Answer:
A virus is a fragment of code embedded in a legitimate program. Virus are self-replicating and are designed to infect other programs. They can wreak havoc in a system by modifying or destroying files causing system crashes and program malfunctions. On reaching the target machine a virus dropper(usually trojan horse) inserts the virus into the system.
For more details, refer this.
Various types of virus :
File Virus : This type of virus infects the system by appending itself to the end of a file. It changes the start of a program so that the control jumps to its code. After the execution of its code, the control returns back to the main program. Its execution is not even noticed. It is also called Parasitic virus because it leaves no file intact but also leaves the host functional.
Boot sector Virus : It infects the boot sector of the system, executing every time system is booted and before operating system is loaded. It infects other bootable media like floppy disks. These are also known as memory virus as they do not infect file system.
boot sector virus flowchart
Macro Virus : Unlike most virus which are written in low-level language(like C or assembly language), these are written in high-level language like Visual Basic. These viruses are triggered when a program capable of executing a macro is run. For example, macro virus can be contained in spreadsheet files.
Source code Virus : It looks for source code and modifies it to include virus and to help spread it.
Polymorphic Virus : A virus signature is a pattern that can identify a virus(a series of bytes that make up virus code). So in order to avoid detection by antivirus a polymorphic virus changes each time it is installed. The functionality of virus remains same but its signature is changed.
Encrypted Virus : In order to avoid detection by antivirus, this type of virus exists in encrypted form. It carries a decryption algorithm along with it. So the virus first decrypts and then executes.
Stealth Virus : It is a very tricky virus as it changes the code that can be used to detect it. Hence, the detection of virus becomes very difficult. For example, it can change the read system call such that whenever user asks to read a code modified by virus, the original form of code is shown rather than infected code.
Tunneling Virus : This virus attempts to bypass detection by antivirus scanner by installing itself in the interrupt handler chain. Interception programs, which remain in the background of an operating system and catch viruses, become disabled during the course of a tunneling virus. Similar viruses install themselves in device drivers.
Multipartite Virus : This type of virus is able to infect multiple parts of a system including boot sector,memory and files. This makes it difficult to detect and contain.
Armored Virus : An armored virus is coded to make it difficult for antivirus to unravel and understand. It uses a variety of techniques to do so like fooling antivirus to believe that it lies somewhere else than its real location or using compression to complicate its code.
Answer: 1. nucleoid, capsid, envelope, enzymes.
A. Nucleoids represents the viral chromosomes, it is made up of single molecular which is either linear or coiling.
B. Capsid is the proteinacious covering around the virus that protects the nucleoids from damage and it consists of subunits called capsomere and campaigners.
C. Envelope is the loose membrane covering that occur in some viruses consisting of protein from lipids and carbohydrates(from host).
D. Enzymes are occasionally enzymes lysozymes is present in the region that comes in contact with host cell in bacteria pages.
2. Due to their nature of behaving like simple chemical compounds outside the living host.
3. Virus recognises it's host cell through the receptors they carry and virus can also trick the cell into taking them by bulk transport called endocytosis.
4. The development of CRISPR immune system to fight against phages.
5. Lytic involves reproduction of viruses by using host cell for virus manufacturing while lysogenic cycles involves integration of viral genome into host DNA and reproducing with it.
6. The life cycle of hic
a. Attachment and entry- this happens in two stages attachment and fusion.
B. Reverse Transcription- when hiv enters the cell it must be reverse transcribed into proviral DNA before integrating into the DNA of host.
C. Integration- after conversion into DNA, hiv integrate enzyme attaches itself to the proviral DNA strands it passes through the wall of cell nucleus.
D. Transcription and Translation- they become active when they encounter an infectious agent.
7. Bacterial viruses are classified under viruses that affect the ecoil.
-DNA phages of T series where the T phages of ecoil are larger lyric phages that contain single molecule of double stranded DNA
-Temprate pages: bacterial phage lambda
-Small DNA phage: the genome of some bacteria phage encoded 10-12 protein
-RNA phage- some e coil bacterial phage contains a genome composed of RNA instead of DNA.
B. ANIMAL viruses are classified by genome type and MNRA synthesis path way.
-DNA viruses (classes 1 and 2) commonly used in the study of DNA replication.
-RNA viruses(classes 3 and 4) have RNA genome and all animal cells belong to this class.
8. They are made of protein.
They contain genetic codes needed for reproduction.
-viruses do not fit our normal life because viral reproduction is not possible without a host cell and it doesn't consume energy to survive that is metabolic processes within the cell.
