Answer:
-Alphaproteobacteria
-Betaproteobacteria
Explanation:
Proteobacteria are gram-negative bacteria that can either be pathogenic or free-living parasitic in nature. Several classes fall under the category of proteobacteria, and two of them are alphaproteobacteria and beta proteobacteria. Both Alphaproteobacteria and Betaproteobacteriaare are the ones that play an important role in nitrogen fixation and since according to the question the research is focused studying the role of proteobacteria in the global nitrogen cycle, it is wise to choose these two bacterial classes.Final answer:
For studying the role of proteobacteria in the global nitrogen cycle, Beta Proteobacteria is the correct option to focus on, as they play a significant role in this biochemical process.
Explanation:
If you are setting up your own lab to study the role of proteobacteria in the global nitrogen cycle, focusing on specific classes within the proteobacteria phylum is crucial. Based on the information provided, Beta Proteobacteria play a significant role in the nitrogen cycle. These bacteria are diverse and include species fundamentally involved in nitrogen transformations. Therefore, your research should include studying Beta Proteobacteria.
While other classes of proteobacteria, such as Delta and Epsilon, have notable roles in other environmental or health-related aspects, they are not primarily noted for their involvement in the nitrogen cycle in the provided context. Thus, the correct option for your research focus should be:
Beta Proteobacteria
What is a biofilm? A layer of sugars that persist even after bacteria have been killed by antibiotics A group of bacteria that accumulate in layers and secrete an protective extracellular material Free-floating bacteria that move through the blood to other sites A bacterial cell that secretes an extensive network of fibers around its cell wall
Answer:
A group of bacteria that accumulate in layers and secrete an protective extracellular material.
Explanation:
The biofilm is a natural way how the bacteria get together to survive in an ecosystem or in another living thing. They build little by little this kind of building with different layers of bacteria that secrets a polymer, this protection polymer could be useful to protect the colony or to be attach to another cell or to a tissue. In medicine and in veterinarian studies is interesting because can be useful to create a film to protect some injuries.
Answer: A group of bacteria that accumulate in layers and secrete an protective extracellular material
Explanation:
Biofilm comprises any spectrum of microorganisms, including pathogens in which cells stick to each other and to a surface, so they become adherent cells. These cells become embedded within an extracellular matrix that is composed of extracellular polymeric substances (polysaccharides, lipids, proteins and DNA) which surrounds and protects cells. For this reason, bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics.
On a NASA mission that was looking for life on Mars, soil samples were taken and measured for the breakdown of nutrients and the production of carbon dioxide gas. Which characteristic of life would this test measure?
A scientist wants to perform a test that will indicate whether a nucleic acid sample is composed of RNA or DNA. Testing for the presence of which of the following is most appropriate in this situation?A) phosphate
B) nitrogen
C) guanine
D) uracil
E) thymine
Final answer:
To determine if a nucleic acid sample is RNA or DNA, testing for the presence of uracil is most appropriate, as it only occurs in RNA, not DNA.
Explanation:
A scientist who wants to perform a test to determine whether a nucleic acid sample is composed of RNA or DNA should test for the presence of the nitrogenous base uracil. DNA contains the nitrogenous bases adenine (A), cytosine (C), guanine (G), and thymine (T), while RNA contains adenine, cytosine, guanine, and uracil but not thymine. The presence of the uracil would indicate that the sample is RNA, and the absence would indicate that the sample is likely DNA. Similarly, if thymine is present, the nucleic acid is more likely to be the DNA as RNA does not contain thymine.
The use of microbial products in a commercial setting has become very popular due to the environmentally friendly aspects of this process. The products so-produced, are readily degraded, non-toxic, and typically result from__________
Answer:
Typically result from enzymatic metabolism.
Explanation:
Many microorganisms are used in various branches in the commercial sector, from manufacturing food products to promoting cleanliness in a contaminated environment. These microorganisms promote a cheap action and without degrading nature, because naturally, through their enzymatic metabolism can create biological products of great economic value for humanity.
