Describe the three main steps of each cycle of PCR amplification and what reactions occur at each temperature.

Answer: Birds option c is correct.

Explanation: Birds represents an example of natural reservoir host for the three zoonotic pathogens. For example poultry for salmonellosis and influenza from which house cats, humans and birds of prey can be infected. In the case of Toxoplasma gondii pigeons represent a better example of reservoir host.

Answer:

a. disruption of mitotic spindle formation.

Explanation:

Vinblastine is a chemotherapeutic drug which is used to restrict cancer cell proliferation. During metaphase, it binds to microtubular proteins which play a very important role in mitotic spindle formation. If spindles will not form then during anaphase, the sister chromatids will not separate and mitosis will not take place. This is how hyper-proliferative cancerous cells are controlled from dividing and cancer is treated using this drug.

Answer:

The correct answer is option B. B cells.

Explanation:

An antibody-mediated immune response is an immune response that involves the B cells to recognize the antigen or pathogen present in the blood or the lymph of an individual that is the reason it is also known as the humoral immune response.

The primary response in the antibody-mediated response is B cells as they are activated by the chemicals released by the helper T cells and start producing plasma B cells and memory B cells.

Thus, the correct answer is option - b. B cells.

Answer:

The structure and function of DNA .

Explanation:

DNA is present as genetic material in almost all organism except some viruses. The DNA is made of pentose sugar, nitrogenous bases and the phosphate group.

The composition of the DNA remains same in almost all organism. Four nitrogenous bases of DNA are adenine, guanine, thymine and cytosine in almost all organism. The flow of genetic material and DNA replication occurs is similar in all the organisms. DNA shows unity among all the organism.

Thus, the correct answer is option (c).

The best representation of unity among all organisms is the structure and function of DNA due to its universal presence and role in defining biological structure and function across all life.

The best demonstration of the unity among all organisms is c. the structure and function of DNA. DNA, deoxyribonucleic acid, is consistent across all living organisms, acting as the instruction manual for cells and thus, overall biological structure and functionality. It unifies organisms as it is a universal code for life. Remarkably, despite the vast diversity of life on Earth, DNA serves as a fundamental similarity linking all forms of life. Each organism, from bacteria to blue whales, uses essentially the same mechanisms to read, interpret, and express DNA. This shared characteristic is a profound marker for unity among all organisms.

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Answer:

Explanation:

This is because of the fact that genomes of the organisms exhibit gene families and superfamilies. These contain genes that typically encode for proteins with similar aminoacid sequences, the proteins form by these aminoacids perform related functions. In this way the genes and their functions are duplicated among the gene families. This duplication of genes prevents the divergence from mutation.

Answer:

D. Interferons

Explanation:

Interferons are the chemical signals (secretary proteins) responsible for activating non-infected cells so that they could fight a virus. In case of a viral infection, a cell infected by virus release interferons to let neighboring cells know the presence of a virus so that they could enhance their  anti viral defense.

Interferons are of 3 types:

1) Interferon α

2) Interferon β

3) Interferon γ

Interferon α & β are secreted by white blood cells while interferon γ is mainly synthesized by natural killer cells.

Answer: B. True

Explanation:

The tissue tropism can be define as the ability of the microbe to infect specific cells and tissues of the host that supports the growth of particular microbe like virus and bacteria.

Some viruses have broad tissue tropism they can infect many cell types. Other viruese can infect only single cell or tissue type.

Answer:

b. cis test

Explanation:

A test that is used to determine if the mutation associated with a given phenotype is due to mutations in two different genes or due to different alleles of the same gene is called a complementation test.

A complementation test is also called as a cis-trans test.

If the mutations in a complementation test are located on the same position then the genes are termed as being on the cis position otherwise on the trans-position.

A cis test, that is if the genes are located on the same position serves as a control for the complementation test.

The control for a complementation test, which is often omitted, is the b. cis test.

