The correct answer is E. A cell
Explanation:
The cell is the smallest unit of life that exists and that constitutes all living organisms and body tissues including unicellular and multicellular organisms. Due to this, cells are considered as the fundamental unit of life as even the smallest and simplest living organisms are made of cells or at least made of one cell.
Cells are commonly made up of three main parts: the cell membrane which surrounds the cell and controls the substances that enter and leave it; the nucleus which is the structure within the cell that contains the nucleolus and most of the cell's DNA; and the cytoplasm that is the fluid inside the cell that contains other tiny cell particles with specific functions, such as the Golgi apparatus, mitochondria, and the endoplasmic reticulum. This applies to all cells except to prokaryotic cells because these do not contain a nucleus but a chromosome in the middle of the cell.
The control for a complementation test, which is often omitted, is the:
a. trans test
b. cis test
c. complementation hybrid
d. citron test
e. cis-trans test
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.
A microbiologist obtained two pure biological samples: one of a virus, and the other of a viroid. Unfortunately, the labels had been lost. The microbiologist felt she could distinguish the two by analyzing for the presence or absence of a single molecule. What molecule would she search for and why?
The researcher could look for the presence of proteins, because viruses have a envelope (capsid) composed of proteins that involve their genetic material. The capsid may have a helical or icosahedral structure and is extremely regular. Viroids cannot synthesize any type of protein, so differentiation is possible.
The microbiologist should look for the presence of protein to distinguish between the virus and the viroid, as only the virus will contain a protein coat.
Explanation:The molecule the microbiologist should search for to distinguish between a virus and a viroid is protein. Viruses have a protein coat known as a capsid that encloses their nucleic acid core, which can be either DNA or RNA. Viroids, on the other hand, consist solely of a short strand of circular, single-stranded RNA without a protein coat. By analyzing the samples for the presence of protein, she can determine which is the virus (which has protein) and which is the viroid (which lacks protein).
Although none are represented in the web diagram, mollusks are eaten by raccoons. Freshwater mussels are filter feeders. If the mussel population were decreased by a lengthy period of dry conditions, which organisms population would decrease?
"The correct answer is the raccoons' population would decrease.
To understand the impact of a decreased mussel population on the ecosystem, one must consider the food web dynamics. Mussels are a food source for raccoons; therefore, if the mussel population were to decrease due to prolonged dry conditions, the raccoons would have less food available to them. This scarcity of food would likely lead to a decrease in the raccoon population due to starvation, reduced reproductive success, or the need to find alternative food sources which might not be as nutritious or abundant.
Freshwater mussels are filter feeders, which means they play a crucial role in their aquatic habitats by filtering water and removing pollutants, thereby maintaining water quality. A significant decrease in the mussel population could lead to deteriorating water quality, which might affect other aquatic organisms as well. However, the direct impact of the mussel population decline, as per the information provided, would be most immediately felt by their predators, in this case, the raccoons.
It is important to note that in a complex ecosystem, the effects of a population decline can be far-reaching and can affect multiple trophic levels. However, based on the information given and the direct predator-prey relationship mentioned, the population that would decrease as a result of the mussels' decline would be the raccoons."
Tropism describes a virus’s affinity for specific tissues:
A) True
B) False
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.
Differential medium can separate Gram negative bacteria from
Grampositive bacteria.
True or False?
Answer: True. Selective media can be used to separate gram negative from gram positive bacteria.
Explanation: Selective media allow certain types of organisms to grow, and inhibit the growth of other organisms.
For example: Media containing potassium tellurite will inhibit the growth of gram negative bacteria while media supplemented with penicillin will inhibit the growth of gram positive bacteria.
What might be one reason for not finding any cells when you examine a slider under the microscope?
Answer:
Well, there can be various causes of not finding any cells while examining a slider under the microscope. Some of them are as follows:
a. The light of the microscope might be switched off and the slide does not comprise any cells.
b. The microscope is not focused appropriately so that one can witness the cells.
c. The region of the slide comprising the cells is not coming in the field of vision.
d. The magnification of the microscope is not appropriate, that is, either it is very low or is very high.
e. Destruction of the sample would have taken place.
A fatty with the maximum nimber of hydrogen atoms possile is unsatured; is that true?
Answer:
False.