A researcher studied two groups of fruit flies
Population A was kept in a 0.5 L container
Population B was kept in a 1 L container
3. The independent variable in the controlled experiment was the
a. number of flies
b. number of groups studied
c. number of days
d. size of the containers
Answer:
D
Explanation:
An independent variable is variable in an experiment that is not affected by another variable and is often used to influence the other variables, which are dependent variables. In this case the size of the container is the independent variable because its changes affect the behavior of the fruit flies. The behavior of the fruit flies is the dependent variable. The number of flies, that is kept constant, is the controlled variable.
Question 6
A weak base ______ in solution.
A)dissociates completely
B)does not dissociate completely
C)does not dissociate
D)none of these
Answer:
a
Explanation:
its th eopposite of acid and a weak acid will not dissociate
hope this helps :)
The weak base B) does not dissociate completely.
Explanation:Bases are the substance which produces [tex]OH^-[/tex] ions when dissolved in aqueous solution or when they are treated with water. The pH of bases remains above 7. They react with salt and cause neutralization a process through which salts are formed.
Based upon the dissociation rate, they are classified as strong base or week base. The base which gets completely dissolved in aqueous solution or water, it is called as strong base, whereas the base which gets partially dissociates or does not dissociate completely when treated with water or aqueous solution are called weak base.
Measuring the height of a plant is an example of _____ data
Qualitative
Experimental
Quantitative
Measuring the height of a plant is an example of quantitative data
Answer: Option C
Explanation:
When there is an experiment performed there are 2 types of data that can be recorded one is a qualitative data and quantitative data. Qualitative data is a type of data that describes the quality of the product formed whereas the quantitative data is a data that quantitative the numerical values that we get through the experiment. A quantitative data is more authentic than a qualitative data as it provides figures for comparison.
Which of the following statements about lysosomes is false?
a. Lysosomes help to digest worn-out or damaged organelles.
b. Lysosomes synthesize proteins from the recycled amino acids.
c. Lysosomes fuse with food vacuoles to expose nutrients to lysosomal enzymes.
d. Lysosomes destroy harmful bacteria engulfed by white blood cells.
Answer:
The correct answer is option b. "Lysosomes synthesize proteins from the recycled amino acids".
Explanation:
Lysosomes are organelles of eukaryotic cells which main function is the digestion and removal of waste by the action of degradative enzymes. Is false to affirm that lysosomes synthesize proteins from the recycled amino acids, on the contrary, lysosome function is to degrade proteins not synthesize them.
The false statement about lysosomes is that they synthesize proteins from the recycled amino acids. Lysosomes are involved in digestion and disposal of cellular waste and harmful bacteria but protein synthesis is not a function of lysosomes.
Explanation:Among the statements provided, the one that is false is: b. Lysosomes synthesize proteins from the recycled amino acids. Lysosomes are cellular organelles that are primarily involved in the digestion and disposal of cellular waste products, worn-out organelles, and harmful bacteria. However, the synthesis of proteins is not a function of lysosomes, this process is carried out by the ribosomes in the cell.
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Correctly order the steps involved in cellular immunity:
a) The Tc recognizes the infected host cell
b) The Tc interacts with epitope presented by MHC-I on the dendritic cell
c) The Tc secretes perforin and granzyme, causing apoptosis
d) The helper T cell activates the Tc cell
Answer: A, B, C, D
Explanation: 1. The Tc recognizes the infected host cell
2. The Tc interacts with epitope presented by MHC-I on the dendritic cell
3. The Tc secretes perforin and granzyme, causing apoptosis
4. The helper T cell activates the Tc cell
Cell-mediated immunity is mediated by T lymphocytes. They originate in the bone marrow and mature in the thymus. T cell interact with other cells via its T cell receptor. (TCR). It can only interact with antigenic peptides bound to the Class I MHC molecules on the surface of antigen presenting cells. (APC).
When a TCR of a naïve T cell interacts with and antigen which presents the Class I MHC molecules it gets activated and undergoes differentiation and proliferation which is also known as clonal selection.
There exist two types of T cells
1. Effector or Helper T cells
2. Memory T cells
Cell-mediated responses has both innate and specific immune components. Among the common innate components is the antigen-presenting cell (APC), which interacts with T helper cells to initiate the immune response. After the recognition of the antigen takes places the Tc interacts with epitope presented by MHC-I on the dendritic cell
In addition to granzymes and perforin, T cells are able to produce granulyson and lymphotoxin.