In genetics, the complementation test is used to determine whether two mutations that produce a similar phenotype are in different genes or in different sites within the same gene. The test involves crossing two mutants to see if their offspring have the wild type phenotype, indicating complementary mutations. The control for this test is the cis test, where both mutations are present on the same piece of DNA. This confirms whether the mutations can complement each other when in close proximity, which is necessary for an accurate complementation test. Without this control, one might incorrectly conclude complementation when, in reality, the two mutations could interact in a cis configuration to produce a wild type phenotype.

Answer:

Vasodilation:

Vasodilation may be defined as the dilation of the blood capillaries around the skin. The blood capillaries gets widen. The vascular resistance to the blood flow decrease. The blood pressure near the skin decreases. The increase in temperature may cause vasodilation.

Vasoconstriction:

Vasoconstriction may be defined as the constriction of the blood capillaries around the skin. The blood capillaries gets narrow. The vascular resistance to the blood flow increases. The blood pressure near the skin increases. The decrease in temperature may cause vasoconstriction.

Vasodilation is the widening of blood vessels that allows for increased blood flow and promotes heat loss, while vasoconstriction is the narrowing of blood vessels that reduces blood flow and conserves heat by vital organs. These processes help regulate body temperature and blood pressure.

Vasodilation and vasoconstriction are biological processes related to the control of blood flow in the body. Vasodilation is the widening of blood vessels, it occurs when the smooth muscles in the walls of the blood vessels relax, thereby increasing blood flow. This process allows for radiation and evaporative heat loss. On the other hand, vasoconstriction is the narrowing of blood vessels, it happens when the smooth muscles in the vessel walls contract, reducing blood flow. This process brings blood to the core to conserve heat by vital organs. The balancing act between these two processes helps regulate body temperature and blood pressure.

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Answer:

The correct answer is option D. Individuals.

Explanation:

Natural selection is the process in which some individuals adapt traits or trends according to the environment changes in order to service and reproduce more. These trends are pass from one generation to another generation.

Natural selection is the first time described by Charles darwin.

Thus, the correct answer is option-

d. individuals

Some individuals survive and can reproduce better compared to others.

Natural selection is a method of selection of the organisms that have adapted to the change in their environment and can survive and reproduce in the variation.

Individuals having better traits and attribute over others can survive and even can continue the generation of the species as they have adapted to the frequency change of the allele.

The alleles are the alternative gene form for a particular trait and characteristic and are located on the chromosome of the organism as they get passed from generation over generation.

Loci or the locus is a specific point where the allele for a specific trait lies on the chromosome. Species is the classification level of the taxonomy and includes organisms having major similar traits.

Therefore, option d is correct.

Learn more about the natural selection here:

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The best experimental setup to test the hypothesis that EMF causes CCD would be to have 3 hives exposed to high levels of EMF (experimental group) and 3 hives with no EMF exposure (control group). This setup allows for comparison and contrast between the two groups, thus enhancing the accuracy and validity of the test results.

The best experimental setup for testing your hypothesis that electromagnetic fields (EMF) cause Colony Collapse Disorder (CCD) in bees would be option C. 3 hives exposed to high levels of EMF and 3 hives with no EMF exposure. This arrangement allows for a control group (the hives with no EMF exposure), and an experimental group (the hives exposed to high levels of EMF).

The control group is necessary to compare and contrast with the experimental group, further enhancing the accuracy and validity of your results.

A good experiment requires a comparison between test subjects (the EMF exposed hives) and control subjects (the hives with no exposure), from which you can draw conclusions.

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Answer:

The answer is thymine.

Explanation:

RNA contains uracil but it does not contain thymine. DNA contains thymine. Both have adenine, cytosine, and guanine.

Answer:

Principles of Geology

Explanation:

J. Henslow gifted Darwin the first volume of Principles of Geology, written by Charles Lyell. The book explains about the old age of the earth. Accordingly, the slow rate of several geological processes suggests that the earth is very old.

Darwin read the book as the ship was crossing the Atlantic and learned about geological processes occurring over the millions of years. For example, he learned that the earth's surface was not formed by some catastrophic event.

In his book, Lyell explained the slow and gradual geological processes like erosion gave rise to the vast landscapes present on the earth's surface.

Darwin compared the time taken by geological processes to form the earth's surface and reasoned if these millions of years were enough to support the evolution of species.

Answer:

a. cells with more than one nucleus.

Explanation:

Mitosis is a cell division which completes in two stages. The first stage is called karyokinesis in which one nucleus divides into two and the second stage is called cytokinesis in which division of the cytoplasm takes place. During mitosis, cytokinesis is followed by karyokinesis. If a cell begins to divide and the division ceases after karyokinesis then the cell will have more then one nuclei in the absence of cytokinesis. Each of the  nuclei will have the same number of chromosomes.

A cell with more than one nucleus is called a multinucleated cell. For  example, human bone cell has many nuclei.  

When mitosis occurs without cytokinesis, it results in cells with more than one nucleus, as the physical separation of the newly formed nuclei into distinct cells does not occur.

In the cells of some organisms, when mitosis occurs without cytokinesis, it will result in cells with more than one nucleus. Mitosis is the process of cell division whereby the nucleus of the cell divides, producing two identical nuclei. Cytokinesis is the actual division of the cell into two parts, physically separating the two nuclei into distinct cells. If cytokinesis does not occur following mitosis, both nuclei will remain in the same cell, resulting in a cell with more than one nucleus.

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Answer:

Three treatments or reagents that causes protein denaturation are "heat", "urea" and "sodium hydroxide".

Explanation:

Heat: when a protein is exposed to elevated temperatures its molecules vibrate so rapidly and violently that its bonds are disrupted. This causes that the protein loses its tertiary and secondary structures and finally causes its denaturation.

Urea: a chemical denaturing agents that denatures proteins by lower the protein melting temperature which has a similar effect that high temperature. Urea compets for hydrogen bond donors and acceptors which affects the protein stability.

Sodium hydroxide: sodium hydroxide is an alkali agent that increases the pH value of the protein's solution. This results in removing hydrogen-bond contributing protons of the protein, which breaks its hydrogen bonds and causes its denaturation.

Answer:

Antigenic variation is the change occurs in antigenic property of the pathogen. In antigenic variation, a pathogen does changes in its surface protein or carbohydrate so that the immune system of the host is not able to recognize the pathogen.  

This antigenic variation is very much beneficial to pathogens because it gives advantage to the pathogen to infect the host again and again without being recognized by immune cells and to increase in number.

A recombination of avian and human influenza virus in a host like pig created a new version of the influenza virus which became very endemic worldwide is a classic example of antigenic shift. M. tuberculosis evades immune response by doing antigenic shift it's membrane and cause tuberculosis.

Antigenic variation is the process by which pathogens alter their surface antigens to evade the immune system. Pathogens like HIV and Borrelia burgdorferi demonstrate antigenic variation.

Antigenic variation is the process by which pathogens alter the surface antigens in order to evade recognition by the host's immune system. It allows pathogens to escape from the immune response and continue to infect the host.

An example of a pathogen that demonstrates antigenic variation is the human immunodeficiency virus (HIV). HIV mutates rapidly, leading to constantly changing proteins on its viral envelope. By the time the adaptive immune system responds, the virus's antigens have already changed.

Another example of a pathogen that undergoes antigenic variation is the bacterium Borrelia burgdorferi, which causes Lyme disease. The bacterium's surface lipoprotein, VlsE, undergoes genetic recombination, leading to antigenic variation. This allows B. burgdorferi to evade the host's immune defenses.

Answer:

The correct answer will be option-B.

Explanation:

Deoxyribose nucleic acid or DNA is the genetic material of the organism which is made up of nucleotide monomer. The structure of DNA is made up of two strands of nucleotides coiled in a helical structure thus providing a double-helical shape to the structure.  