Explanation:
Fatty acids may be defined as the carboxylic acid that contains the terminal carboxyl group and the hydrocarbon chain. Two types of fatty acid are saturated fatty acids and unsaturated fatty acids.
The unsaturated fatty acids contains double or triple bond in the fatty acids. The hydrogen are removed from the hydrocarbon chain and introduces double and triple bond in the fatty acids. A fatty acid with maximum number of hydrogen atom is saturated.
Thus, the answer is false.
Which process in eukaryotic cells will normally proceed whether O2 is present or absent?
A) electron transport
B) glycolysis
C) the Krebs cycle
D) oxidative phosphorylation
E) fermentation
Answer:
b) glycolisis
Explanation:
Glycolisis precedes the Krebs cycle and can take place under aerobic or anaerobic conditions. Under aerobic condition, energy is directed towards the Krebs cycle in the form of piruvate and NADH to create more ATP. Under anaerobic conditions piruvate does not enter the Krebs cycle and it is oxidized to produce lactate.
A cross between two pea plants, both of which grew from yellow round seeds, gave the following numbers of seeds: 156 yellow round and 54 yellow wrinkled. What are the genotypes of the parent plants? (Yellow and round are dominant traits.)
The parent plants have genotypes RrYY.
Explanation: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.
Which type(s) of cell division (mitosis, meiosis l, meiosis Il) reduce(s) the chromosome number by half? Which type(s) of cell division can be classified as reductional? Which type(s) of cell division can be classified as equational?
Answer:
Which type(s) of cell division reduce(s) the chromosome number by half?
Meiosis l
Which type(s) of cell division can be classified as reductional?
Meiosis I
Which type(s) of cell division can be classified as equational?
Mitosis and Meiosis II
Explanation:
Meiosis is a type of cell division which occurs in the germ or reproductive cells to produce gametes. It is completed in the two stages, meiosis I and meiosis II. The cells which are going to divide by meiosis are diploid having two sets of chromosomes. Meiosis I is the first stage of the meiosis. At the end of meiosis I two daughter cells are formed having only 1 set of chromosomes and chromosome numbers are reduced to half. Thus, meiosis I is a reductional division.
Mitosis and meiosis II is the equational division as after division chromosome number remains the same as in the parent.
An intrinsic value biodiversity stems form religious, moral, or either obligations to preserce the worl's species.
a. True
b. False
Answer:
a. True
Explanation:
As the word biodiversity itself is the diversity of plant and animal life keeping in mind that ecological biodiversity. This being an inherited value and must be protected as every citizen of the country has a moral obligation and duty toward the laws of land and protection of the biotic wealth of the nation. Apart from this biodiversity also has a genetic, social and economic value along with the cultural and spiritual aspects this biodiversity has scientific and educational significance. Various obligations on the part of the state government to word the protection of the species from any kind of changes in the ecological cycles, like protection of biosphere and give value to this genetic makeup that provides fuel and energy to the planet.The lipopolysaccharide (LPS) possessed by Gram-negative bacteria contributes to the virulence and pathogenic potential of these organisms. The toxic portion of the LPS in ___________.
a. lipid A
b. located in the plasma membrane
c. a protein secreted by the bacterium
d. an antigenic polysaccharide
e. all of the above
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.
There is antibody-mediated and cell-mediated specific immunity. Which type of cells are primarily involved in the antibody-mediated immune response?
A. Macrophages
B. B cells
C. Complement proteins
D. T cells
E. Antigens
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.
The native structure of proteins has only marginal
thermodynamicstability.
Describe (3) treatments or reagents which denature proteins.
Howdoes each work?
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.
The hypothalamus is our brain's appetite control center.
a. True
b. False
Answer:
A
Explanation:
Hunger, fullness, and energy balanced are regulated by the hypothalamus. Hunger and fullness signals, in the form of hormones, travel through the bloodstream from tissues that consume energy to the brain. The hypothalamus is the region where these neuronal and hormonal signals integrate. After the reception of this signals the hypothalamus orchestrates a signaling cascade containing other hormones to create the hunger sensation.
What are vasodilation? Vasoconstriction?
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.
Explanation: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.
Learn more about Vasodilation and Vasoconstriction here:https://brainly.com/question/13258282
#SPJ3
Individuals who are allergic to penicillin generate _______ antibody against the antibiotic.
a. IgM
b. IgG
c. IgA
d. IgE
e. IgD
Answer:
d. IgE
Explanation:
Immunoglobulin E (IgE) are antibodies that respond to allergic reactions. The response leads to the release of the anti-inflammatory histamine and vasoactive chemicals.
why are uncompetitive andmixed inhibitors generally considered to
be more effective in vivothan competitive inhibitors?
