times
C. Time required to kill 10% of microbial population
D. Time frame in which microbial population of 5,600,000 cells would decrease to 560,000 cells
E. None of the above
2. The betadine or alcohol swab before blood donation is an example of A. Pasteurization
B. Disinfection
C. Sterilization
D. Preservation
E. None of the above
Answer:
1. D. Time frame in which microbial population of 5,600,000 cells would decrease to 560,000 cells.
2. Disinfection
Explanation:
Hope it helps .
In 1668 Francesco Redi did a series of experiments on spontaneous generation. He began by putting similar pieces of meat into eight identical jars. Four jars were left open to the air, and four were sealed. He then did the same experiment with one variation: instead of sealing four of the jars completely, he covered them with gauze (the gauze will exclude the flies while allowing the meat to be exposed to air). In both experiments, he monitored the jars and recorded whether or not maggots (young flies) appeared in the meat.
Refer to the paragraph on Redi's experiments. In both experiments, fies appeared in all of the open jars and only in the open jars. Which one of the following statements is correct?
A. The experiment was inconclusive because it did not nun long enough
B. The experiment supports the hypothesis that spontaneous generation occurs in rotting meat.
C. The expertment supports the hwpothesis that maggots arise only from eggs laid by adult flhes
D. The experiment was inconclusive because Redi used only one kind of meat
Answer:
The experiment supports the hypothesis that maggots arise only from eggs laid by adult flies; that is only from reproduction and development.
Explanation:
The objective of this experimental set up by Francesco Radi was to demonstrate the concept of spontaneous generation. He concluded that, Maggots are not spontaneous generated from rotten meats, rather they are products of eggs laid by houseflies who visited the rotten meat to lay eggs. The maggots (larva) are products of complete metamorphosis, from egg to larva to pupa and adult. This is an indication that, new organisms are not formed form spontaneously, but are products of well-defined process of reproduction and development which in this case is a complete metamorphosis.
Based on this premise he concluded that, if maggots were products of laid eggs, then they should appear only when rotten meat is exposed to open air.However,if they are f products of spontaneous generation they should appear irrespective of the meat exposure to air or not.
g If a pair of sister chromatids fail to separate during anaphase II (meiosis II), what will be the chromosome number of the four resulting gametes with respect to the normal haploid number (n)
Answer:
The result will be two gametes with a normal haploid number (n), one gamete containing an extra chromosome (n + 1) and one gamete missing one chromosome (n − 1).
Explanation:
Nondisjunction is caused by the failure in the mechanism of separation of homologous chromosomes or sister chromatids during meiosis and/or mitosis. The failure in the separation of sister chromatids during meiosis II is referred to as 'secondary nondisjunction' and it produces two daughter cells with abnormal chromosome numbers.
The fusion of one gamete containing an extra chromosome (n + 1) with a normal (n) gamete will lead to trisomy (2n + 1), while the fusion of one gamete missing one chromosome (n - 1) with a normal gamete will lead to monosomy (2n-1).
Hurry please!!!
Which statement accurately describes long-term environmental changes?
Long-term environmental changes cause changes in genetic makeup.
Long-term environmental changes happen suddenly with little warning,
Long-term environmental changes occur in hundreds of years.
Long-term environmental changes immediately affect organisms in the environment
Answer:
A. or #1 -- Long-term environmental changes cause changes in genetic makeup
Explanation:
Answer: A
Explanation:
At the neuromuscular junction, _______ must enter the synaptic end bulb to stimulate the release of ____________, which binds to ligand gates so ________ can enter the muscle fiber.
Answer:
At the neuromuscular junction, calcium must enter the synaptic end bulb to stimulate the release of acetylcholine, which binds to ligand gates so sodium ions can enter the muscle fiber.
Explanation:
Skeletal fiber contractions are based on different physiological and biochemical phenomena that happen in every cell. These phenomena are due to stimulation produced by somatic motor neurons, which axons get in contact with muscle fibers through a neuromuscular synapse. In rest, attraction strengths between myosin and actin filaments are inhibited by the tropomyosin. When an action potential is originated in the central nervous system, it travels to the somatic motor neuron membrane: the muscle fiber, and activates the calcium channels releasing it in the neuron. Calcium makes vesicles to fuse with the membrane and release the neurotransmitter named acetylcholine (Ach) into the synaptic space in the juncture. Then, Ach binds to its receptors on the skeletal muscle fiber. This causes the ion channels to open, and positively charged sodium ions cross the membrane to get into the muscle fiber (sarcoplasm) and potassium get out. The difference in charges caused by the migration of sodium and potassium makes the muscle fiber membrane to become more positively charged (depolarized). The action potential caused by this depolarization enters the t-tubules depolarizing the inner portion of the muscle fiber. This activates calcium channels in the T tubules membrane, that make the calcium be released into the sarcolemma. At this point, tropomyosin is obstructing binding sites for myosin on the thin filament. When calcium binds to the troponin C, the troponin T alters the tropomyosin by moving it and then unblocks the binding sites. Myosin binds to the uncovered actin-binding sites, and while doing it ATP is transformed into ADP and inorganic phosphate. Z-bands are then pulled toward each other, thus shortening the sarcomere and the I-band, and producing muscle fiber contraction.
Which of the following is a known limiting factor for good nutrition
Answer:
seems you forgot the "followings" but here are some known limiting factors
Explanation:
Exercise,Physiology, Mindset, Nutrition and Genetics.