9. The DNA sequences which can move around the genome changing their number of copies or location often affecting the nearest genes.
- plasmids and trasposoons are mobile transferable genetic elements through bacterial conjugation which is a horizontal mechanism gene transfer while viruses can move due to their adaptive replication strategy.
10. They cause infectious diseases by entering a living and normal cell, thereby using the cell to reproduce other viruses of them selves and infecting the immune system of the living cell.
11. -introduction of viral pathogens into a new host species.
-establishment of pathogens in New host.
-dissemination of pathogens among large number of individual of new host species.
12. In a nut shell, transmission of viruses occur horizontally is the transmission of viruses among plants of same generation while vertical transmission is between full grown plants and the seed from it to ensure transmission from current generation to the next generation.
13. Virions is the infectious form of viruses as it exists outside the host cell designed for transmission of nucleic acid genome amongst hosts while a prion is neither bacterial nor fungal nor viral and contains no genetic materials.
Explanation:2. They have long and non living thing characteristics in nature.
4. This is an act of copying a snipet of phages they come in contact with into a memory to help build against subsequent attacks by viruses in future.
6. The life cycle of hiv consists of 4 stages which includes the process of entering , reverse integration where the RNA enzymes reverse transcribed into DNA , integration where it passes through the walls of the cell and finally the last stage where it becomes activated.
N.B
Most of the answers required explanations above in order to avoid repetition of answers.
The process in which related dna sequences from two different sources are exchanged is called
Answer: Homologous Recombination
Explanation:
In DNA recombination, homologous recombination is a type of gene repair in which nucleotide sequences are exchanged between two identical molecules of DNA.
When DNA damages occur such as DNA double-stranded breaks or DNA gaps during DNA synthesis.
To conserve genome, cells uses a homologous recombination (HR), a type of DNA repair.
In genetic engineering a foreign DNA with identical nucleotide sequence similar to that of the missing DNA gaps or breaks are introduced into a target cell. The cell recognizes the identical DNA sequences as homologues, causing target gene to be exchanged with the foreign DNA sequence during DNA repair.
HR also occur naturally.
Crossing over is the exchange of DNA sequences between non-sister chromatids of homologous chromosomes during meiosis I, leading to recombinant chromosomes and increased genetic variation.
Explanation:The process in which related DNA sequences from two different sources are exchanged is known as crossing over. This biological mechanism occurs during meiosis I, when homologous chromosomes pair closely together. During crossing over, non-sister chromatids exchange genetic material, which results in the formation of new combinations of genes, or recombinant chromosomes.
The purpose of crossing over is to increase genetic diversity within a species. It is a critical part of sexual reproduction and ensures that offspring have a unique combination of DNA from both parents, leading to genetic variation within a population. The process is also known as recombination, and the points where the chromatids break and rejoin are called chiasmata.
Explain the importance of microbes. Distinguish between aerobic respiration and anaerobic respiration (fermentation). What two processes sustain ecosystems and the biosphere and how are they linked?
Answer: Importance of Microbes - serving to ferment foods, produce fuel, enzymes and bioactive compounds.
Aerobic (fermentation) uses oxygen anaerobic (fermentation) does not use oxygen.
Processes energy flow and nutrient cycling.
(How are they linked?) These two processes are linked through the natural services that are components of the earth.
Microbes are vital for nutrient cycling, decomposition, and bioremediation in ecosystems. Aerobic respiration uses oxygen to produce energy efficiently, while anaerobic respiration (fermentation) occurs without oxygen, producing energy less efficiently but essential in environments lacking oxygen.
Importance of Microbes:
Microbes play a crucial role in various ecological processes and are essential for the maintenance of life on Earth. They are involved in nutrient cycling, such as the fixation of nitrogen from the atmosphere, making it available to plants, and the decomposition of organic matter, which recycles nutrients back into the ecosystem. Microbes are also used in industrial processes, such as the production of antibiotics, enzymes, and biofuels. Additionally, they are vital components of the human microbiome, influencing human health by aiding in digestion, producing vitamins, and protecting against pathogens.