Answer:
The uncompetitive and mixed inhibitors are not affected by the substrate concentration while inhibition by a competitive inhibitor can be overcome by increasing the concentration of the substrate.
Explanation:
A competitive inhibitor competes with the substrate for the active site of the enzyme. When the competitive inhibitor combines with the enzyme and forms the enzyme-inhibitor complex (EI complex), the substrate cannot bind to the active site. However, the inhibition by competitive inhibitor can be overcome by increasing the substrate concentration around the enzyme which in turn would allow the substrate to bind to the active site and the reaction would proceed.
On the other hand, an uncompetitive inhibitor binds to the site at the enzyme different from the active site. Once the ES complex is formed, the uncompetitive inhibitor joins the complex to inhibit the enzymatic activity.
Likewise, a mixed inhibitor also occupies a site on the enzyme distinct from the active site for the substrate. A mixed inhibitor binds to the enzyme or ES complex to inhibit the reaction.
Since the binding site for uncompetitive and mixed inhibitors are distinct from the substrate-binding site on the enzyme, increasing the substrate concentration can not overcome the inhibition.
In the cells of some organisms, mitosis occurs without cytokinesis. This will result in
a. cells with more than one nucleus.
b. cells that are unusually small.
c. cells lacking nuclei.
d. cell cycles lacking an S phase
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.
Explanation: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.
Learn more about Mitosis and Cytokinesis here:https://brainly.com/question/1995803
#SPJ3
A change in DNA resulting in an incorrect protein is the problem in sickle cell disease. Is this normally the problem in genetic diseases?
A. Yes, the DNA may be "correct" but can produce abnormal proteins which cause disease.
B. No. In other genetic diseases, the proteins are all correctly made, but then they damage the DNA.
C. No. Most genetic diseases result from errors in cell division.
D. Yes, abnormal proteins created by abnormal DNA is the problem in all genetic diseases.
E. It's not clear what the problem is in most genetic diseases.
Answer:
D. Yes, abnormal proteins created by abnormal DNA is the problem in all genetic diseases.
Explanation:
DNA carries the information for the correct development and function of the human body. A gene is defined as a DNA fragment that codifies for a protein, this means that genes carry the information to shape a protein in the ribosomes. If the information is "corrupted" proteins can still be formed but can't work correctly.
Where is ATP synthase located in the mitochondrion?
A) ribosomes
B) cytochrome system
C) outer membrane
D) inner membrane
E) matrix
Answer:
D) inner membrane is the correct answer.
Explanation:
ATP synthase located in the inner membrane of the mitochondrion.
ATP synthase has two subunits knowns as rotating subunit
FO F1that support in the ATP generation by oxidative phosphorylation.
ATP synthase is an enzyme that produces adenosine triphosphate Which is called an Energy molecule.
ATP function is to provide energy to the cells.
ATP synthase is located in the inner membrane of the mitochondrion, which has folds called cristae to increase surface area for ATP synthesis.
Explanation:The location of ATP synthase in the mitochondrion is within the inner membrane. This enzyme is crucial for the production of ATP (adenosine triphosphate), the cell's primary energy currency. The inner membrane of the mitochondrion contains folds called cristae, which increase its surface area and are integral to the function of the electron transport chain where ATP synthesis takes place. Therefore, the correct answer is D) inner membrane.
Which of the following best demonstrates the unity among all organisms?
a. emergent properties
b. descent with modifications
c. the structure and function of DNA
d. natural selection
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.
Explanation: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.
Learn more about DNA here:https://brainly.com/question/34857740
#SPJ3
One of the following is NON-polar molecule
a. fatty acids
b. glucose
c. protein
d. oxygen
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
fatscholesterolsoilssteroidsIn what way do the membranes of a eukaryotic cell vary?
a. Phospholipids are found only in certain membranes.
b. Certain proteins are unique to each membrane.
c. Only certain membranes of the cell are selectively permeable.
d. Only certain membranes are constructed from amphipathic molecules
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.
Explanation: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.