The allosteric effector molecule 2,3-BPG facilitates transfer of oxygen between maternal and fetal blood in the placenta. Which of the following correctly describes the role of BPG in this process?
a. Fetal hemoglobin binds oxygen better than maternal hemoglobin because BPG is unable to cross the placenta into fetal blood, causing more fetal hemoglobin to be in the R state.
b. Fetal hemoglobin binds oxygen better than maternal hemoglobin because BPG is present at similar levels in fetal and maternal blood, but it binds poorly to fetal hemoglobin, causing more fetal hemoglobin to be in the R state.
c. Fetal hemoglobin binds oxygen better than maternal hemoglobin because BPG is present at similar levels in fetal and maternal blood, but it binds poorly to fetal hemoglobin, causing more fetal hemoglobin to be in the T state.
d. Fetal hemoglobin releases oxygen better than maternal hemoglobin because BPG is present at similar levels in fetal and maternal blood, but it binds more effectively to fetal hemoglobin causing more fetal hemoglobin to be in the T state.
Answer:
b. Fetal hemoglobin binds oxygen better than maternal hemoglobin because BPG is present at similar levels in fetal and maternal blood, but it binds poorly to fetal hemoglobin, causing more fetal hemoglobin to be in the R state.
Explanation:
BPG is a chemical compound which is found in red blood cells. It is known for decreasing the affinity of hemoglobin with oxygen and thus helps in unloading oxygen from hemoglobin.
Owing to the structural difference, fetal hemoglobin binds to BPG with less affinity as compared to maternal hemoglobin thus it shifts the oxyhemoglobin curve to the left i.e. causes fetal hemoglobin to be in the R state. Due to this, fetal hemoglobin can carry up to 30% more oxygen as compared to maternal hemoglobin. As a result of this, oxygen is readily transferred to fetal blood when maternal blood enters placenta which restricts hypoxia in fetus.
Please describe the regulation of the blood glucose 6 hours after a meal?
Please include all relevant organs, hormones, and actions.
Answer:
Find the description below in the explanation section
Explanation:
The body system regulates the blood sugar level via the hand-in-hand working of insulin and glucagon hormones, both produced by the Pancreas. After a meal, the food undergoes digestion and is broken down into glucose, which is absorbed into the bloodstream. Insulin hormone is released by the pancreas (stimulated by a negative feedback) when the sugar level of the blood increases. This secretion of insulin causes cells to absorb glucose as source of energy, while liver and muscle cells store some of the excess blood glucose as GLYCOGEN.
However, after about 6 hours of taking the meal, the blood sugar (glucose) level must have decreased. This triggers the secretion of Glucagon hormone by the Pancreas. Glucagon hormone, acts in an opposite manner as Insulin hormone, by causing the stored GLYCOGEN in the liver and muscle cells to be converted back to Glucose in order for cells to make use of it.
This continuous process occurs and it is how the body regulates the blood glucose levels.
Some present-day bacteria use a system of anaerobic respiration characterized by an electron transport chain analogous to that found in aerobic organisms. Which of the following correctly characterizes the anaerobic electron transport chain?
a. It uses oxygen as a final electron acceptor.
b. It is embedded in the outer mitochondrial membrane rather than the inner mitochondrial membrane.
c. It establishes a proton gradient between the cytoplasm and the extracellular fluid.
d. It establishes a proton gradient between the intermembrane space and the cytoplasm.
e. None of these answer options accurately characterizes the anaerobic electron transport chain.
Answer:
The correct answer would be:
Neither of these response options accurately features the anaerobic electron transport chain.
Explanation:
The anaerobic respiration system vibrated by an electron transport chain is a mechanism that anaerobic bacteria have to maintain their respiration.
This mechanism does not require oxygen in the atmosphere, that is why it is said to be an anaerobic mechanism.
Bacteria do not all need oxygen in the environment to live, some need that oxygen is not exactly present (strict anaerobes) or that it is at low partial pressures (facultative anaerobes).
This mechanism is very characteristic in its location since it is located in the inner membrane of the mitochondria, that is why it will decide to indicate that option as the correct one.
10. How is Soil formed? What is Soil Erosion?
Answer:
soil is formed by weathering of rocks
soil erosion is the removal of the top soil by agents of erosion such as water, wind and ice
Soil is formed by various factors:
The Sun heats up rocks during the day so that they expand. At night, these rocks cool down and contract. Since all parts of the rock do not contract and expand at the same rate, this results in crack formation and huge rocks break up into smaller pieces.Water is another factor for soil formation. Water could get into the cracks in the rocks formed due to uneven heating by the Sun. If this water later freezes, it would cause the cracks to widen. Flowing water wears away even hard rock over long periods of time. Fast flowing water often carries big and small rock particles downstream. These rocks rub against each other and the resultant abrasion causes the rocks to wear into smaller and smaller particles. The water takes these particles along with it and deposits it further down its path. Soil is thus formed in places far away from its parent-rock.Wind also erode rocks down. The wind also sand from one place to the other.Living organisms also influence the formation of soil. The lichens grow on the rock surfaces. It releases certain substances that cause the rock surface to powder down and form a thin layer of soil. Other small particles like moss, are able to grow on this surface now and they cause the rock to break up further. The roots of big trees sometimes go into cracks in the rocks and as the roots grow bigger, the crack is forced bigger.Thus, soil is formed like this.Removal of the topsoil is known as the soil erosion.Hope you could get an idea from here.
Doubt clarification - use comment section.
Second class levers are best described as follows:___________.
A) "The muscle force and resistive force act on opposite sides of the fulcrum, and the effort required to move the load is at a mechanical advantage"
B) "The muscle force and resistive force act on opposite sides of the fulcrum, but the effort required to move the load is at a mechanical disadvantage"
C) "The muscle force and resistive force act on the same side of the fulcrum, with a longer moment arm for the effort than for the load"
D) "The muscle force and resistive force act on the same side of the fulcrum, with a longer moment arm for the load than for the effort"
Answer:
A, B, C, D!
Explanation: