Answer:
a) A..........B
Explanation:
Crossing over is the process that occurs during the pachytene stage of prophase-I of meiosis-I. During crossing over, two chromatids of a homologous pair of chromosomes exchange genetic material between themselves. It results in the production of new allele combinations on the chromatids. The process of crossing over mostly occurs between the alleles of two or more genes that are present far apart from each other on the same chromosome.
Among the given option, the arrangement of alleles in option A has the maximum distance between the alleles A and B. This increases the probability of crossing over between these two alleles. The alleles of genes present close together on a chromosome are least likely to undergo crossing over.
Answer:
Option D and E , AB............. and ..........AB
Explanation:
When the alleles are located far away from each other on the same chromosomes they remain unlinked and hence assort independently. On the other hand alleles which are lying close to each other on the same chromosomes are inherited as a single unit or are inherited together; therefore they are called as linked allele pair. Crossing occurs when the two chromosomes exchange their genetic material. When two genes lie very close to each other, there are very rare chances of them getting separated by crossing over.
Hence, option D and E are correct
Many studies have indicated that there is some genetic influence on body weight and composition. Researchers have established a variety of theories that attempt to explain why some individuals gain weight more easily than others and why weight can be so difficult to change long-term. Choose the correct statement about theories regarding genetic influence on weight status.
a. The thrifty gene theory suggests that some individuals have a "thrifty metabolism," which could help a person survive when food is scarce.
b. According to recent research, the FTO gene may increase feelings of satiety.
c. The set point theory indicates that bodies are meant to stay within a narrow weight range, which cannot be changed long-term.
d. Drastically reducing calorie intake causes BMR to increase, which helps individuals deviate from their "set point" for weight
Answer:
A
Explanation:
The thrifty gene hypothesis postulates that due to dietary scarcity during human evolution, people are prone to obesity by storing energy as fat, an ability to take advantage of rare periods of abundance and this is advantageous during times of food availability. individuals with greater adipose reserves would more likely survive famine. This tendency to store fat could lead to obesity.
FTO is an enzyme that is encoded in humans by FTO gene located on chromosome 16. Increase in this enzyme is associated with the regulation of energy intake but not feeding reward. Also, the set point theory indicates that bodies are meant to stay within a narrow weight range but it is susceptible to chnage overtime.
Water is essential for survival. It is important to understand the factors that affect water balance and the best sources to help an individual meet daily water requirements.
Select all the sentences below that correctly describe water.
Select all that apply.
1-Sweating during exercise is considered insensible water loss.
2-Water helps maintain body temperature.
3-Diuretics like alcohol and some medications can cause the body to lose water.
4-Caffeinated drinks like coffee or tea cannot count toward an individual’s daily fluid needs.
5-Foods like bread or crackers do not contribute to total water intake
Answer:
2-Water helps maintain body temperature.
3-Diuretics like alcohol and some medications can cause the body to lose water.
Explanation:
Dehydration occurs when the amount of what loss is more than the amount taken. And we lose water in many ways therefore taking water on a regular basis is important to replace the fluids lost and keep the body functioning.
Water Maintains the Body Temperature
During high temperature, the body cools itself naturally by sweating and by sweating a large amount of water is lost. So when enough water is not taken, there will be less production of sweating thereby causing the body's temperature to rise.
Alcohol Causes Water Loss
Taking excess alcohol can result to dehydration because the hormone called anti-diuretic (while alcohol is diuretic) is used to reabsorb water by the body and alcohol in the body depletes the production of this hormone. The body loses more water than normal with a reduced amount of anti-diuretic in the body. Excessive intake of alcohol can also cause vomiting, which depletes the body of fluids and can cause further dehydration.
The statement that describes water as an essential for survival and the factors that affects its balance in our body and as a best source in meeting daily target are:
2-Water helps maintain body temperature.
3-Diuretics like alcohol and some medications can cause the body to lose water.
Water can be regarded as the best substance that can keep our body hydrated. Water helps in maintaining our Body Temperature, when our temperature is high, we loose water through sweating and our body becomes cool.However we do loose some water during rigorous exercise as well as other human activities which is considered Dehydration.Diuretics such alcohol can make our body to become dehydrated because drinking of alcohol usually limit the production of anti-diuretic hormones in our body.Therefore, option 2 and 3 are correct.
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1. What information/structures were you able to glean from the Gram stain that you could not get from the methylene blue stain?
2. What information/structures were you able to glean from the methylene blue stain that you could not get from the Gram stain?
3. Is Saccharomyces cerevisiae Gram-positive or Gram-negative?
4. Research and describe the composition of yeast cell walls. How does the composition compare to the cell walls of Gram-positive or Gram-negative bacteria?
Answer 1: Gram staining can stain the outer structure of cell such as cell wall and cell membrane. This stain used to identify the gram positive and gram negative cell in a cluster of bacterial colony. These structure can not be stained by using methylene blue.
Answer 2: Methylene blue stain used to stain the internal structures of the cell including DNA in nucleus and RNA fractions in cytoplasm. These structures can not be stained and identified using gram staining.
Answer 3: A research paper (J. gen. Microbiol. (1963), 30, 223-235) stated that Saccharomyces cerevisiae is a gram positive bacteria.
