Answer:
Option B
Explanation:
Microbiology is related to the study of microorganisms that are not visible through naked eyes. While virology is the study of viruses. Hence, both option c and d are incorrect. Immunohematology is associated with the study of antigens and antibodies of RBCs in case of blood transfusion.
However, in immunology, the entire immune system is studied inclusive of antigen and antibody interaction, infectious diseases, transplant issues, hypersensitivity etc.
Hence, option B is correct
Yaws is a serious skin disease of children in tropical countries, caused by Treponema pertenue, a species closely related to the bacteria that cause syphilis. Individual cells of T. pertenue are helical, relatively long, and flexible like the one pictured below. These cells are known as _____.
Answer:
The correct answer is- spirochetes
Explanation:
Spirochetes are a group of bacteria which are long, flexible and helical shaped. Some of them are associated with some disease in humans like yawns, lime disease, syphilis, etc.
Yawn is childhood infectious disease caused by a spirochete bacteria called Treponema pallidum pertenue. These bacterial usually affect the children who live in tropical regions like Africa, Southeast Asia. They can affect skin, bones, and joints. They can spread through direct contact with skin sores.
So the cells of T. pertenue which are helical, relatively long, and flexible known as spirochetes.
The human reproductive systemA) is as essential to the survival of an individual as all other anatomic systems.B) remains functional throughout the life of an individual.C) ensures the continued existence of the human species.D) stores but does not produce gametes.E) None of the answers are correct.
Answer:
The correct answer is C) ensures the continued existence of the human species.
Explanation:
The human reproductive system is responsible for the production, storage, and transfer of gametes to the next generation. In the male reproductive system, testes make gametes and in the female reproductive system, ovary makes gametes.
The reproductive system in humans ensures the continued existence of human species in this world because the reproductive system is responsible for gamete fusion and new offspring developments which are more adapted in the environment. This ensures the existence of humans on earth.
In the process of aerobic metabolism, carbon containing molecules are broken down and the energy from the electrons is used to _____________ .
Answer:
Generate of proton gradient that drives ATP synthesis
Explanation:
Aerobic metabolism includes the complete breakdown of glucose or nutrients into CO2 and H2O. During this oxidation, the energy released from the chemical bonds of glucose is stored in reducing powers. These reducing powers are NADH and FADH2. NADH and FADH2 are then oxidized when they give their electrons to the molecular oxygen through an electron transport chain.
During electron transfer, the energy of electrons pumps the protons across the inner mitochondrial membrane and makes the intermembrane space more positive and acidic. This proton concentration gradient later drives downhill diffusion of protons back towards the matrix via proton channels and synthesis of ATP.
If a total of 2000 kcal were consumed (250 grams of carbohydrates, 66 grams of fat, and 102 grams of protein), what percentage of energy comes from carbohydrates, fat, and protein?
A. 30% carbohydrate, 50% fat, and 20% protein
B. 50% carbohydrate, 35% fat, and 15% protein
C. 20% carbohydrate, 30% fat, and 50% protein
D. 50% carbohydrate, 30% fat, and 20% protein
Answer:
D)50% carbohydrate, 30% fat , and 20% protien
Explanation
1 gram of carbohydrate and protien contains almost 9 kcal while 1 gram of lipid contains 9 kcal.
As there is a total of 2000 Kcal. 250 g of carbohydrate will contain 1000 kcal (250 g * 4 =1000kcal). Similarly 66g of fat will contain (66*9=594kcal) .While 102 g of protiens will contain (102 * 4=408kcal). As the percentages are counted by formula Individual calories /total calories * 100. carbs contribute 50% as per the fromula 1000/2000 *100 .Similarly fat contributes 30% as per formula 594/2000 * 100 while protiens contributes 20% as per the same formula 408/2000 * 100.
The correct option is D) 50% carbohydrate, 30% fat , and 20% protein
Calculation of energy percentage:1 gram of carbohydrate and protein comprise nearest of 9 kcal while on the other hand, 1 gram of lipid contains 9 kcal.
