Easy. HISTORY or GEOGRAPHY books of specific areas you want to know more about.
Describe the probable effects on gene expression in the lac operon of each mutation: a. Mutation in the lac operator that deletes most of O1 b. Mutation in the lacI gene that eliminates binding of repressor to operator c. Mutation in the promoter near position
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.
In what way are thermal pollution and eutrophication similar in their impacts on aquatic ecosystems?
A) Both processes are caused by sewage effluent.
B) Both processes occur often in the spring and rarely in the winter.
C) Both processes increase the nutrients that are available in the freshwater ecosystem.
D) Both processes can lead to lowered dissolved oxygen and reduced biodiversity in lakes and rivers.
Answer:
“Eutrophication is an enrichment of water by nutrient salts that causes structural changes to the ecosystem such as: increased production of algae and aquatic plants, depletion of fish species, general deterioration of water quality and other effects that reduce and preclude use”.
Explanation:
Hey mate... Here's your answer...
If 4,000 units of energy are available in the producer level ,about how much would be available to the tertiary consumers?
PLEASE HELP ME!!!!.....
Answer:
ATP
Explanation:
Answer:
The answer is ATP
Explanation:
During cellular respiration, glucose and oxygen are converted into carbon dioxide and water, and the energy is transferred to ATP
What must always be present in order to form a true scientific explanation?
What is the range of the data below?
A box-and-whisker plot. The number line goes from 100 to 125. The whiskers range from 102 to 115, and the box ranges from 109 to 114. A line divides the box at 111.
2
5
12
13
Answer:
13
Explanation:
i did it in edge
Answer:
D. 13
Explanation:
got it right on edg
A greater stability of the biosphere would most likely result from
O A. decreased finite resources
O B. increased deforestation
O C. increased biodiversity
O D. decreased consumer populations
Answer:
C
Explanation:
Increased biodiversity helps diminish reliance on one species
Greater stability of the biosphere would most likely result from increased biodiversity (Option C).
Biodiversity refers to the observable variation in the life forms in a given ecosystem.Biodiversity greatly contributes to maintaining the homeostasis (internal equilibrium) in an ecosystem.In consequence, the loss of biodiversity (often due to human activity) can lead to the collapse of the ecosystem.In conclusion, greater stability of the biosphere would most likely result from increased biodiversity (Option C).
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Approximately 5 percent of the present human genome consists of segmental duplications that have arisen during the past 35 million years. How do you suppose researchers are able to estimate how long it has been since a particular region of a chromosome was duplicated
Answer:
by using molecular clocks which are based on the mutation rates among molecular sequences (e.g., DNA sequences). The mutation rate can be used to estimate the times of divergence between sequences (in this case, between duplicated sequences in the target species and non-duplicated sequences in the most recent common ancestor).
Explanation:
A molecular clock is a technique that uses the mutation rate (μ) to measure the association between evolutionary rate and time. A mutation rate can be used to estimate the time in prehistory when two or more molecular sequences diverged. For example, assuming a generation time of 20 years, a species that has 100 mutations per generation is divided by 20 years to yield a mutation rate equal to 5 mutations per year. In consequence, the times of divergence can be estimated by dividing half of the target genomic region length (in nucleotides) by the mutation rate (t = d/2 ÷ μ).
Which part is circled?
alcohol group
fatty acid
carboxyl group
unsaturated lipid
DAnswer:
Explanation:
give proof and show work and ill give brainliest
Answer:
An outbreak of a disease that infects squirrels in the park.
Explanation:
All the other answer choices would increase the population of squirrels. For the first option, more trees = more habitats = more squirrels to live in. For the second option, less hawks = less predators = more squirrels that will survive. For the third option, heavy rain = more acorns = more food for more squirrels.
Only the last option would limit the growth of a population of squirrels since diseases kill organisms in a population.
In the human AB blood type, allele A and allele B are both expressed. So if an individual inherits allele A from their mother and allele B from their father, they have blood type AB. What type of inheritance does this example illustrate?
I believe it is called "codominance"
PLEASE HELP DUE IN LIKE AN HOUR PLSSS
Answer:
how are they making you do that in an hour
Explanation:
Which statement describes the phospholipid bilayer that makes up a cell membrane?