Answer 4: A research paper (The Chemical Composition and Structure of the Yeast Cell Wall) provided the actual and true composition of yeast cell wall. According to this paper, yeast cell wall is composed of protein ( 13%), lipids (8.5%), and Polymaccharides (78%). While on the other hand cell wall of gram positive bacteria is composed of peptidogylcane (50-60%), lipids (1-4%), teichoic acid and lipoteichoic acid. Further, cell wall of gram negative bacteria composed of lipopolysacharides, lipoproteins, peptidoglycane and lipids (11-12%).
A student is performing a Gram stain of a mixed culture of both E. coli and S. aureus and he forgets to decolorize with ethanol. What should his slide look like? A. Both are colorless because the ethanol is needed for the cells to absorb the stains B. The E.coli should appear red/pink and the S aureus should appear blue/purple. C. Both the E. coliand the S. aureus should appear blue/purple. D. Both the E. coliand the S. aureus should appear red/pink.
Answer:
Correct option is C.
Explanation:
Gram staining is a technique of separation of the bacteria based on the cell wall composition. Steps involved in gram staining are:
1) Primary stain application which is known as crystal voilet, it stains all cells purple/blue.
2) Mordant stain application which is known as iodine solution, is added, and form crystal iodine complex, all cells continue to stain blue/purple.
3) Decoloration step, in this step, we can differentiate gram negative or gram positive bacteria. So, decolorizing agent such as ethanol or acetone extracts blue color from thin walled peptidoglycan layer gram negative bacteria, and gram positive bacteria remain blue/purple because it contains thick walled peptidoglycan layer.
4) Counterstain application in this step safranin red dye stain the gram negative decolorized cells red/pink, and gram positive bacteria remain same blue.
So, if a student is performing a Gram stain of a mixed culture of both E. coli and S. aureus, and he forgets to decolorize with ethanol Both the bacteria should appear blue/purple color.
DNA polymerase has multiple mechanisms for editing and error correction, whereas the capacity for error correction in RNA polymerases seems to be quite limited. However, like a DNA mutation, an RNA polymerase error in transcription can cause production of a mutated protein. The limited error correction of RNA polymerase seems to be inconsistent with the potentially serious consequence of producing a protein with an altered amino acid sequence.A) Defective proteins are often degraded quickly, making their effects temporary. B) Single amino acid substitutions caused by errors in mRNA transcription would not affect protein function. C) Unlike DNA mutations, mRNA transcripts have short half-lives and are not inherited across many generations.D) Degradation of defective proteins activates mRNA repair pathways E) RNA polymerases synthesize many transcripts per gene, so only a small fraction of RNA transcripts would have errors. F) ch mRNA molecule is only translated once and then degraded.
Answer: D) Degradation of defective proteins activates mRNA repair pathways
Explanation:
A recent publication (J Phys Condens Matter. 2013. 18;25(37):374104.) provided the information on this matter. According to researcher RNA polymerase have ability to backtrack and translocate the error on both RNA transcript and DNA template. By doing so RNA polymerase cleave the defective part on RNA transcriptome by the process called proofreading. While proofreading contribute in accuracy of transcription but on contrary it also slower the process of transcription.
DNA polymerase possesses robust error correction mechanisms while RNA polymerase's error correction is limited. However, while errors from both can result in defective proteins, the DNA mutation is permanent and inheritable unlike the temporary and non-inheritable effects of RNA polymerase errors.
Explanation:True, DNA polymerase possesses multiple mechanisms for editing and error correction, ensuring the high accuracy of DNA replication. Mistakes can occur, but repair mechanisms often promptly correct these errors. If an error is not corrected, it leads to a mutation which is serious because DNA mutations are permanent and transmitted to successive generations. This is different from RNA polymerase, which has a limited error correction capacity.
Unlike a DNA mutation, if an error in transcription by RNA polymerase occurs, it can lead to the production of a defective protein. However, these defective proteins are often short-lived as the mRNA transcripts have short half-lives and degrade quickly. Additionally, each mRNA molecule is usually translated only once before degradation. Therefore, the effects of RNA polymerase errors are temporary and not inherited across generations, unlike DNA mutations.
Lastly, while both DNA and RNA polymerase mechanisms can lead to the production of defective proteins, the extent and duration of their effects differ significantly because of the inherent differences in DNA and RNA stability and the mechanisms of their polymerases.
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Select ALL of the following that are directly used to control fatty acid oxidation in cells.
A. negative feedback regulation if free fatty acids accumulate
B. changing the activity of the acylcarnitine shuttle
C. targeting the acetyl-CoA transport shuttle in the mitochondrial membrane
D. altering the activity of the oxidoreductase enzymes in β-oxidation
Answer:
The correct statements are A negative feed back regulation if free fatty acid accumulate C targeting the acetyl CoA transport shuttle in the mitochondrial membrane
Explanation:
The beta oxidation of fatty acid can be regulated by several following ways.
A The accumulation of free fatty acids exerts negative feedback during beta oxidation of fatty acids.As oxidation of fatty acids result in the breakdown of complex fatty acids in free fatty acids and acetyl CoA,the accumulation of free fatty acids lowers the rate of beta oxidation of fatty acid.