Learn more about Eukaryotic Cell Membrane Variations here:https://brainly.com/question/32921743
Calculate the surface-to-volume ratio of a spherical cell 15mum in diameter and of a cell 2mum in diameter. What are the consequences of these differences in surface-to-volume ratio for cell functions?
Answer:
For calculating the surface to volume ratio for a spherical cell,
Surface area (S) = 4πr²
Volume (V) = 4πr³ / 3
Ratio = S / V = 4πr² / 4πr³ / 3 = 3 × 4πr² / 4πr³
= 3/r
1. 15 micrometer diameter = Ratio = 3/7.5 = 0.4
2. 2 micrometer diameter = Ratio = 3/1 = 3
The cells exhibiting high surface to volume ratio shows enhanced metabolic activity. Shows easy uptake of oxygen, nutrients, water, and also the excretion of waste as they possess large surface.
Final answer:
The surface-to-volume ratio for a cell with a 15 μm diameter is approximately 0.4:1, while the ratio for a 2 μm diameter cell is roughly 3:1. This difference implies that smaller cells have a higher efficiency for substance exchange due to a more favorable surface area relative to volume. Large cells may face limitations in diffusion, potentially leading to cell division or death if the cell cannot maintain sufficient exchange with its environment.
Explanation:
To calculate the surface-to-volume ratio of spherical cells, we use the formulas for the surface area (SA) and the volume (V) of a sphere. The surface area of a sphere is 4πr² and the volume is (4/3)πr³, with r being the radius of the sphere. For a cell with a diameter of 15 μm (radius = 7.5 μm) and a cell with a diameter of 2 μm (radius = 1 μm), we calculate as follows:
Surface-to-volume ratio for 15 μm diameter cell:
SA = 4π(7.5)2 ≈ 706.86 μm²
V = (4/3)π(7.5)3 ≈ 1767.15 μm³
Surface-to-volume ratio = SA/V ≈ 0.4:1
Surface-to-volume ratio for 2 μm diameter cell:
SA = 4π(1)2 ≈ 12.57 μm²
V = (4/3)π(1)3 ≈ 4.19 μm³
Surface-to-volume ratio = SA/V ≈ 3:1
Differences in surface-to-volume ratios have significant consequences for cell functions. A higher ratio means the cell has more surface area relative to its volume, which is advantageous for the diffusion of substances in and out of the cell. Smaller cells, with their higher surface-to-volume ratios, can therefore absorb nutrients and expel waste more efficiently than larger cells. However, as cells grow, their volume increases faster than their surface area, leading to a decreased surface-to-volume ratio, which can limit their ability to exchange materials and may trigger cell division or result in cell death if the cell becomes too large to maintain adequate exchange with the environment.
Match each type of heat transfer with the example describing it
(1) Conduction
(2) Free Convection
(3) Forced Convection
(4) Evaporation
(5) Radiation
Possible Answers:
(A) A bear stands in a cold flowing stream and loses heat to the water.
(B) A seagull stands on ice and loses heat through its feet.
(C) A lizard absorbs heat from the sun's rays.
(D) An athlete sweats while running a race.
(E) A dog stands outside on a cold, but windless, day and loses heat to the air.
Answer:
(1) Conduction - (B) A seagull stands on ice and loses heat through its feet.
heat is lost due to direct contact.
(2) Free Convection - (E) A dog stands outside on a cold, but windless, day and loses heat to the air. There is heat transfer due to difference in temperatures.
(3) Forced Convection- (A) A bear stands in a cold flowing stream and loses heat to the water. Here we consider buoyancy effects.
(4) Evaporation- An athlete sweats while running a race. water turns evaporates from the body taking a away heat.
(5) Radiation - (C) A lizard absorbs heat from the sun's rays. Sun´s heat travels as radiation.
Explanation:
Final answer:
The types of heat transfer are matched with their examples: (1) Conduction with (B) a seagull on ice, (2) Free Convection with (E) a dog losing heat to air, (3) Forced Convection with (A) a bear in flowing water, (4) Evaporation with (D) an athlete sweating, and (5) Radiation with (C) a lizard in sunlight.
Explanation:
The student has asked to match each type of heat transfer with the corresponding example. Here are the matches:
(1) Conduction: (B) A seagull stands on ice and loses heat through its feet.
(2) Free Convection: (E) A dog stands outside on a cold, but windless, day and loses heat to the air.