Aerobic Respiration vs. Anaerobic Respiration (Fermentation):
Aerobic respiration is a metabolic process in which cells use oxygen to convert glucose into energy (ATP). The complete breakdown of glucose results in the release of carbon dioxide, water, and a large amount of energy. The general equation for aerobic respiration is:
[tex]\[ C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{energy (ATP)} \][/tex]
Anaerobic respiration, or fermentation, occurs in the absence of oxygen. In this process, glucose is only partially oxidized, and the final electron acceptor is an organic molecule, such as pyruvate, which is converted into various products like ethanol, lactic acid, or hydrogen gas, depending on the organism and conditions. The energy yield in anaerobic respiration is much lower than in aerobic respiration. A general equation for fermentation might be:
[tex]\[ C_6H_{12}O_6 \rightarrow 2C_2H_5OH + 2CO_2 + \text{less energy (ATP)} \][/tex]
Two Processes Sustaining Ecosystems and the Biosphere:
The two fundamental processes that sustain ecosystems and the biosphere are photosynthesis and respiration. Photosynthesis is the process by which plants, algae, and certain bacteria convert light energy into chemical energy, storing it in glucose. This process also produces oxygen as a byproduct, which is essential for aerobic respiration. The general equation for photosynthesis is:
[tex]\[ 6CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2 \][/tex]
Respiration, as previously discussed, is the process by which organisms convert nutrients into energy (ATP). This energy is used to fuel cellular activities. Respiration can be aerobic or anaerobic, depending on the presence or absence of oxygen.
Link Between Photosynthesis and Respiration:
Photosynthesis and respiration are linked in a cyclical manner. Photosynthesis captures energy from sunlight and stores it in organic compounds like glucose, which are then used by organisms during respiration to release energy for various life processes. During photosynthesis, oxygen is produced, which is necessary for aerobic respiration. Conversely, the carbon dioxide released during respiration is used as a substrate for photosynthesis. This interdependence forms the basis of energy flow and matter cycling within ecosystems and the biosphere as a whole.
The _____________ is primarily responsible for the identification, diagnosis, and design of the treatment plan and curriculum for children with communication, language, and speech disorders.
Answer:
The correct answer is Speech-language pathologists.
Explanation:
There is a type of language disorder which treats people who have trouble understanding other people and expressing themselves.
This should be distinguished from speech disorder, which is when a person has difficulty producing sounds or speaking fluently.
Those who work to help people with these types of disorders are called Speech-language pathologists. They are professionals who are responsible for the identification, diagnosis, and design of the treatment plan and curriculum for children with communication, language, and speech disorders.
They usually form teams with other professionals such as therapists, teachers, audiologists, etc.
Together they try to solve the problems presented by this disorder that are usually semantic or grammatical problems, difficulty in social communication or problems to relate the sound of a word with its meaning, among others.
Pumps move substances ____________ a concentration gradient, a process that requires energy. Channels instead provide the means to move a substance ____________ a concentration gradient. Neurons contain the following major types of channels: • Channels that are always open, allowing continuous diffusion of a specific ion from a region of ____________ concentration to a region of ____________ concentration are leak channels. • Channels that are normally closed that open in response to the binding of a ____________ are chemically gated channels. When open, they allow a specific ion to ____________ across the plasma membrane. • Channels that are normally closed, but open in response to changes in ____________ across the plasma membrane are voltage-gated channels. When open, they allow a specific ion to diffuse across the membrane.
The answers to the blank spaces are: against, with, higher, lower, ligand, flow, membrane potential. All answers stated respectively .
What is concentration gradientThe difference between two areas' concentrations of a material is referred to as a concentration gradient. It is the difference in concentration over a certain distance, usually between two areas of different concentrations. It could be a molecule, an ion, or another type of chemical compound.
Traveling "against" the concentration gradient entails traveling from a region of higher concentration to a region of lower concentration, while moving "with" the concentration gradient entails doing the opposite.
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Using the 10 percent rule, explain why there is typically smaller populations of quaternary consumers compared to primary consumers in an ecosystem.
Answer:
As we know 10% law is transfer of energy from higher trophic level to lower trophic level. So as the energy are transfer from one organism to another there is a loss of energy as that energy are utilised by the oragnism and only 10% of the total energy is transferred to the second consumer.
Explanation:
Quetinary consumer are at the higher position in the food chain so they do not get enough energy from prey they have to feed on several organism for the enegy. And also they are at the top of the food chain so they are not eaten by other animal, their life span are also more than primary consumer.
In other hand primary consumer get enough energy but they are prey for other higher tropic level.
Primary and secondary consumer are maintend in such a way by the nature thats make a ecological balance of the habitant.
Superoxide turns toxic to cell membrane by association with free radical of ________.A) Nitric oxideB) Hydrogen peroxideC) Sulfur dioxideD) Aminoxyls
Answer:
Nitric oxide.
Explanation:
Superoxide may be defined as the compounds that contain the superoxide anions like oxygen anion (O2-). This is also known as the reactive oxygen species.