C The targeting of end product of beta oxidation that is acetyl CoA to the mitochondrial membrane also regulates the beta oxidation pathway.Because more the transport of acetyl CoA to the mitochondrial membrane more will be the rate of fatty acid break down by beta oxidation.
Of the following, which is the most current description of a gene? Of the following, which is the most current description of a gene? a unit of heredity that causes formation of a phenotypic characteristic a DNA sequence that is expressed to form a functional product: either RNA or polypeptide a DNARNA sequence combination that results in an enzymatic product a DNA subunit that codes for a single complete protein a discrete unit of hereditary information that consists of a sequence of amino acids
Answer:
a unit of heredity that causes formation a phenotypic characteristics
A gene is described as a unit of heredity that causes the formation of a phenotypic characteristic. Therefore, option A is correct.
What are genes and their function?Genes are segments of DNA that hold the instructions needed to create a single, usually protein-producing, molecule in your body. These proteins regulate how our body develops and functions; they are also in charge of determining many of our physical traits, like our eye color, blood type, and height.
In the chromosomes, genes that code for a specific character's assigned expression is present in a linear order. They transfer from one generation to another.
Thus, a gene is described as a unit of heredity that causes the formation of a phenotypic characteristic. Therefore, option A is correct.
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In the metabolism of fats, the fatty acids enter the reactions of the _________.
Answer: cytosol
Explanation:
Fatty acid metabolism is also known as fat oxidation. The fatty acid to be metabolized e.g Stearic acid enters the reactions of the CYTOSOL of the cell to become ACTIVATED, then it forms Stearyl-CoA.
The Stearyl-CoA then is transported to the cell mitochondria where it is reduced sequentially in form of units of acetyl-CoA until oxidation is completed
Base your answer to the following question on the statement below and on your knowledge of biology. Some internal environmental factors may interfere with the ability of an enzyme to function efficiently. Identify two internal environmental factors that directly influence the rate of enzyme action.
Answer:
Temperature & Presence of any inhibitors or activators.
Explanation:
Temperature: Although a higher temperature increases the rate of reaction, enzymes denature after a specific temperature. At different temperatures, the different enzyme works. So, for getting a particular function from an enzyme, proper temperature is needed. If adequate temperature won't present or temperature will fluctuate, the enzyme won't be able to work effectively.
Presence of any inhibitors or activators: When any inhibitors will present during an enzymatic reaction, the enzyme won't be able to work effectively. And if any activators will present, it will completely change the work efficiency of any enzyme.
The retina of the eye extends anteriorly only to a wavy line called the;
a. fovea centralisb. conjunctivac. uvead. ora serrata
Answer: Option D.. ora serrata.
Explanation: The serrated or wavy junction which lies between the ciliary body and the retina is called the orange serrata.
The simple non photosensitive area of the ciliary body to the is signified or marked by the ora serrata.
This junction marks the transition from the simple, non-photosensitive area of the ciliary body to the multi layered and complex photo synthetic area of the retina.
Answer:
a. fovea centralis
Explanation:
fovea centralis is a thin, central pit composed of closely packed cones in the eye. It is located in the center of the macula lutea of the retina. It is also the center of the eye's sharpest vision and the location of most color perception.
In the root of which of the following are the xylems and phloems arranged in a ring? (A) Gymnosperms.(B) Eudicots.(C) All plants.(D) Monocots.
Answer:
Eudicots
Explanation:
The make up like 75% of flowering plants. Their vascular tissues (xylem and phloem are arranged in a ring like structure
In the root of **eudicots**, the xylem and phloem tissues are arranged in a ring. This type of arrangement is known as the **"vascular cambium"** or **"vascular cylinder."** The corect option is B.
Eudicots, also known as dicotyledonous plants, are one of the two major groups of flowering plants (angiosperms).
1. **Eudicots:** Eudicots are a diverse group of flowering plants that typically have two cotyledons (seed leaves) and exhibit various characteristics, including the arrangement of vascular tissues in their roots. In eudicot roots, the vascular tissues, which include xylem (responsible for water and mineral transport) and phloem (responsible for nutrient transport), are arranged in a distinct ring.
2. **Monocots:** Monocots, the other major group of flowering plants, have only one cotyledon. In monocot roots, the arrangement of vascular tissues is scattered rather than forming a distinct ring. The xylem and phloem are typically arranged in bundles that are scattered throughout the root cross-section.
3. **Gymnosperms:** Gymnosperms, which include conifers and other seed-bearing plants, also have vascular tissues in their roots, but the arrangement can vary. Some gymnosperms have vascular tissues arranged in a more complex manner, rather than a simple ring.
4. **All Plants:** While all plants have vascular tissues (xylem and phloem) responsible for transportation, the arrangement of these tissues in the root can differ based on the plant's evolutionary lineage.