Each nucleotide of a strand is composed of a five-carbon sugar, phosphate group and nitrogenous bases. These molecules are arranged in anti-parallel fashion in DNA which provides the polarity to the DNA strand. One strand is read from the 5' to 3' direction whereas another form 3'to 5' direction.

Thus, Option-B is the correct answer.

Answer:

The correct answer is option d. "India was a separate continent until 45 million years ago".

Explanation:

135 million years ago, Pangea was a single continent that became separated into Laurasia in the north and Gondwana in the south. India was part of Gondwana along with Australia, South America, Antarctica and Africa. However, as a result of tectonic activity India got separated from Gondwana. This period of time at which India was a separated continent is the factor that most likely explains why animals and plants in India differ greatly from species in nearby southeast Asia. At being a separated continent, India's plants and animals go through an independent evolutionary process which made them very different an unique from nearby species.

The difference in species between India and Southeast Asia is due to India being a separate continent until about 45 million years ago, leading to the evolution of distinct species through geographic isolation.

The most likely cause for the difference in animal and plant species between India and Southeast Asia is related to geographic isolation. Historically, India was indeed a separate continent until about 45 million years ago; this prolonged separation has allowed for the evolution of distinct species in India that differ from those in nearby Southeast Asia. This concept is fundamental to our understanding of biogeography and evolutionary theory, showcasing how geographic barriers can lead to speciation.

Regions such as Australia and India, which have been physically separated from other land masses for millions of years, are home to many endemic species — species that are found nowhere else on Earth. This is a result of species evolving in relative isolation, without the influence of gene flow from outside their geographic area, leading to unique biological diversity in these separated regions. Thus, the distinct animal and plant life in India compared to Southeast Asia can be attributed to the historical separation of India as a land mass.

Charles Darwin observed this phenomenon during his scientific expeditions, noting that geographically isolated areas with similar climates often had 'utterly dissimilar' flora and fauna, further providing evidence for speciation through geographic isolation.

The parent plants have genotypes RrYY.

In this question, we are given the numbers of yellow round seeds and yellow wrinkled seeds obtained from a cross between two pea plants. To determine the genotypes of the parent plants, we need to consider the dominant traits for seed shape (round) and seed color (yellow).

Let's assign the dominant traits as follows: Yellow (Y) is dominant to green (y), and round (R) is dominant to wrinkled (r).

Given that both parent plants produced yellow round seeds, we can conclude that their genotypes must be heterozygous for both traits: RrYY.

Answer:

A. Lipid A

Explanation:

The outer membrane of Gram-negative bacteria is present outside to the thin peptidoglycan layer. The outer membrane consists of lipopolysaccharide (LPS) which is the molecule having both carbohydrates and lipids.

The lipopolysaccharide has three parts out of which lipid A is the toxin one. Lipid A is embedded in the outer membrane through its fatty acids. When lipid A enters the blood stream of the host cell, it leads to septic shock. Lipid A is heat stable and highly toxic.

Answer:

Explanation:

A modern scientific inquiry system uses the scientific method to understand and explain the natural phenomenon.

The scientific theory involves various steps which begin with making an observation , asking questions, doing background research and proposing a hypothesis. The hypothesis is tested through experiments which prove or disproves the hypothesis which when established form laws and theory.

The Mendel followed the same approach unaware of the scientific method and performed experiments to answer the scientific question of how traits are controlled and passed on in generations.   He analysed the conclusions which were proved after his death by other scientists and framed the biological laws called Mendel's law of inheritance.

Thus, Mendel's inquiries followed the same steps of the scientific method.

Answer:

E. Fruits, vegetables, and high fiber grains

Explanation:

Prevention of cancer is the act of lowering the risk of getting the cancer .

Prevent cancer -

Maintaining a healthy lifestyle with proper eating habits , like consuming fruits vegetables and grains with high fiber , avoid the exposure of any carcinogenic substance , consumption of medicine and vaccines timely .