These anions are generated by the immune system to kill the pathogens. These superoxide include the species like NO, NO2. These super oxide anions are toxic to the cell membrane and also plays an important role in the process of ageing.
Thus, the correct answer is option (A).
Which of the following definitions is INCORRECT? Which of the following definitions is INCORRECT? epidemic: a disease that is constantly present across the world endemic: a disease that is constantly present in a population pandemic: a disease that affects a large number of people in the world in a short time incidence: number of new cases of a disease
Answer:
epidemic: a disease that is constantly present across the world.
Explanation:
An epidemic is a sudden outbreak of a disease that spreads over a large area within a short period.
Endemic disease is a disease that is found regularly within an area at every point in time.
Pandemic disease is a disease that is prevalent over the whole world within a short period.
Incidence is the number of newly reported cases of a disease.
From the definition of each of the term. epidemic is the only one defined incorrectly of all the options.
The incorrect definition is that of an endemic disease, which is correctly defined as a disease that is always present at low incidence, not high incidence, in a population.
Explanation:The definition provided in the question that is INCORRECT is that of an endemic disease. The correct definition is that an endemic disease is one that is constantly present, usually at low incidence, in a population, not at high incidence as suggested in one of the erroneous definitions. In contrast, an epidemic is an outbreak of a disease that occurs in an unusually high number of individuals within a population at the same time. A pandemic is an epidemic that becomes widespread across multiple populations or continents, or even worldwide. Incidence refers to the number of new cases of a disease that appear in a population during a specific period of time. These terms are crucial for understanding the spread of diseases and for public health management.
Suppose that, while on a forest hike, you notice a blue fungus and a pink plant growing along the hiking trail. As you continue walking, you observe that if a blue fungus and a pink plant are growing side by side, they are both much larger than if the fungus and the plant are farther apart. What can you hypothesize about the relationship between the fungus and the plant?
Answer:
Symbiosis can be described as a biological interaction between organisms of different species.
There are different forms of symbiosis. A type of symbiosis in which both the organisms benefit from each other is called as mutualistic symbiosis.
The blue fungus and the pink plant are able to grow more in size when placed side by side because they undergo symbiosis. They both help each other and develop a symbiotic relationship which allows both of them to have enhanced growth.
Connective tissue is different from other major tissue
a) types in that it covers the surface of the body.
b) has cells that are sparsely scattered through a nonliving matrix.
c) is made of cells.
d) conducts electrical impulses throughout the body.
Answer:
The correct answer is b) has cells that are sparsely scattered through a nonliving matrix.
Explanation:
Connective tissue is the most diverse and widespread of the body. It can be found in bone, ligaments, tendons and more. It's one of its main characteristics is the presence of cells in a matrix called ground substance.
A biochemist isolates, purifies, and combines in a test tube a variety of molecules needed for DNA replication. When she adds some DNA to the mixture, replication occurs, but each DNA molecule consists of a normal strand paired with numerous segments of DNA a few hundred nucleotides long. What has she probably left out of the mixture?a. DNA ligase
b. nucleotides
c. DNA polymerase III
d. Okazaki fragments
Answer:
a. DNA ligase
Explanation:
DNA ligase is the enzyme of DNA replication that joins DNA segments together by catalyzing the formation of new phosphodiester bonds. These reactions use the energy of ATP molecules to form the bonds. The function of the DNA ligase enzyme is to join the Okazaki fragments together which in turn are formed during replication of the lagging strand. In the absence of DNA ligase, the Okazaki fragments cannot be joined together.
According to the given information, the process of DNA replication obtained shorts DNA segments of a few hundred nucleotides. This means that the reaction mixture lacked the DNA ligase enzyme and the DNA segments could not be joined together.
is a disease that affects the voluntary muscles (those controlled by one's will) in which nerve impulses are impaired, resulting in fatigue, weakness, and difficulties controlling muscles.
Answer:
Myasthenia gravis
Explanation:
Myasthenia gravis is an uncommon (20 per 100000) chronic autoimmune neuromuscular disorder characterized by weakness in the skeletal muscles that worsens with exertion and improves with rest, this happens due to an error in the transmission of nerve impulses to the muscle. Its causes are unknown but it is treatable.
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Ruth is quite attractive (a 4 on a 5-point scale), but Naomi is strikingly attractive (a 5 on a 5-point scale). Research suggests that if Ruth makes $35,000 a year on her job, Naomi will probably make _____ doing the same job. slightly less money the same amount more money significantly less money
A. Slightly less money
B. the same amount
C. More money
D. Significantly less money
Answer:
The correct answer is C. More money.