Answer:
Phospholipids arrange in two layers. Fatty acid chains from each layer are "sandwiched" in the middle away from water in and out of the cell.
Explanation:
Both species of garter snakes prey on the California newt, Taricha torosa, a small amphibian that produces a potent neurotoxin (TTX) in its skin. However, neither species of garter snake is affected by TTX. The resistance to TTX is associated with mutations in the SCN4A gene. Which of the following best supports a claim that
a. TTX resistance arose independently in T.
b. atratus and T.
c. sirtalis
Complete question:
Both species of garter snakes prey on the California newt. Taricha torso, small amphibian that produces a potent neurotoxin (TTX) in its skin. However, neither species of garter snake is affected by TTX. The resistance to TTX is associated with mutations in the SCN4A gene. which of the following best supports a claim that TTX resistance arose independently in T. atratus and T. sirtalis?
A. The stomach contents in fossils of both species include the remains of food items that contains TTX.
B. Both species of snakes possess the SCN4A gene.
C. The two species of snakes have different genetic mutations in the SCN4A gene.
D. T. atratus and T. sirtalis are sister species that share many of the same morphological features.
Answer:
C. The two species of snakes have different genetic mutations in the SCN4A gene.
Explanation:
These are two different species that feed on the same amphibian species and that developed resistance to TTX. Resistance to the toxic is associated with mutations in the SCN4A gene. So probably both species by separated developed different mutations in the gene that led them to be resistant to the toxin.
Supporting the fact that natural selection is not random, both species might have become resistant to TTX through different mutations in the same gene. Both species are feeding on the California newt that produces neurotoxin in the skin. Animals that feed on this amphibian need to be resistant to the toxin to avoid death and keep preying. TTX might be acting as a modeling pressure that led snakes to develop resistance to the toxin, favoring the same phenotype but independently.
A. The stomach contents in fossils of both species include the remains of food items that contain TTX. → Food items with TTX in the stomachs do not mean that species were resistant to the toxin. And if they were, it does not mean that species developed the resistance independently or not.
B. Both species of snakes possess the SCN4A gene. → The fact that both species have the gene does not mean that they have mutations in the gene
C. The two species of snakes have different genetic mutations in the SCN4A gene. → That both species have different mutations in the same gene means that they evolved independently from each other. They suffered different mutations in the same gene that led them to express the same resistance phenotype.
D. T. atratus and T. sirtalis are sister species that share many of the same morphological features. → Morphological features do not necessarily reflect molecular features. The fact that they are similar sister species does not say anything about the SCN4A gene.
The condition that best supports this experiment is the two species of snakes have different genetic mutations in the gene described above.
What do you mean by Mutations?Mutations may be defined as sudden, stable, and inheritable changes in the genetic material of an organism.
Both species of snake have different mutations in the same gene means that they evolved independently from each other. They undergo different mutations in the same gene that led them to express the same resistance phenotype.
Therefore, the condition that best supports this experiment is the two species of snakes have different genetic mutations in the gene described above.
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6. Which organisms in the food web shown
below compete for the same food source in
this environment?
Answer:
1) Snakes and Hawks
2) Frogs and Snakes
Explanation:
1) The snakes and the hawks both eat frogs.
2) The frogs and snakes both eat grasshoppers.
Using the figure, match the following
The muscle fiber (cell) is indicated by
Label A
Label B
Label C
Label D
Answer:
Hope it helps
Explanation:
The label A represents mitochondria.
The mitochondria are also called the powerhouse of the cell which converts glucose to energy-rich molecules of ATP.
Label B represents the nucleus.
The nucleus contains the genetic material or DNA, RNA, nucleolus, chromatin fibers, and proteins. It contains the chromosomes which control the hereditary characteristics.
Label C represents the lysosome.
Lysosomes contain digestive juices which break down large cell parts and large molecules and help in intracellular digestion.
Label D represents rough endoplasmic reticulum having ribosomes.
The rough endoplasmic reticulum provides a surface for protein synthesis. It is also used to transport cellular contents from one cell to another.
_______ are thought to have been present before vertebrates.
Answer:
invertebrates i guess
Explanation:
hope it helped!!!