The correct order of steps involved in cellular immunity is as follows:
The dendritic cell phagocytoses the pathogen and processes it.The dendritic cell presents pathogen-derived antigens on its surface using MHC class I molecules.The infected host cell is recognized by the cytotoxic T cell (Tc).The Tc interacts with the epitope presented by MHC-I on the dendritic cell.The helper T cell (Th) recognizes the same antigen presented by the dendritic cell.The activated helper T cell secretes cytokines that activate the Tc cell.Cellular immunity, also known as cell-mediated immunity, is a branch of the immune system that involves the activation and response of specific immune cells to defend the body against pathogens, such as viruses, bacteria, fungi, and parasites. It is one of the two major components of the adaptive immune system, along with humoral immunity.
Cellular immunity primarily relies on the action of specialized white blood cells called lymphocytes. The main types of lymphocytes involved in cellular immunity are T cells (or T lymphocytes) and natural killer (NK) cells.
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Differences in female and male reproductive biology have led to different mating strategies for men and women. This is an example of what developmental perspective?
Answer: Evolutionary
Explanation:
Evolution of the male and female reproductive organs is necessary for the advancement of mating strategies that range from simple to complex living beings. This is a kind of adaptation those which have phenotypic characteristics favourable to attract the mates will reproduce the offspring. These traits will be passed on to the progeny and evolution of the species will take place.
One pathway that produces ATP starts with glucose. When glucose enters a cell, it is broken down via successive steps. Along the way, some ATP is produced directly. With regard to the breakdown of glucose, this is an example of__________ pathways.
Answer:
catabolic pathways.
Explanation:
The degradation of complex substances into simpler ones are catabolic processes. They release the energy stored in their bonds and are able to transfer the energy to the adenosine triphosphate (ATP) molecule.
The breakdown of glucose involves a lot of successive steps releasing all the energy contained in their bonds.
It is a clear example of a catabolic pathway.
which of the following characteristics is shared by all organisms?
A. all organisms are composed of two cells
B. all organisms can smell and taste
C. all organisms have cells that contain DNA
All organisms have cells that contain DNA is the characteristic shared by all organisms.
Deoxyribonucleic acid (DNA) is a molecule present in all living beings contains the genetic information that living beings use to function, acting as a guide with the instructions for the construction of the rest of the components of cells.
DNA is a biopolymer that houses the data for the synthesis of proteins and that makes up the genetic material that cells have.
This nucleic acid also enables data to be transmitted through inheritance.
Its "units" are called bases and are made up of four main molecules: adenosine, thymidine, guanidine, and cytosine.
With specific combinations of these four units, all the specific proteins of each life form are encoded in DNA.
Therefore, we can conclude that DNA is the most important molecule present in all living beings since it is the one that stores hereditary information and also the information for the correct functioning of all living organisms.
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What usually happens to the accuracy of an estimate of population size as the number of fish caught increases? A. The estimate is usually more accurate. B. The estimate is usually less accurate. C. The accuracy of the estimate will not change. D. The estimate is most accurate when the number of fish caught is 50% of the total population.
Answer:
You would expect the accuracy to increase as you caught more fish since you are getting a bigger more precise population sample.
Your answer is A
Answer:
A. The estimate is usually more accurate.
Explanation:
When you are dealing with statistics the larger the sample you are taking, the most accurate and closer to the real population you get, in this case if you keep catching fishes to make samples from, you can get a more accurate estimate of the characteristics of the population. The least samples you take, the further from the actual population you get.
Which statement best describes the role of DNA ? It transmits genetic information to the next generation. It speeds up chemical reactions inside of cells. It directly forms proteins. It provides a form of energy for cells.
Answer:
It transmits genetic information to the next generation
Explanation:
DNA stores information on how the cell should be made and ‘run’. This is why it is critical that its integrity is well preserved. Otherwise, mutations on DNA can be lethal to the cell. In higher cells, DNA is protected in the nucleolus. To pass down the genetic information, DNA is replicated by DNA polymerases and then during cell division, either copy of the pair goes to each of the two daughter cells.