Explanation:
There' a correlation that has been studied, between physical appearance and the money that people get paid. It's a psychological factor that leads to handsome people being paid more and not so pretty people being paid less. Therefore, as Naomi is more attractive, she will be paid more.
All the following are true of the movement of Earth's atmosphere except :
a.cool air is denser than warm air so it tends to sink toward the Earth's surface.
b.the movement of air within the atmospheric convection cells generates the Earth's major wind belts.
c.a column of cool, dense air produces high pressure at the Earth's surface. a column of warm, less dense air produces low pressure at the Earth's surface.
d.warm air is less dense than cool air so it tends to sink toward the Earth's surface.
Final answer:
The accurate statement about Earth's atmosphere movement is that warm air rises because it is less dense, and cool air sinks due to higher density. This creates convection currents which are essential in generating wind belts and pressure systems.
Explanation:
The correct answer to 'All the following are true of the movement of Earth's atmosphere except:' with the listed statements is option d: warm air is less dense than cool air so it tends to sink toward the Earth's surface. This statement is false because in reality, warm air is less dense and therefore it tends to rise, not sink. This rising of warm air and the sinking of cooler air form convection currents, which are a major factor in the movement of Earth's atmosphere.
The rest of the statements are true: a. cool air is denser than warm air so it tends to sink, b. the movement of air within the atmospheric convection cells generates the Earth's major wind belts, and c. a column of cool, dense air produces high pressure at the surface while a column of warm, less dense air produces low pressure.
When examining the two complementary strands of nucleotides in one DNA molecule, it would be expected that the sum of ________ in one strand would be ________ the sum of the ________ in the other strand.
Answer: Purine; is equal to; pyrimidine
Explanation:
When a segment of DNA is examined then the nucleotide in one DNA molecule, it will be expected that the sum of purine in one strand will be equal to the sum of the pyrimidine in the other strand.
Adenine combines with Thymine and Cytosine combines with Guanine in 1:1 ratio.
More specifically the ratio of purine is to pyramidine is 1:1 in an organism. This pattern is seen in both the strands of the DNA.
Final answer:
When examining the two complementary strands of nucleotides in one DNA molecule, it would be expected that the sum of adenine (A) in one strand would be equal to the sum of the thymine (T) in the other strand, and vice versa.
Explanation:
Similarly, the sum of guanine (G) in one strand would be equal to the sum of the cytosine (C) in the complementary strand. This relationship is due to the rules of base pairing, where adenine always pairs with thymine, and guanine pairs with cytosine.
These rules are fundamental to the structure of DNA and its replication process, ensuring that each new molecule is an accurate copy of the original.
Robert’s fraternal twin sister Desiree has a diagnosis of schizophrenia. Armend’s identical twin brother, Nigel, also has a diagnosis of schizophrenia. Robert, compared with Armend, probably has a ______ chance of having a diagnosis of schizophrenia. A. lower
Answer:
The correct option is lower.
Explanation:
Schizophrenia can be described as an inherited disease and it is a type of mental illness. As Armend has an identical twin brother with diagnosis of schizophrenia hence, he will have more chances than Robert whose fraternal twin sister has schizophrenia.
As fraternal twins develop from two different eggs hence, the chances in them having the same disease will be lower. Identical twins develop from the same egg, hence they will have more chances of having the same inherited disease.
Robert, who has a fraternal twin with schizophrenia, likely has a lower chance of being diagnosed with schizophrenia compared to Armend, who has an identical twin with the condition, because identical twins share more genetic material than fraternal twins.
Explanation:The question asks about the likelihood of Robert, who has a fraternal twin sister with schizophrenia, compared to Armend, who has an identical twin brother with the same diagnosis, in having schizophrenia himself. From a genetic point of view, Armend, having an identical twin with schizophrenia, has a higher chance of developing the disorder compared to Robert, who has a fraternal twin sister with the condition. This is due to the fact that identical twins share all of their genetic material, while fraternal twins only share about half, similar to any siblings. The statistics also show that environmental factors play a role, but the genetic risk is significant.
Based on the provided information, which highlights that adoptees with a high genetic risk have a significantly higher likelihood of developing schizophrenia when raised in disturbed environments compared to those raised in healthy environments, it's important to note that while the environment is influential, genetics carry substantial weight in the risk for developing schizophrenia. However, in the context of this question, we are comparing fraternal to identical twins, which implicates the genetic factor as the primary variable. Therefore, it is likely that Robert has a lower chance of having a diagnosis of schizophrenia compared to Armend.