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The hydrolysis of pyrophosphate to orthophosphate is important in driving forward biosynthetic reactions, such as the synthesis of DNA. This hydrolytic reaction is catalyzed in E. coli by a pyrophosphate that has a mass of 120 kd and consists of six identical subunits. For this enzyme, a unit of activity is defined as the amount of enzyme that hydrolyzes 10 umol of pyrophosphate in 15 min at 37 degrees C under standard assay conditions. The purified enzyme has a Vmax of 2800 units per milligram of enzyme.
a) How many moles of the substrate is hydrolyzed per second per milligram of enzyme when the substrate concentration is much greater than Km? (Draw a velocity versus substrate
concentration graph to show your point)
b) How many moles of active sites is there in 1 mg of enzyme? Assume that each subunit has
one active site.
c) What is the turnover number of the enzyme? (Don't bother comparing it to other enzymes;
just show all your own, which equations you use, what numbers you use, where you get them
from, etc.)
Answers:
a) How many moles of the substrate is hydrolyzed per second per milligram of enzyme when the substrate concentration is much greater than Km?
Answer:
31.1 µmol PPi s-1 mg -1
b) How many moles of active site are there in 1 mg of enzyme?
Answer:
5.0 x 10-8 mol
c) What is the turnover number of the enzyme?
Answer:
3732 s-1 per mol enzyme but there are 6 active sites per enzyme therefore turnover is 622 s-1 (per active site)
Explanation:
i have attached two pictures that explains the methodology as i can not write formulas here that's why i solved it and created a picture for attachment.
The turnover number (kcat) of the enzyme can be calculated using the Vmax value and the enzyme concentration, the number of active sites can be determined using the subunit information, and the moles of substrate hydrolyzed per second per milligram of enzyme at Vmax can be calculated.
Explanation:a) When the substrate concentration is much greater than Km, the enzyme is operating at Vmax. The turnover number (kcat) represents the number of substrate molecules converted to product by a single enzyme active site per unit time at Vmax. In this case, Vmax is given as 2800 units per milligram of enzyme. To calculate the moles of substrate hydrolyzed per second per milligram of enzyme, we need to convert the units:
Turnover number (kcat) = Vmax / (enzyme concentration in mg)
Assuming a 1 mg enzyme concentration:
Turnover number (kcat) = 2800 units per milligram of enzyme / 1 mg = 2800 s-1 per milligram of enzyme
b) If each subunit of the enzyme has one active site, then there would be six active sites in the enzyme with a mass of 120 kd. Therefore, the number of moles of active sites in 1 mg of enzyme would be:
Moles of active sites = Number of active sites / Avogadro's number
Number of active sites = 6
Moles of active sites = 6 / 6.022 x 1023 = 9.96 x 10-24 mol
c) The turnover number (kcat) represents the efficiency of an enzyme. It can be calculated using the equation:
Turnover number (kcat) = Vmax / (enzyme concentration in M * moles of active sites)
Using the given Vmax of 2800 units per milligram of enzyme, the enzyme concentration of 1 mg, and the moles of active sites as calculated in part b), we can calculate the turnover number:
Turnover number (kcat) = 2800 units per milligram of enzyme / (1 mg * 9.96 x 10-24 mol) = 2.81 x 1027 s-1 per mol
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Did your pulse change when standing? Why do you think a change did or did not occur?
Explanation:
The pulse of the bodies raises for the first 20 seconds after sitting for a prolonged period of time and then to a standing position. It should, however, return to normal afterwards. The heartbeat of the body decreases because as you travel the blood needs to flow to the active areas and the blood flows downward from gravity, however you still need to pump blood to your brain. The rise in blood demand makes the heart pump more rapidly.
One advantage of storing excess energy as triglycerides as compared to storing it as glycogen is that:a. Triglycerides are stored with water, creating the perfect environment for chemical reactions to release energy. b. One gram of triglycerides contains over twice the amount of energy as one gram of carbohydrate. c. One gram of triglycerides contains over twice the amount of energy as one gram of protein.
Answer: C.
Explanation
There are higher C-H bonds in lipids than in Carbohydrates.
These C-H bonds stored higher chemical potential energy effectively of thr amount (413 kj/mol.)
Carbohydrates has high C-O glycosidic bonds or linkages of ( 358 kj/mol) which stores low amount of energy compare to C-H bonds.
Futher more higher ATPS are produced during ELECTRON TRANSPORT CHAIN REACTION per molecules of tryglycerides metabolize compare to molecules of glucose because the longer chains of lipids ensures that more C-H bonds broken down ,ans therefore more oxidation to supply protons for ATPS synthesis from.proton pumps.
Answer:
b. One gram of triglycerides contains over twice the amount of energy as one gram of carbohydrate
Explanation:
Triglycerides contain more carbon-hydrogen bonds than carbohydrate. One gram of fat, when oxidized, yields approximately twice as much energy as the same mass of carbohydrate.
g Analysis of mitochondrial DNA can answer interesting and important questions. For which of the questions would analyzing mitochondrial DNA be futile? Are you my father? I have poor muscle function, is there something wrong with my ability to make lots of ATP? From biological samplings at a crime scene, can we keep this person as our primary suspect? Are you my long-lost brother? Which is more closely related to the great white shark, the tiger shark or the hammerhead shark?
Answer:
Are you my father?
Explanation:
Mitochondrial DNA is a good tool to identify and to evaluate maternal relatedness.
It can't be used in establishing paternity as barely a small portion of a person's father mitochondria can be inherited.