Answer:
transmits genetic info to next gen
Explanation:
taking the test
QUESTION 6
A weak base ______ in solution
A)dissociates completely
B)does not dissociate completely
C)does not dissociate
D)none of these
Answer:
does not dissociate completely
Explanation:
does not dissociate completely. Strong base dissociates completely, weak base only does it partially and it is according to its Kb (equilibrium constant)
The weak base B) does not dissociate completely.
Explanation:Bases are the substance which produces [tex]\bold{OH^-}[/tex] ions when dissolved in aqueous solution or when they are treated with water. The pH of bases remains above 7. They react with salt and cause neutralization a process through which salts are formed.
Based upon the dissociation rate, they are classified as strong base or week base. The base which gets completely dissolved in aqueous solution or water, it is called as strong base, whereas the base which gets partially dissociates or does not dissociate completely when treated with water or aqueous solution are called weak base.
What is another important difference between mitosis and meiosis?
A. Mitosis can only occur in cells that are diploid (or have higher ploidy).
B. Meiosis can only occur in cells that are diploid (or have higher ploidy).
C. Mitosis can occur in haploid as well as diploid cells.
D. Both B and C above are important differences.
E. None of the above describes a difference between mitosis and meiosis.
Answer:
d.both b and c
Explanation:
meiosis can occur in diploid cells because the chromosomes duplicate once, and through two successive divisions, four haploid cells are produced, each with half the chromosome number of the parental cell and also Meiosis occurs only in sexually reproducing organisms.
Mitosis is not restricted to diploid cells.Because Mitosis means Equational division i. e the number of chromosome will remain same after division. So it can occur in both diploid as well as in haploid cells.
Phylogenetic trees can be most accurately constructed using A. DNA B. Traits in common between organisms due to homology C. Linnaean classification D. combination of DNA and traits in common between organisms due to homology E. combination of Linnaean classification and DNA
Answer: Option A
Explanation:
A phylogenetic tree is an imaginary diagram which is used to represent the evolutionary relationship among organism.
It is a form of hypothesis not a definite fact, that the branching of trees reflect how the organism have evolved from the common ancestors.
It shows how two organisms are related to one another and it shows that two organism that have similar characters share more recent common ancestors.
Answer:
E) Combination of Linnean classification and DNA
Explanation:
The Linnean classification gives us a map and a orientation on where to go in the branches of families. The DNA give us the relationships between relatives
Some orchids grow high on trees so that they can get enough light for photosynthesis. The trees are unaffected by the presence of the orchids. The relationship between the orchids and the trees is an example of __________.
Answer: Commensalism (Symbiotic relationship)
Explanation:
Commensalism is a type of symbiotic relationship in which one species gets benefits while the other species remain unaffected.
Orchids are epiphytes which grows on the inner branches of trees of rainforest that helps in taking nutrients directly from the air around them and sometimes from the decaying organic matter of their host tree. Epiphytic orchids stores water in their stems and compensate in dry periods. Trees having rough barks that holds humus and water in it's crack supports orchids better than other trees with smooth barks.
One of the hormones is GIP (glucose-dependent insulin trophic peptide), which stimulates the secretion of insulin. It is secreted by cells of the duodenum in response to the presence of glucose. Its secretion and action on insulin production is an example of a:a. homeostatic positive feedback mechanism amplifying the response to glucose ingestion.b. homeostatic negative feedback mechanism, keeping a system near a set point.c. homeostatic negative feedback mechanism changing the set point.d. this response is not homeostatic.
Answer:
The correct answer is option- b. homeostatic negative feedback mechanism, keeping a system near a set point.
Explanation:
Homeostasis is a resistance system of the body that balances the body according to the change to maintain equilibrium in the system or body. It can take place with negative or positive feedback.
The negative feedback mechanism is the action that opposes to cue or stimulus presented by the system. For example, GIP is the hormones that help in the increase in insulin release and suppress the release of glucagon. It also prevents the blood sugar hike by slow emptying of gastric.
Thus, the correct answer is - B. homeostatic negative feedback mechanism, keeping a system near a set point.