(3) Forced Convection: (A) A bear stands in a cold flowing stream and loses heat to the water.
(4) Evaporation: (D) An athlete sweats while running a race.
(5) Radiation: (C) A lizard absorbs heat from the sun's rays.
Each mechanism can be better understood by these everyday examples:
Conduction occurs when heat is transferred through direct contact, such as when you touch a hot stove.
Convection involves the movement of heat through a fluid (gas or liquid), like when warm air circulates in a room.
Evaporation is the process of a liquid turning into a vapor, taking heat away, like when wet clothes dry on a line.
Radiation involves the transfer of heat in the form of electromagnetic waves, such as sunlight warming your skin.
Discuss the concept of the null hypothesis and its use in data analysis.
Answer:
Null hypothesis may be defined as the any type of assumption in which the observed difference between two sample in the statistical population is accidental. Null hypothesis is used in the field of genetics as well.
If one accepts the null hypothesis this means that there is no significant differences between the observed values and the expected values of the experiment. The rejection of null hypothesis explains that there may be significant difference between the expected value and observed value.
Barred feather pattern is a Z-linked dominant trait in chickens. What offspring would you expect from (a) the cross of a barred hen to a non-barred rooster? (b) the cross of an Fl rooster from part (a) to one of his sisters?
Answer:
Let the "barred" allele be caller B and the "non-white" allele b. Since chickens use chromosomes [tex]Z[/tex] and [tex]W[/tex] to determine sex, hens would have chromosomes [tex]ZW[/tex], and roosters would have chromosomes [tex]ZZ[/tex]. A Z-linked gene is represented as a superscript on the [tex]Z[/tex] chromosome, [tex]Z^{B}[/tex] for the dominant allele and [tex]Z^{b}[/tex] for the ressesive allele.
A barred hen would have a copy of B on its Z chromosome, a non-barred rooster would have both copies of b on both Z chromosomes. Using Punnet squares to represent the crosses we get the following cases:
[tex]\begin{center}\begin{tabular}{ |c|c|c|c| }\ & Z^{B} & W \\ \ Z^{b} & Z^{B}Z^{b} & Z^{b}W \\ \ Z^{b} & Z^{B}Z^{b} & Z^{b}W \\ \end{tabular}\end{center}[/tex]
That is a ratio of two barred heterozygote roosters to two non-barred hens. Crossing them we get:
[tex]\begin{center}\begin{tabular}{ |c|c|c|c| }\ & Z^{b} & W \\ \ Z^{B} & Z^{B}Z^{b} & Z^{B}W \\ \ Z^{b} & Z^{b}Z^{b} & Z^{b}W \\ \end{tabular}\end{center}[/tex]
That is a ratio of one barred heterozygote rooster to one barred hen to one non-barred rooster to one non barred hen.
For part a) crossing barred hen with non-barred rooster produces 50% barred and 50% non-barred offspring of both genders. In part b) cross between their barred F1 offspring will again result in a mix of barred and non-barred offspring.
The barred feather pattern in chickens is a Z-linked dominant trait. In chickens, males have ZZ sex chromosomes, and females have ZW sex chromosomes.
(a) Cross of a barred hen (ZW) to a non-barred rooster (ZZ)
The barred hen has genotype [tex]Z^BW[/tex], and the non-barred rooster has genotype ZZ. The offspring will be:
50% barred males ([tex]Z^BW[/tex])50% non-barred males (ZZ)50% barred females ([tex]Z^BW[/tex])50% non-barred females (ZW)(b) Cross of an F1 barred rooster ([tex]Z^BW[/tex]) to one of his barred sisters ([tex]Z^BW[/tex]) Since they both possess the barred trait, their genotypes are [tex]Z^BZ[/tex] and ([tex]Z^BW[/tex]), respectively. The offspring from this cross will be:
25% barred males [tex](Z^BZ^B)[/tex]25% non-barred males (ZZ)25% barred females [tex](Z^BW)[/tex]25% non-barred females (ZW)What is antigenic variation and how is it beneficial to pathogens? Give an example of two pathogens that demonstrate antigenic variation.
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.
Explanation: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.
Which of the following bases is used in RNA but not DNA?
a. adenine
b. thymine
c. uracil
d. guanine
Answer:
The answer is thymine.
Explanation:
RNA contains uracil but it does not contain thymine. DNA contains thymine. Both have adenine, cytosine, and guanine.