Suppose there are two genes on two different chromosomes, one gene called G and the other called D. An individual has the genotype GgDd. Which of the following drawings correctly shows cells in this individual after DNA replication but before cell division of the first meiosis? Assume no recombination/crossing-over occurs between the chromosomes.
Answer:
as the question does not contains image i have already mentioned the link to image in ask for detail section therefore i will answer according to that image.
the answer is "B"
Explanation:
Because before crossing over but after duplication both chromosomes will have same alleles as GgDd therefore according to the image the answer will be option "B". as this option showed duplicated chromosomes.
Answer:
The question lacks the image, the image has been added as an attachment.
Based on the attached image, the correct answer is A
Explanation:
DNA replication is the duplication of the genetic material (DNA) found on chromosomes in cells. It results in the production of two identical chromosomes bound together at the centromere. These chromosomes are collectively called SISTER CHROMATIDS and they are identical in the sense that they contain the same alleles of the same gene unlike homologous chromosomes which may contain different alleles of the same gene.
Gene G and D found on the chromosomes undergoes replication to result in exactly the same type of allele in the replicated chromosome as in the template i.e. Allele G will result in allele G on the replicated chromosome or sister chromatid while allele g will result in allele g on the chromatid. The same applies for alleles D and d.
It is important to note that alleles G and g are found on homologous chromosomes i.e similar but non-identical chromosomes received from each parent. They are not identical because they have different alleles.
The dark spot in between the two replicated chromosomes is the CENTROMERE, and it binds the two sister chromatids together.
The question says the two genes are found on different chromosomes. This is evident in option A as we can see the distinct chromosomes carrying the two genes. Option D is a chromosome with the genes on different loci.
Options A and B are wrong because the alleles on each chromatid are different meaning they are not even sister chromatids. This opposes the result of DNA replication. An allele G cannot have an allele g as a replicated pair, same goes for D.
Conservation biologists provide strong arguments about why we should all care about preserving biodiversity. When considering the resources we get from nature as well as the services the ecosystem perform, it is clear that life on Earth is threatened when biodiversity itself is threatened. Which of the following are services by natural, well-functioning ecosystems?
Nutrient cycling
Decomposition of dead orangisms
Dispersal of pollen and seeds
Increase in ambient global temperatures
Purification of air and water
Reduction in the severity of drought and floods
Pollination of crops and natural vegetation
An increase of erosion and siltation along waterways
Source of medicines
Recyling energy to be used again
Regulation of oxygen and carbon dioxide levels
Answer:Increase in ambient global temperatures.
Recyling energy to be used again
Regulation of oxygen and carbon dioxide levels
An increase of erosion and siltation along waterways
Explanation:
Conservational biologists think about the preservation of ecosystem by maintaining the environment in a human control way.
Increase in ambient global temperatures.: The humans must prevent the increase in global temperature worldwide by preventing the rise of greenhouse gases which can lead to global warming worldwide.
Recyling energy to be used again: The sources of energy like wood, waste water can be recycled again for reutilization.
Regulation of oxygen and carbon dioxide levels.: The oxygen and carbon dioxide levels must be regulated. As oxygen is the basic requirement for respiration. The increase in carbon dioxide levels due to human activities is likely to cause respiratory diseases and health hazards in living beings.
An increase of erosion and siltation along waterways.: The erosion and siltation will likely to deposit nutrients and debris which may either contaminate the waterway or may cause eutrophication.
Answer:
Nutrient cycling
Decomposition of dead organisms
Dispersal of pollen and seeds
Purification of air and water
Reduction of the severity of droughts and floods
Pollination of crops and natural vegetation
Sources of medicines
Regulation of oxygen and carbon dioxide levels
Which of the answer choices is a cross section of the highlighted region of the mushroom in the picture
Answer:
The mushroom in the picture and the option choices are included in the attached image. below...
The highlighted region of the mushroom in the picture represents the mushroom's "Gills", and paticularlly the multicellular structure carrying the Hymenium called "the basidiocarp" aka basidioma; the Hymenium or underside of the mushrooms is comprised of vertical plates arranged radially, and if a cross section of this is exposed by making a straight cut through the basidiocarp on a microscope, it would appear as option: (A. )
The cross section of the highlighted region of the mushroom is likely to show the microscopic structure of the gills lined with basidiospores. The images related to the microscopic examination, such as the gill structure and the presence of basidium with basidiospores or clamp connections, help identify this specific section of the mushroom.
Explanation:The student's question appears to involve identifying the cross section of a highlighted region of a mushroom, likely based on microscopy images provided. The mushroom anatomy includes several key components such as the gills, basidiospores, and hyphae with clamp connections. A cross section of a mushroom typically features a detailed view of these structures.
A correct cross section might show the gills of a mushroom, which are thin layers under the cap where spores develop. The basidiospores would be found lining the gills and could be visible as tiny dots or structures on the gills themselves. Hyphae with clamp connections are indicative of the cellular structure of the fungus and can also be present in a microscopic cross-section view.
The provided references, such as descriptions of light microscopy of gill mushrooms and figures showing hyphae from a mushroom, aid in identifying the region as the gills lined with basidiospores. For example, a cross section that captures basidium with basidiospores sitting atop its sterigmata, or one that depicts spores having been released from the sterigmata, would be representative of the cross section of the gills of a mushroom as highlighted in the question.