The opposable big toea) is present in nonhuman primates but not humans, because humans lost this feature. b) is only found in Old World primates. c) is present in all primates. d) is present in nonhuman primates but not humans, because primates evolved this feature.
Answer:
a) is present in honhuman primates but not humans, because humans lost this feature.
Explanation:
The opposable big toe is a trait that helps to primates to climb trees easily. Humans' ancestors started to walk in two legs, this created a needing for better stability, so a fixed toe became to evolve to allow our bipedal locomotion.
Therefore, options b and c are wrong. Option d is wrong too because it implies that the group "primates" is newer than "humans", and in fact, "humans" is part of the group "primates", so this is not the correct answer.
The opposable big toe is present in all primates, including humans. Its functionality has been crucial for evolution allowing efficient gripping in many tasks. Though less opposable in humans due to evolution favoring walking, it is not entirely lost.
Explanation:The opposable big toe is a characteristic found in all primates, including humans. The opposable toe has been crucial in primate evolution, allowing for efficient gripping and manipulation of objects, which has been instrumental in tasks such as foraging for food and navigating arboreal environments.
The toe of humans is not as opposable as those of non-human primates. As humans evolved to walk on two legs (bipedalism), the toe evolved to provide balance and propulsion during walking and running, reducing its opposability to an extent, but not losing it entirely.
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Problems in using common names to universally identify living things include:
Names mean different things to different people.
Foreign names may not be understood.
Many names may exist for the same organism.
There may be no common name for an organism.
Common names lack sufficient precision.
Enough common names are not available to name every living thing.
multiple choice.
Answer:
Names mean different things to different people.
Explanation:
Language barriers could prevent something from being understood
As well as this, a word that might be normal in one language could have a completely different meaning in another language
Answer:
There may be no common name for an organism.
Names mean different things to different people.
Foreign names may not be understood.
Many names may exist for the same organism.
if fossil fuels are constantly being formed why is it important for humans to find alternate sources of energy?
Answer:
Fossil Fuels Take Millions of Years to FormExplanation:
The fossil fuels that we are using today were created way back when dinosaurs still roamed the earth. Fossil are constantly being replenished. However, they take a very long time to form. They form way too slowly to replenish at the rate that we are using them. Also, even if they did replenish, they have so badly polluted our planet to the point where many species hang in the balance that it is paramount to find alternate sources of energy before the planet is destroyed to the point where it can no longer sustain life.
PLEASE MARK BRAINLIEST
Which of the following is NOT an example of an epigenetic phenomenon provided by Dr. Carey on evidence that genetic identity does not lead to identical phenotypes in organisms?
a) kittens turn into cats
b) Maggots turn into flies
c) Some reptiles' genders are determined by the temperature of their nests
d) Humans have 200 different types of cells that develop from 1 DNA code
In humans, every cell in the body contains the same DNA code, which consists of the entire set of genetic instructions. The answer is d) Humans have 200 different types of cells that develop from 1 DNA code.
During development, cells undergo a process called epigenetic regulation, which involves modifications that control gene expression without altering the DNA sequence itself. Epigenetic modifications include chemical modifications to DNA, such as methylation, as well as modifications to histone proteins that package DNA.
Dr. Carey provided evidence that genetic identity does not lead to identical phenotypes in organisms through various examples of epigenetic phenomena. However, the fact that humans have 200 different types of cells that develop from 1 DNA code is not an example of an epigenetic phenomenon. It is a result of cellular differentiation and specialization during development, where different cells express different genes and perform specific functions, but it does not involve epigenetic modifications.
Therefore, the answer is d) Humans have 200 different types of cells that develop from 1 DNA code.
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Sensory and motor tracts within the spinal cord
a. are separated into sensory tracts on the right and motor tracts on the left side of the spinal cord
b. have names that indicate the location of the initiation and termination of the nerve impulses
c. they conduct are located in the gray matter
d. all of these choices are correct
Answer:
b. have names that indicate the location of the initiation and termination of the nerve impulses
Explanation:
The sensory and motor tracts are sets of nerve fibers that run inside the central nervous system; more precisely within the spinal cord and they are named according to the path their fibers have, that is, we will call them indicating from where they begin to where they arrive.