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As children grow, they generally consume more calories, decide if they want to eat, and how much they want to eat. What is the rule-of-thumb guideline to determine an age-appropriate serving size for a 3-year-old?
A) 3 teaspoons
B) 2 tablespoons
C) 3 tablespoons
D) Equal to that of an adult
Answer:
Option C
Explanation:
In general, the amount of nutrient served to an adult is equal to 50% of the nutrient served to adults. The amount of calories consumed by an adult is equal to 2000 to 2800 calories per day. Therefore, the calories required by a young kid is equal to 1000 to 1400 calories per day. Considering this, a nutrient feed of 3 tablespoon is sufficient to cater the calorie requirement of young children of age above 3 years
Hence, option C is correct
During which processes does independent assortment of chromosomes occur?
Independent assortment occurs during anaphase I of meiosis I and to some extent during metaphase II and anaphase II, leading to the formation of gametes with diverse combinations of paternal and maternal chromosomes.
Explanation:Independent assortment of chromosomes occurs during meiosis, a critical process for producing genetically diverse gametes in eukaryotic organisms. Specifically, this event takes place during anaphase I of meiosis I, where bivalent chromosomes separate, and again, although indirectly, during metaphase II and anaphase II as sister chromatids segregate. During the phase of prophase I, chromosomes align randomly at the metaphase plate, setting the stage for the independent assortment. The physical basis for the law of independent assortment lies here, as different homologous pairs line up in random orientations, allowing any combination of paternal and maternal chromosomes to segregate into each gamete, thus increasing genetic variation.
Additionally, recombination or chromosomal cross-over during meiosis further increases genetic diversity by producing new combinations of alleles. At the end of meiosis II, four different gametic combinations are produced, each containing a haploid set of chromosomes. As the number of chromosomes increases, the number of possible assortment combinations increases dramatically, leading to a vast potential for genetic diversity.
Dated to approximately 500,000-400,000 years ago, the site of _______ has yielded a sample of 4,000 fossil fragments representing about 28 premodern Homo sapiens individuals, more than 80% of all Middle Pleistocene hominin remains in the world.
a. Steinheim
b. Ehringsdorf
c. Sima de los Huesos
d. Petralona
e. Swanscombe
Answer:
c. Sima de los Huesos
Explanation:
Genetic variation leads to genetic diversity in populations and is the raw material for evolution. Biological systems have multiple processes, such as reproduction, that affect genetic variation. They are evolutionarily conserved and shared by various organisms.
Which statement best represents the connection between reproduction and evolution?
A) Plants that use sexual reproduction are rare since this type of reproduction in plants does not contribute to genetic diversity.
B) In order to increase genetic diversity for evolution in sexually reproducing organisms, mutations must occur in the zygote after fertilization.
C) Since prokaryotic organisms reproduce asexually, there is no mechanism for them to add genetic diversity for evolution.
D) Sexual reproduction increases genetic variation because random mutations can be shuffled between organisms.
Answer:
D) Sexual reproduction increases genetic variation because random mutations can be shuffled between organisms.
Explanation:
Sexual reproduction involves the combination of two gametes from two different parents one from the male parent and another from female parents. So as the two different gene combination occurs in sexual reproduction, therefore, it increases the genetic variation.
Also, the random mutation that occurs in the DNA can be shuffled between organisms during the fertilization event of reproduction. This increases the genetic variation because new alleles and genes get added to the gene pool. So good mutation is selected naturally and through reproduction, it passes to a new generation. So the right answer is D.
Mutation and sexual reproduction are the two main mechanisms that contribute to genetic diversity in a population. Mutation introduces new alleles and can have various effects on the phenotype, from reducing fitness to providing a beneficial advantage. Sexual reproduction brings together unique combinations of alleles from two parents, resulting in genetic diversity among offspring.
Explanation:Genetic diversity in a population comes from two main mechanisms: mutation and sexual reproduction. Mutation, a change in DNA, is the ultimate source of new alleles, or new genetic variation in any population. The genetic changes caused by mutation can have one of three outcomes on the phenotype. A mutation can affect the phenotype of the organism in a way that gives it reduced fitness-lower likelihood of survival or fewer offspring. Alternatively, a mutation may produce a phenotype with a beneficial effect on fitness. And, many mutations will also have no effect on the fitness of the phenotype; these are called neutral mutations. Mutations may also have a whole range of effect sizes on the fitness of the organism that expresses them in their phenotype, from a small effect to a great effect. Sexual reproduction also leads to genetic diversity: when two parents reproduce, unique combinations of alleles assemble to produce the unique genotypes and thus phenotypes in each of the offspring.