The bottleneck effect occurs when A. large groups of individuals leave their home population and establish new settlements, mating only among themselves B. many members of a population die, resulting in a great loss of genetic diversity C. many members of a population reproduce causing too much genetic diversity within the population D. small groups of individuals leave their home population and establish new settlements, mating only among themselves.
Answer:
B. many members of a population die, resulting in a great loss of genetic diversity
Explanation:
When certain environmental fluctuations such as reduced food supply or an outbreak of disease result in a sudden decrease in the population size, the population is said to be going through a bottleneck. Bottleneck reduces genetic diversity due to the loss of alleles/genes from the population. Therefore, the death of many members of a population due to some adverse environmental factors and the resultant reduction in genetic diversity represents the bottleneck effect.
Final answer:
Correct option is b. The bottleneck effect describes a scenario in which a population is dramatically reduced in size due to an environmental event, leading to a significant loss of genetic diversity as only a few individuals survive to pass on their genes.
Explanation:
The bottleneck effect occurs when a population undergoes a significant reduction in size, frequently due to a sudden environmental event, such as a natural disaster or disease, which by chance may cause the allele frequencies of the survivors to be different from those of the original population. This results in a loss of genetic diversity and can greatly affect the genetic structure of the resultant population. The correct option that describes this scenario is B. many members of a population die, resulting in a great loss of genetic diversity, as it captures the essence of the bottleneck effect, where only a few members survive to pass on their genes, altering the population's genetic makeup.
Red flowered snapdragons are crossed with white flowered, producing all pink snapdragons in the F1. What would you expect if you crossed red with red?
Select correct answer:
all pink
3/4 red, 1/4 white
all red
1/2 red, 1/2 white
Answer:
well, definitely all red , because in this case there is no white allele for the offsprings from the parents.
Answer:
all red
Explanation:
There is a case of incomplete dominance in the snapdragon since crossing red flower plant with white flower plant results in all pink at F1.
Assuming the allele for flower colour to be R. Red flower will be RR, white will be rr and pink will be Rr.
Hence, if a red flower plant (RR) is crossed with another red flower plant (RR), all the progeny will have RR genotype and will appear red.
The correct option is "all red".
The Vocabulary of Toxicity and Deficiency of Water-Soluble Vitamins
Water-soluble vitamins dissolve in water, and excess intake is generally excreted. Fortification of foods in the United States has reduced the incidence of deficiencies for many of these vitamins, but inadequate intake is still possible. Toxicity is less likely since these vitamins are not stored in the body, but excessive intake can still cause undesirable symptoms in some cases.
Match the words in the left column to the appropriate blanks in the sentences on the right.
a. vitamin B6
b. vitamin B12
c. niacin
d. folate
e. thiamin
f. vitamin C
g. pantothenic acid
1. --------------------------: A deficiency of this vitamin causes beriberi, which is characterized by weakness, swelling, and tingling or numbness in the hands and feet.
2. ------------------------------------ : A severe deficiency of this vitamin causes the disease pellagra.
3.------------------------------ : A deficiency of this vitamin is very rare, but those with inadequate intakes can experience numbness, muscle cramps, and difficulty walking.
4. ----------------------: A deficiency of this vitamin can lead to sore tongue, skin inflammation, depression, confusion, or anemia.
5. -------------------------------: Neural tube defects, like spina bifata, can occur if this nutrient is not consumed in adequate amounts during pregnancy.
6. ------------------- : Those who follow a vegan diet without supplementation are at increased risk of deficiency for this vitamin.
7. --------------------------- : Scurvy symptoms, caused by a deficiency of this nutrient, include rough skin rash and wounds that will not heal.
Here are correct matches for the blanks:
1. --------------------------: A deficiency of this vitamin causes beriberi, which is characterized by weakness, swelling, and tingling or numbness in the hands and feet.
e. thiamin
2. ------------------------------------ : A severe deficiency of this vitamin causes the disease pellagra.
c. niacin
3.------------------------------ : A deficiency of this vitamin is very rare, but those with inadequate intakes can experience numbness, muscle cramps, and difficulty walking.
g. pantothenic acid
4. ----------------------: A deficiency of this vitamin can lead to sore tongue, skin inflammation, depression, confusion, or anemia.
a. vitamin B6
5. -------------------------------: Neural tube defects, like spina bifata, can occur if this nutrient is not consumed in adequate amounts during pregnancy.
d. folate
6. ------------------- : Those who follow a vegan diet without supplementation are at increased risk of deficiency for this vitamin.
b. vitamin B12
7. --------------------------- : Scurvy symptoms, caused by a deficiency of this nutrient, include rough skin rash and wounds that will not heal.
f. vitamin C
Hope it helps!
Water-soluble vitamins are excreted when in excess and hence are generally not stored in the body. Deficiencies can lead to specific diseases like beriberi for thiamin, pellagra for niacin, and scurvy for vitamin C. Ensuring a balanced diet is crucial to prevent these deficiencies.