For example, the spinothalamic tract is a sensory tract that carries the sense of touch and pressure from the spinal cord to the thalamus.
On the other hand, corticospinal tracts are linked to isolated and specialized voluntary movements (especially from the distal part of the limbs) and descend from the cerebral cortex to the spinal cord.
As for the other options, I can say that they are incorrect because the tracts do not differ to the right and left of the cord in sensory and motor. Also, the tracts are located in the white substance not in the gray.
Sensory and motor tracts are both present in the spinal cord but are not segmented by the sides. These tracts are named for their initiation and termination points, and are found in the spinal cord's white matter, not the grey.
Explanation:In the spinal cord, both sensory and motor tracts coexist, providing a pathway for nerve signals. Contrary to option a, they are not separated into sensory tracts on the right and motor tracts on the left. Instead, sensory tracts carry signals from peripheral body parts to the brain while motor tracts transmit signals from the brain to the muscles or glands. Option b is correct, as these tracts are often named based on their point of origin and endpoint. On the other hand, the tracts are found in the white matter of the spinal cord, not the grey matter as option c suggests. Thus, not all options provided are correct.
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What is the basic function of the outer ear?
a. to filter out high-intensity sound waves that can be harmful
b. to amplify low-intensity sounds to detectable levels
c. to protect the hair cells
d. to concentrate and funnel sound waves to the eardrum
e. to filter out low-intensity sound waves that can be harmful.
Answer: Option D.
Explanation:
Outer ear is the external part of ear called pinna with a helical shape.
Pinna helps in collecting sound waves and guide them to the eardrum.
The pinna helps in assisting the difference in pressure inside and outside the ear. Pinna function sin resisting the high pressure of sound waves inside the ear and makes the smoother sound to transmit which passes into the auditory canal.
Hence, the correct option is D.
The basic function of the outer ear is to concentrate and funnel sound waves to the eardrum.
Explanation:The basic function of the outer ear is to concentrate and funnel sound waves to the eardrum. It acts like a funnel, capturing and directing sound waves towards the ear canal and eardrum. This helps in collecting and transmitting sound efficiently. The shape of the outer ear helps in determining the direction of sound as well.
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Since bacillus megaterium are non-motile, they may not be able to avoid harmful toxins in the environment.
b. megaterium is known to have endospores; why would endospore formation be advantageous for this bacterium? choose the best answer(s).
Answer:
B, C, & D
Explanation:
Just like any other organism, bacteria too also need to survive in their environment. When the environment become unfavorable for growth and development, they shift from a vegetative state to a dormant state. They do this through formation of endospores that are highly resistant to extreme stress. This is especially significant for bacteria that have no motility. Bacteria that have flagella can move into a new environment.
Final answer:
Endospore formation is crucial for Bacillus megaterium, providing a survival mechanism against extreme conditions. These endospores ensure the bacterium's durability through periods of high temperature, chemicals, and nutrient deprivation, enabling it to survive and later thrive once conditions improve.
Explanation:
Endospore formation is highly advantageous for Bacillus megaterium, despite being non-motile and unable to avoid harmful toxins. These endospores enable the bacterium to survive extreme environmental conditions that are not conducive to its vegetative state. Since B. megaterium can encounter such conditions due to its non-motile nature, having a mechanism to enter a dormant state ensures its species’ survival over long periods. This includes resistance to high temperatures, chemicals, and even lack of nutrients.
Endospores are essentially a survival mechanism, allowing B. megaterium to withstand unfavorable conditions until the environment becomes conducive for growth again. These endospores are incredibly resistant, capable of surviving for millions of years and bringing the bacterium back to life under the right conditions. Furthermore, their ability to resist antibiotics and most disinfectants adds another layer of survivability against attempts to eradicate them in clinical settings.
Given this context, the formation of endospores is crucial for B. megaterium to persist through periods of environmental stress, thereby ensuring the continuity of their species even when immediate growth conditions are not available. This capability is particularly valuable considering the harmful toxins and adverse conditions the bacteria may encounter due to its lack of mobility.