Exercise also plays a key role to maintain a fit and healthy body . Avoid direct sun , to protect the skin from harmful UVA and UVB radiations , hence sunscreen is mandatory on the daily basis .

To reduce the risk of cancer, it is recommended to eat a diet rich in fruits, vegetables, and high fiber grains. Hence, option E is correct.

Fruits and vegetables are rich in nutrients, antioxidants, and phytochemicals which may protect against or reduce oxidative damage to cells. Cruciferous vegetables, in particular, have been associated with a reduced risk of certain cancers. Foods rich in dietary fiber, such as whole grains and legumes, also play a role in decreasing the risk of colon cancer by promoting the rapid passage of materials through the colon and reducing the production of cancer-causing agents.

Maintaining a diet low in processed meats and red meats, avoiding excessive alcohol consumption, and emphasizing all types of fibers can further lower the risk of cancer.

Answer:

The correct answer will be option-A.

Explanation:

Recombineering is a molecular technique based on the recombination mechanism of DNA which is also known as recombination-mediated genetic engineering.

This method is used mainly in bacterial genetics to generate conditional mouse knockout target vector and modifying DNA in Bacterial artificial chromosome.

Since it does not use older methods like restriction enzymes and DNA ligases to combine DNA, therefore, option-A is the correct answer.

Answer:

Both aerobic and anaerobic respiration.

Explanation:

Glycolysis may be defined as the process of break down of glucose molecules for the formation pf ATP with the help of enzymes and chemical factors. Glycolysis occurs in the cytosol of the organism.

Glycolysis may occur in the presence of organism known as aerobic respiration. The glycolysis can occur in the absence of oxygen as well known as anaerobic respiration. The steps involved up to the formation of pyruvate molecule from the glucose is same in case of aerobic and anaerobic respiration.

Thus, the correct answer is option (c).

Answer:

A sequence of three nucleotide called triplet codon is the basic unit of the code relating DNA to protein because we have four nucleotide which can code for 20 amino acids. So if we take a doublet code it can code for only 16 combination (4²=16) which is not sufficient for 20 amino acids.

But when we take a triplet code it can code for 64(4³=64) combination which is sufficient to code 20 amino acids found in human body. So this was the reason for scientist to establish three nucleotide code for a single amino acids. Later it was found that genetic code is universal and in every organism it is same for a particular amino acid.

Answer:

b. A + G = C + T

Explanation:

Chargaff's rule states that a DNA molecule has the same amount of pyrimidines (T and C) as purines (A and G).

In the DNA, A pairs with T and G pairs with C. For that reason, the number of A bases has to be the same as the number of T bases, and the number of G has to be the same as the number of C.

Using the DNA base-pairing rules, the equation A + G = C + T would be consistent as the total number of purines (A and G) equals the total number of pyrimidines (C and T).

Within DNA, the base-pairing rules state that adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C). Based on these rules, the equation A + G = C + T would be consistent as the total number of purines (A and G) equals the total number of pyrimidines (C and T). The other options are incorrect because A does not equal G or C, and the sum of A and T does not necessarily equal the sum of G and C.

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Answer:

Steroids are prescribed to treat the condition of inadequate testosterone production, to treat the injury, and to initiate puberty. Some of the potential side effects of steroids are that in males it can cause reduction in sperm count, and shrinkage of testicles. While in women, it can cause the growth of body hair and can reduce the size of breasts.  

In both males and females, steroids can cause liver and kidney damage, acne, heart issue, and psychological issues.  

Diuretics help to reduce the amount of fluid in the blood vessels, which further helps to lower the blood pressure. Some of the side effects of diuretics are fatigue, muscle cramps, irregular heartbeat, dehydration, and even death.  

Creatine assists in making muscles to produce more ATP and delay muscle fatigue. Some of the side effects are stomach and muscle cramps, diarrhea, nausea, weight gain, and water retention.  

Stimulants help to reduce fatigue, better alertness and suppress appetite. Some of the side effects are nervousness, irritability, increased blood pressure, insomnia, hallucinations, and heart attack.  