At the conclusion of an interventional radiographic examination, the examination room is cleaned and major components are wiped down with chemical disinfectants. By performing this important task the radiographer is practicing_________.a. medical asepsis.b. sterilization.c. surgical asepsis.d. fomite asepsis
Answer: A medical asepsis
Explanation:
Medical Asepsis: this is one of the principles of sterile techniques. It is the state of having a sterile equipment and facility free from disease causing micro-organisms such as germs, bacteria, viruses, and other diseases causing microorganisms.
The answer is Medical asepsis and it is concerned mainly with eliminating the spread of disease causing microorganisms through facility practices, to prevent the spread of disease microorganisms from one patient to another.
Cholecalciferol (an inactive form of vitamin D) must undergo 2 conversion steps before it becomes the active form of vitamin D, calcitriol. Those steps take place in the _____ and the _____
Answer:
Those steps take place in the liver and the kidneys.
Explanation:
Cholecalciferol, which is the inactive form of vitamin D, is first transported in the blood via vitamin D binding protein (DBP) to the liver.
Upon reaching the liver, cholecalciferol will undergo chemical changes, forming calcidiol, the deposit form of vitamin D.
After that, calcidiol goes to the kidneys, which will form calcitriol, the metabolically active form of vitamin D.
Cholecalciferol must be converted in both the liver and the kidney to become the active form of vitamin D, known as calcitriol. In the liver, it becomes calcidiol, and then in the kidney, it is finally converted to calcitriol, regulating vital bodily processes.
Explanation:Cholecalciferol, an inactive form of vitamin D, must undergo two conversion steps before it becomes the active form of vitamin D, calcitriol. These steps take place in the liver and the kidney.
In the liver, cholecalciferol is hydroxylated to become 25-hydroxycholecalciferol (calcidiol), also known as 25(OH)D. This is the main circulating form of vitamin D in the blood. From there, it travels to the kidney, where it undergoes another hydroxylation step. The kidneys convert calcidiol into 1,25-dihydroxycholecalciferol (calcitriol), which is the biologically active form of vitamin D. This transformation is crucial for regulating calcium and phosphorus levels in the blood and is important for maintaining healthy bones and teeth among other physiological processes.
A crime scene reveals a tiny amount of genetic material that may be linked with the guilty person. This small amount of DNA may be amplified, or copied many times over, through a process called ___________ ___________ ___________.
Answer:
Polymerase Chain Reaction (PCR)
Explanation:
Polymerase chain reaction is a molecular biology procedure/technique used to amplify or multiply specific segments of a DNA. The process makes use of taq polymerase (an enzyme), primers, the DNA of interest and nucleotides.
All the reactants are subjected to repeated heating and cooling cycles during which the DNA of interest is synthesized in multiples. The process can be broken down to 3 basic steps:
Denaturation of the target DNA by heat to separate the DNA strandsBinding of primers to their complementary DNA sequence at lower temperatureSynthesis of new DNA through addition of nucleotides to primers by the taq polymerase. This happens at higher temperature than the second step but lower than the first step.The steps are repeated at the end of each cycle which can last between 2 to 4 hours depending on the length of the target DNA. Newly synthesized DNA at every cycle forms a template for the production of another strand. Hence, multiple copies of the target DNA can be produced within a short period.
When two frog species, Rana pipiens and Rana sylvatica, mate, the offspring die early in embryonic development. This is an example of ________.
a) hybrid sterility
b) reduced hybrid fertility
c) reduced hybrid viability
d) mechanical isolation
Answer:
The correct answer is c) reduced hybrid viability.
Explanation:
As the offspring dies early in embryonic development, it's possible to understand that the organism isn't viable, which is very common among hybrid organisms as well as their sterility or reduced fertility.
Improve the student’s model of gas exchange by drawing the missing component.
The diagram can be improved by:
Lungs
↓
oxygen
↓
Red blood cells (carrying oxygen)
↓
Organs (like stomach and liver etc) from where carbon is taken and oxygen is supplied
↓
RBC's carrying Carbon dioxide to the lungs
Lungs: The lungs are where oxygen is taken in during the process of breathing. Oxygen is a vital element required by the body for cellular respiration.
Red Blood Cells (carrying oxygen): Red blood cells (RBCs) are specialized cells in the bloodstream responsible for carrying oxygen from the lungs to different parts of the body. They contain a protein called hemoglobin, which binds with oxygen in the lungs and carries it to where it is needed.