1.) Chordates
2.) phylogeny
3.) most recent common ancestor
4.) derived
5.) homologous
6.) analogous
7.) opposable
8.) prehensile tails
9.) Lucy
10.) neanderthalensis
11.) Using comparative anatomy, scientists identify similarities and differences in the anatomy of different species. Scientists would search for homologous structures, analogous structures, and vestigial structures to provide clues as they construct a cladogram.
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Which of the following are NOT used by cells for energy storage?
a.
fats
c.
carbohydrates
b.
oils
d.
nucleic acids
Please select the best answer from the choices provided
A
B
C
D
pls help only this q Explain how losing one part of this food chain will unbalance the whole ecosystem.
Answer: The extinction of dinosaurs will lead to increase in the prey which they used to consume before extinction.
Explanation:
Many years ago the dinosaurs used to dominate on earth as large mammals. They were plant eater herbivores and animal consumer carnivores. After the extinction of dinosaurs the ecological balance got disturbed. Flowering plants dominated the earth. The large and massive non-bird dinosaurs died but the bird like dinosaurs survived and they passed their traits to some lineages of modern birds.
human disruption of the carbon cycle has been implicated in..?
Answer:
D. Climate change
Explanation:
The carbon cycle is disrupted by several activities of man which includes burning if fossil fuels anong others. These leads to accumulation of huge amounts of carbon dioxide in the atmosphere which leads to global warming. The resultant effects of global warming is what one of the major cause of climate change.
Therefore, human disruption of the carbon cycle can be said to have been implicated in climate change.
Im having trouble with this
How does overpopulation harm a species?
biodiversity is highest near the
A: equator
B: oceans
C: temperate zone
D: the poles
Give an example of physical evidence used to organize Earth’s history on the geologic time scale.
Answer:
The Earth is 4.6 billion years old. Some examples of events listed on the geologic time scale include the first appearance of plant life on Earth, the first appearance of animals on Earth, the formation of Earth's mountains, and the extinction of the dinosaurs.
Explanation:
please mark this answer as brainliest
Bird species from temperate regions must cope with relatively short breeding seasons. A study examined the relationship between blood testosterone level (ng/ml) and the duration of the egg-laying period (months) in temperate bird species. The scatterplot below displays this relationship, after taking the logarithm of each variable. A plausible value for the correlation between the logarithm of egg-laying duration and the logarithm of testosterone level is
Answer:
The answer is "-0.4".
Explanation:
In that situation, the value of the possible correlations between the egg-laying logarithm as well as the testosterone level logarithm is equal to 4 It value is equal to the percentage 4=-0.4.
When all of the populations live together in the same area, what is it called?
A. A community
B. A niche
C. An environment
D. An eco system
Answer:
When all of the populations live together in the same area, it is called:
A community
Why? Because a community occurs when multiple people are together, and the prefix com means "together".
By the way, I put in D on Edge, and it was wrong.When all type of the populaton lived together in the similar area so we called them as the community.
What is community?The population means the group of individual that are interbreeded with respect to the same species that should be isolated from the other group
while on the other hand, the community means the group or two or more various species that have the similar kind of geographical area.
Therefore, the option A is correct.
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Drag each label to the correct location on the image.
Classify the following actions as ethical or unethical actions.
Answer:
Ethical:
-Giving a sick cow antibiotics.
-Euthanizing a horse suffering from an incurable disease and pain.
Unethical:
-Disclosing medical records of a patient without consent from the pet owner.
-Concealing information about a genetic defect from a dog breader.
Explanation:
In the field of veterinary medicine, ethics is a set of moral norms and mandates of conduct for veterinarians in which the welfare of the animal and the prevention of its suffering are prioritized, at the same time as the search for clear and detailed information regarding the use of animals for different purposes, be they commercial or otherwise. Thus, any activity that prevents the suffering of an animal will be considered ethical, at the same time that any activity that produces immediate or future suffering to an animal will be considered unethical.
Why are vestigial structures not removed by natural selection ?
Answer:
because natural selection only acts on traits that impact reproductive success.
What do we call the area of Earth,
from the top of the highest mountain
to the bottom of the ocean, in which
all life exists?
A. atmosphere
B. life bubble
C. biosphere