Boron is used in the treatment of osteoarthritis, enhances the levels of testosterone, and for better muscle coordination and better-thinking skills. Some of the side effects of boron are diarrhea, dermatitis, discoloration of feces, vomiting, nausea, and upper abdominal pain.  

Vanadium is used to treat low blood sugar, diabetes, heart issue, high cholesterol, water retention, syphilis, and better athletic performance in weight training, and even prevents cancer. However, it can cause some side effects like green tongue, and diarrhea.  

There are various supplements each with potential benefits and side effects. Steroids increase muscle mass but can cause health problems; diuretics remove waters and salts in bodies but can dehydrate; creatine increases strength and muscle mass but can lead to stomach discomfort; stimulants enhance focus and reduce fatigue but can increase heart rate; Boron could boost testosterone levels but high doses are toxic; Vanadium could improve athletic performance, but could damage kidneys.

Several types of supplements are used for different purposes, each with potential benefits and side effects.

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Answer:b. Certain proteins are unique to each membrane.

Explanation:

Cell membranes of the eukaryotes are composed of proteins and lipids. The membranes of the eukaryotic cells are composed of lipid bilayers associated with the proteins. The proteins may differ in composition depending upon the type of cell. The membrane proteins act like a signal sequences to target other proteins to respective destinations to perform desired functions. Therefore, option B is correct.

Proteins vary amongst different membranes in a eukaryotic cell, as they are specifically distributed to carry out specialized functions related to their respective location within the cell.

The membranes of a eukaryotic cell can vary in several ways, but the most accurate answer to your question would be option b: 'Certain proteins are unique to each membrane'. This is because, although all membranes contain phospholipids and are amphipathic, different proteins are embedded within these phospholipid layers based on the specific functions they serve in different parts of the cell, allowing them to carry out specialized tasks. These can range from transport proteins in the cell membrane that regulate the passage of substances, to proteins in the mitochondrial membrane involved in energy production. Therefore, the variation in proteins is what truly distinguishes different cellular membranes within a eukaryotic cell.

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Answer:

Taq DNA polymerase is an enzyme which can withstand the high temperature as it is resistance to heat therefore is heat stable. This enzyme plays an important role in Polymerase chain reaction as a procedure requires high temperature.

The enzyme was originally isolated from a thermophilic bacterium named Thermus aquaticus near the Lower Geyser Basin of Yellowstone National Park. The Taq word was adapted from the name of the bacteria as Thermus aquaticus = Taq and polymerase as it poylmerizes the DNA.

Taq DNA polymerase derived its name from the thermophilic bacterium Thermus aquaticus, wherein it was first isolated. The enzyme is crucial in the Polymerase Chain Reaction (PCR) process due to its ability to withstand high temperatures. It plays a key role in DNA replication by adding nucleotides to the growing DNA chain.

The enzyme Taq DNA polymerase got its name from the bacterium it was derived from, thermophilic bacterium Thermus aquaticus, which was isolated from a hot spring in Yellowstone National Park. The prefix 'Taq' is a shorthand reference to Thermus aquaticus.

In the Polymerase Chain Reaction (PCR), a procedure commonly used in molecular biology to replicate a specific DNA sequence, Taq DNA polymerase plays a crucial role. Due to its stability at high temperatures, it can withstand the heat used in PCR. This quality enables it to construct new strands of DNA based on the templates, providing new copies of the desired sequence.

DNA polymerase in general, is an enzyme that adds nucleotides to the growing DNA chain during the process of DNA replication. This process requires energy which the enzyme obtains from nucleotides that have three phosphates attached to them.

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Answer:

a. fatty acids is the correct answer.

Explanation:

fatty acids is NON-polar molecule.

Nonpolar molecules are that molecules which are not soluble in water and fatty acids are not soluble in water.

fatty acids are hydrophobic and the hydrocarbon chain present in fatty acids are nonpolar, thus that's the reason fatty acid is nonpolar.

examples of fatty acids