Organs (like stomach and liver, etc.) from where carbon is taken and oxygen is supplied: This part of the diagram signifies that various organs in the body, including the stomach and liver, require oxygen for their metabolic processes. They receive oxygen from the red blood cells to function properly. At the same time, these organs produce carbon dioxide (a waste product) as a result of their metabolic activities.
RBC's carrying Carbon dioxide to the lungs: After delivering oxygen to the organs, the red blood cells pick up carbon dioxide, which is a waste product of cellular metabolism. The red blood cells then carry this carbon dioxide back to the lungs.
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Which of the following statements are true regarding fatty acids?
I. Fatty acids with fewer than 14 carbons are the most common.
II. Synthesis of fatty acids occurs in 2 carbon units.
III. Fatty acids with conjugated double bonds are the most common type of fatty acid.
IV. In higher plants and animals, C16 and C18 species predominate.
Answer:
Option (I) and (IV).
Explanation:
Fatty acids may be defined as the carboxylic acid that contains the long aliphatic chain. Fats are generally of two types - saturated fatty acid and unsaturated fatty acid.
The fatty acids are generally synthesized in the two carbon units. This helps in the proper synthesis of fat. The fatty acids that are most common in plants and animals are palmittic acid or the fats that contain C16 and C18 species predominate.
Thus, the correct answer is option (I) and (IV).
Look at the cross section of a cell membrane of a eukaryotic cell. H+ ions are being pumped from a low concentration to a high concentration. transport How do you describe this type of transport across the cell membrane?
Answer:
it is an active transport
Explanation:
Active transport involves movement of ions or molecules against a concentration gradient (from region of lower concentration to region of higher concetration) using energy from hydrolysis of ATP as the drive
Answer:
Active Transport is the answer
Explanation:
Receptors found in signal transduction
a.are always found in membranes.
b.are always found in the cytoplasm.
c.are always found in the nucleus.
d.can be found either in the membrane, cytoplasm, or nucleus.
The registered nurse is teaching the student nurse about care provided for clients according to the five level triage system of the Emergency Severity Index (ESI). Which statement made by the student nurse indicates effective learning? Select all that apply:
a. "Clients in the ESI-2 category do not have life-threatening injuries."
b. "Clients who are in the ESI-4 category present with stable vital signs."
c. "The ESI-1 clients should be seen by the physician within 10 minutes."
d. "Clients with severe respiratory distress fall within the ESI-1 category."
Student nurse indicates effective Clients who are in the ESI-4 category present with stable vital signs, and Clients with severe respiratory distress fall within the ESI-1 category.
Answer: Option B & D
Explanation:
The ESI has developed by many hospitals from all over the countries in the world. It stands for Emergency Severity Index that is a 5 level algorithm categorizing the patient's degree of emergency for the treatment.
They can be mentioned as ESI 1-5 and in terms of Immediate, high risk, medium risk, low risk and stable. Respiratory distress falls within ESI-1 because the chance of pursuing life at risk is more than high-risk situations.
ESI-4 is a low-risk state where the patient can be little stable. This state shows the signs of being stable that is only one resource has to cured to get stable.
appointment and learns that her baby weighs about 9 ounces and is covered with lanugo. She has felt some slight movements from the baby recently. About how many weeks along is she in her pregnancy?
A.28 weeks
B.20 weeks
C.10 weeks
D.16 weeks
Answer:
The correct answer is option B.20 weeks.
Explanation:
By week 20 the mother will already find a pregnancy in half way, remember that a pregnancy lasts 40 weeks.
At this stage the baby's facial features begin to take shape, and the baby begins to develop a sleep-wake cycle. Another feature is that it will probably start sucking its finger.
It is possible that the mother already begins to feel slight movements from her baby in week 20, which should be weighing between 9 and 11 ounces of pounds.
For this week, the baby's skin is covered with an amniotic fluid and a waxy covering that is called vernix.
This vernix is associated with the lanugo, which helps it maintain and is a type of fine and soft hair.
AZT is an effective drug for treating HIV-infected individuals because it prevents the replication of new viral particles. The HIV virus has a genome made of RNA. Of the following, which represents the most likely target for the action of AZT?a. DNA polymeraseb. RNA polymerasec. reverse transcriptased. DNA ligase
Answer:
Enzyme reverse transcriptase RT
Explanation:
This enzyme is what is needed by the virus to make several copies of itself. Reverse transcriptase is inhibited by this drug thereby reducing the numbers of the virus. The drug is a nucleoside analog of thymidine