Explanation:Water-soluble vitamins, including vitamin B6, vitamin B12, vitamin C, niacin, thiamine, folate, and pantothenic acid are essential nutrients absorbed with water and not stored in the body. Matching these vitamins to deficiency symptoms:
thiamin: A deficiency of this vitamin causes beriberi, characterized by weakness, swelling, and tingling or numbness in the hands and feet.niacin: A severe deficiency of this vitamin causes the disease pellagra.pantothenic acid: A deficiency of this vitamin is very rare, but can cause numbness, muscle cramps, and difficulty walking.vitamin B6: A deficiency can lead to a sore tongue, skin inflammation, depression, confusion, or anemia.folate: Inadequate intake during pregnancy can result in neural tube defects like spina bifida.vitamin B12: Vegans without proper supplementation are at risk of deficiency, which may cause various health issues.vitamin C: Scurvy, a deficiency disease of this vitamin, includes symptoms like rough skin rash and non-healing wounds.The presence of multiple hexokinase isozymes (I-IV) for the phosphorylation of glucose enables specific organs to regulate carbohydrate metabolism in a unique way. Hexokinase IV (blue curve in the plot below), also called glucokinase, is the predominant isozyme in liver and has distinct kinetic properties from the other hexokinase isozymes (representative curve in red). Note the difference in the shapes of the curves within the physiological range of glucose concentration (~4 to 6 mM).
Answer:
i could not figure it out though i tried my best
Explanation:
You are studying a disorder that is based on the genetic composition at three loci. Assume that a dominant allele at any locus adds 6 units of risk for the disorder and that a recessive allele at any locus adds 2 units of risk for the disorder. Individuals with 29 or more units of risk develop the disorder. The environment does not affect the presence or absence of this disorder. How many risk units will be present in an individual of genotype AABbCc?
Answer:
28 units
Explanation:
This disorder follows quantitative inheritance. It is controlled by three genes which do not show the usual dominant-recessive relationship . The six alleles individually contribute to the effect which add up to produce the cumulative phenotype. Dominant allele contributes 6 units of risk whereas recessive allele contributes 2 units of risk.
Individual with genotype AABbCc has four dominant alleles (AABC) and two recessive alleles (bc). So their total risk units =
(6*4) + (2*2) = 24 + 4
= 28 units
A famous experiment, Matthew Meselson and Franklin Stahl grew E. coli cells in a medium containing only the "heavy" isotope or nitrogen, ^15N. These cells were then transferred to a medium with the "light" isotope of nitrogen, ^14N. The results of the experiment supported the hypothesis of semi conservative replication, which was proposed by Watson and Crick. Heavy DNA (^15N DNA), hybrid DNA, and light DNA (^14N DNA) can be separated by centrifugation. If cells containing ^15N DNA are transferred to a medium with only ^14N NH_4CI as a nitrogen source, what percent of daughter molecules are composed of hybrid DNA after 3 generations? Predict what percent of daughter molecules would be composed of hybrid DNA if DNA exhibited conservative replication -that is, if a daughter DNA molecule were composed of newly synthesized DNA only.
Answer:
1. 25% percent of daughter molecules are composed of hybrid DNA after 3 generations
2. 0% of daughter molecules would be composed of hybrid DNA if DNA exhibited conservative replication
Explanation:
1. According to semi conservative model of replication, the two DNA strands separate during replication and each gives rise to a new DNA strand. So in a newly synthesised DNA molecule one strand is old and one stand is new.
Here, the medium contained 15N so all DNA molecules had 15N in beginning. Then they were transferred to 14N medium. After first round of replication all the molecules will be 15N14N hybrid since 14N will be used now for replication. After second round of replication 50% of molecules will be 14N14N and other 50% will be hybrid. After third round of replication, 75% molecules will be 14N14N and 25% will be hybrid.
2. According to conservative model of replication, parental DNA strands stay together after replication so a newly synthesised DNA molecule will have both new strands. In this case, a hybrid will never be formed since the 15N15N strand will always remain together and all the subsequent DNA molecules will have 14N14N composition.
Final answer:
After 3 generations in the Meselson-Stahl experiment, 25% of the daughter DNA molecules would be composed of hybrid DNA in semi-conservative replication. In contrast, conservative replication would result in no hybrid DNA molecules, as new DNA would be synthesized entirely from ¹⁴N without incorporating ¹⁵N.
Explanation:
The experiment conducted by Matthew Meselson and Franklin Stahl with E. coli grown in mediums containing heavy (¹⁵N) and light (¹⁴N) isotopes of nitrogen demonstrates the semi-conservative replication model of DNA. After transferring cells from a ¹⁵N medium to a ¹⁴N medium, the distribution of DNA after 3 generations reveals that a specific portion of the daughter molecules will be composed of hybrid DNA (containing both ¹⁵N and ¹⁴N).
After 1 generation, all of the daughter DNA molecules are hybrid, containing one strand of ¹⁵N DNA and one strand of ¹⁴N DNA (100% hybrid DNA).After 2 generations, 50% of the daughter molecules are hybrid DNA and 50% are light DNA (¹⁴N only).After 3 generations, 25% of the daughter molecules are hybrid DNA and 75% are light DNA.In contrast, if DNA replication were conservative, each generation would yield one original heavy (¹⁵N) DNA and one completely new light (¹⁴N) DNA molecule. After 3 generations in a conservative model, there would be no hybrid DNA molecules, as each generation would involve the creation of entirely new ¹⁴N DNA, without integration of ¹⁵N into new DNA strands.