Close examination of an organ reveals a lining of multiple layers of cells. The layers are avascular and regenerate well. One surface of the cells is open to the internal cavity of the organ and protection and absorption are its functions. This tissue is probably:
Answer:
Epithelial Tissue
Explanation:
The epithelial tissue can be classified according to the amount of layers, such as simple epithelium (formed by a single cell layer) or stratified epithelium (formed by more than one cell layer).
In addition, this tissue is avascular, in other words, it has no proper blood supply. Its nutrient transport usually occurs by diffusion through connective tissue.
The epithelium layers are able to regenerate quickly and easily when destroyed. Being a coating tissue, its cells have high healing power.
The epithelial tissue has two opposite sides, the outside of the epithelium(cavity), is known as the apical surface, and the inside is called the basal surface (this surface receives nutrients from the connective tissue by diffusion).
Cells on both surfaces are tightly connected, providing protection to the underlying connective tissue.
Finally, epithelial tissue also participates in the process of absorption of substances through the intestinal epithelium.
Based on your knowledge of signal amplification, which chemical messenger has the greatest potential to have a large compensatory response when starting with a very small concentration in blood?
Answer:
Hormones.
Explanation:
Hormones have a really low concentration in blood but are able to trigger a large response because they bind their receptors with extreme affinity, this means that even when there are just a few molecules, they will bind the receptor. Once this interaction happens, the receptor passes the information to the inside of the cell, interacting with many other molecules that continue passing the message to generate a response. Thanks to this, a single hormone can trigger interactions between hundreds of other molecules that amplify the signal, causing a large biological response.
Sickle cell disease (SCD) is caused by a recessive version of the hemoglobin gene. In the US, SCD occurs in about 0.2% of the newborn babies. In some African countries, 4% of the newborn babies have sickle cell. Out of a random sample of 10,000 newborn babies in the US, how many would you expect to be homozygous for the normal, dominant hemoglobin genotype assuming Hardy Weinberg equilibrium?
Final answer:
In the US, where 0.2% of newborns are affected by sickle cell disease, the expected number of homozygous dominant individuals in a sample of 10,000 newborns is estimated to be approximately 9,126, based on the Hardy Weinberg equilibrium calculations.
Explanation:
Sickle cell disease (SCD) is an autosomal recessive genetic disorder characterized by the production of abnormal hemoglobin, named hemoglobin S, which leads to the sickling of red blood cells. This sickling can block blood flow and cause a range of health issues. In the United States, 0.2% of newborns are affected by SCD.
In a population in Hardy Weinberg equilibrium, we can use the Hardy Weinberg principle to calculate the frequency of homozygous dominant individuals. The frequency of the recessive allele 'q' can be determined by taking the square root of the disease prevalence, which is 0.002 in the US (since 0.2% = 0.002). Applying this, we get q = √0.002 ≈ 0.0447. The frequency of the dominant allele 'p' can be calculated as p = 1 - q which gives us p ≈ 1 - 0.0447 = 0.9553.
The frequency of homozygous dominant individuals is p². So, p² = (0.9553)² ≈ 0.9126. In a sample of 10,000 newborns, the number of individuals homozygous for the normal hemoglobin genotype would be expected to be 10,000 * 0.9126 ≈ 9126.
Which of the following clues would tell you if a cell is prokaryotic or eukaryotic?a. whether or not the cell carries out cellular metabolismb. whether or not the cell contains DNAc. the presence or absence of ribosomesd. whether or not the cell is partitioned by internal membranese. the presence or absence of a rigid cell wall
Answer:
d. whether or not the cell is partitioned by internal membranes.
Explanation:
The prokaryotic cells are those which do not have a defined or definite nucleus because the nucleus is not bounded by the nuclear membrane. This type of nucleus is called nucleon. The prokaryotic cell also does not have membrane-bound cell organelles. Thus, the prokaryotic cell is not partitioned by internal membranes.
Whereas, a eukaryotic cell has a well-defined or definite nucleus and membrane-bound organelles such as mitochondria, chloroplasts, Golgi apparatus, endoplasmic reticulum. Thus, the eukaryotic cell is partitioned by internal membranes.