A 68-year old patient with Alzheimer disease was brought to the emergency room by the staff of a local nursing home. He presented as lethargic with a sallow complexion. He had an admission temperature of 102.4F and a respiratory rate of 33/minute. During respiration, the right side of his chest moved better than the left. He showed dense consolidation of the lower lobe of the left lung on physical exam. A sputum sample revealed blood and a greenish color. A chest x-ray showed tight consolidation of the left lung with evidence of formation of cavities in the lung tissue from cytotoxic damage. The patient complained of chills in the exam room, combined with his fever. A smear of his sputum demonstrated no acid-fast bacteria.
Requried:
Diagnose this case study.
Answer:Left Lobar pneumonia
Explanation:
Since the smear test with acid acid fast bacteria is negative,then the test is tuberculosis The respiration, chills,and fever pointed to pneumonia and the consolidation in the left suggested;left lobar.
How are the Earth's crust and humans the most similar according to these graphs? a The largest percentage of both is oxygen. b Silicon is rarely found in nature. c Chemical reactions occur with similar frequency in humans and the Earth's crust. d The smallest percentage of both is potassium.
Answer: Option (a) is the correct option that is largest percentage of oxygen is present in both earth's crust and human body.
Explanation: Oxygen is present in large amounts both in earth's crust and human body. The percentage of oxygen in earth's crust is 46.6% and the percentage of oxygen in the body is about 66.6%. So it is concluded that both human body and earth's crust have high percentage of oxygen.
The relationship of the genome to an organism is similar to that of the __________ to a population.
Answer:
Phenotypes
Explanation:
Genome represents the complete set of genetic material of any organism. It includes all the genes and alleles of that particular organism. The same relationship is between the phenotypes and a population.
The variations in genetic allele pair due to the large set of genome that give rise to varied physical characteristics or traits collectively known as phenotype. The larger is the genome size, the higher will be the variability in phenotypes.
Body color in a fish is controlled by one gene with two alleles. Homozygotes for one allele and heterozygotes are bright red, whereas homozygotes for the other allele are brown. You collect 100 individuals from a population and count 84 red individuals and 16 brown individuals. Assuming that the population is in Hardy-Weinberg equilibrium, what is the frequency of the recessive allele
Final answer:
The frequency of the recessive allele in a fish population where 16 out of 100 individuals display the recessive phenotype is 0.4, calculated using the Hardy-Weinberg principle.
Explanation:
To calculate the frequency of the recessive allele using the Hardy-Weinberg principle, we must first designate the allele frequencies as p for the dominant allele and q for the recessive allele. In the observed fish population with individuals displaying two phenotypes (bright red and brown), we know that brown coloration is the recessive phenotype, which means those individuals are homozygous recessive (qq). Given that there are 16 brown (recessive phenotype) individuals out of 100, we can say that q² (the frequency of the homozygous recessive genotype) is 0.16. To find the frequency of the recessive allele (q), we take the square root of 0.16, giving us q = 0.4. Therefore, the frequency of the recessive allele in the population is 0.4.
Bacteria multiply by division. One bacterium becomes two. Then two divide into four, the four divide into eight, and so on. For a certain strain of bacteria, the time for this division process is one minute. If you put one bacterium in a bottle at 11:00 p.m., by midnight the entire bottle will be full.
1. At what time will the bottle be half full? t realize that 2. Suppose you could be a bacterium in this bottle. At what tim you were running out of space? Explain your response.
Final answer:
In a scenario where bacteria double every minute, the bottle will be half-full at 11:59 p.m., demonstrating exponential growth. The realization of running out of space may only occur moments before the space is fully consumed, highlighting how exponential growth can rapidly lead to reaching limits.
Explanation:
Bacteria multiplying by division is an example of exponential growth, where one bacterium becomes two, and this process repeats in a specified generation time, resulting in the doubling of the population. Given the scenario where a bacterium is placed into a bottle at 11:00 p.m. and the bottle is full by midnight, the key to understanding when the bottle will be half-full lies in realizing the nature of exponential growth. As the population doubles in size each minute, the jar will be half full just one minute before it is full, that is, at 11:59 p.m.
Supposing you were a bacterium in this bottle, the concept of “running out of space” might not become apparent until very late in the growth process. Since the jar is only half full at 11:59 p.m., it may not be obvious to the bacterial population that space is becoming critically limited until moments before it is entirely consumed. This exemplifies how exponential growth can catch populations unaware of looming limits until just before those limits are reached.
After making an observation, a scientist develops a(n) __________ which is a possible explanation for a natural event that is based on existing knowledge and can be tested by experiments.
a.experiment
b.hypothesis
c.results
d.observation
Answer:b.hypothesis
Explanation:the formulation of hypothesis is one of the steps of scientific method.
It is a process scientists used to investigate an occurrence and construct an accurate interpretation.
Observation about a phenomenon is made before an hypothesis is formulated.
The hypothesis is then investigated using experiments.
When it is right ,further experiments are carried out.
But when the hypothesis is wrong,that is the experiments does not confirm it true,the hypothesis will be cancelled or modified