For carbohydrate, = [tex]1000\div 2000 \times 100[/tex] = 50%
For fat [tex]= 594\div 2000 \times 100[/tex] = 30%
For proteins = [tex]408\div 2000 \times 100[/tex] = 20%
Based on this above computation, the option D is correct.
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The __________ nerve carries parasympathetic stimulation to the salivary glands, lacrimal gland, and the glands of the nasal cavity and palate.
Answer:
Facial nerve is your answer
A scientist believes that she has found a new life form. Which of the following conditions is not considered essential in determining whether the putative new life form is alive?
a. The creature seems to react to being touched.
b. The creature possesses purposeful anatomical structures that differ from one another.
c. The creature's body is bilaterally symmetrical.
d. It appears to have cells when viewed under a microscope
Answer:
Answer is C, the creature's body is bilaterally symmetrical.
Explanation:
Note that , when an organism is said to be bilaterally symmetrical, it means that , the right side and the left side of the body plan are just like mirror image of each other, when cut or divided along a plane.
In this case, since the scientist just found a new life form, the type of symmetry possess by the organism is never to be considered essential, because if it were to be considered, it will mean the new organism will be terminated or killed to confirm the symmetry, which has automatically negate the process of determining whether the new life form is alive.
Methane-producing archaeons in the rumens of cows and bioluminescent bacteria within the bodies of squid are both examples of _____, where organisms have "evolved together."
Answer:
coevolution
Explanation:
Coevolution is a form of evolution, which involves two or more species interacting together in which each species’ evolution causes a reciprocal effect on the evolution of the other through natural selection. Both species evolved together, thereby forming a kind of symbiotic relationship.
Methane-producing archaeons in the rumens of cows and the bioluminescent bacteria within the bodies of squid are examples of mutualistic relationships in coevolution that are formed as different organism species evolved together.
A scientist suspects that the food in an ecosystem may have been contaminated with radioactive nitrogen over a period of months. Which of the following substances could be examined for radioactivity to test the hypothesis?
a. the cell walls of plants growing in the ecosystem
b. the hair produced by humans living in the ecosystem
c. the sugars produced during photosynthesis by plants growing in the ecosystem
d. the cholesterol in the cell membranes of organisms living in the ecosystem
Answer: A and B
Explanation: The hair stores an amazing amount of nitrogen, so it makes sense that an increase above the normal concentrations contained in it would serve to detect abnormal levels of nitrogen in the environment, especially if it was radioactive, as it would also contain radioactive nitrogen. Contaminants have been
reported to affect cellular organelles and components such as cell membrane, which destabilizes the lipid bilayer conformation. Cells counteract this effect by reducing the nonbilayer phospholipid fraction to increase membrane stability this phenomenon can also be used in detecting contamination.
The following substances could be examined for radioactivity to test the hypothesis - B. the hair produced by humans living in the ecosystem.
The hair contains keratin which is a protein. Proteins are made up of amino acids that contain nitrogen in their structure that can be easily replaced by radioactive N.
the radioactive nitrogen will get incorporated into the newly forming proteins in the hair of humans. So, they can be tested for radioactivity. The cell wall is made up of cellulose which is a polymer of glucose and has no nitrogen in its structure Cholesterol is a type of lipid with a sterol nucleus. It has no nitrogen in its chemical structure The sugars produced during photosynthesis do not have any nitrogen in their structure. The structure of glucose can confirm this, therefore, they will not incorporate the radioactive nitrogen in themThus, The following substances could be examined for radioactivity to test the hypothesis - B. the hair produced by humans living in the ecosystem.
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A global alignment algorithm (such as the Needleman-Wunsch algorithm) is guaranteed to find an optimal alignment. Such an algorithm:________.
A) Puts the two proteins being compared into a matrix and finds the optimal score by exhaustively searching every possible combination of alignments.
B) Puts the two proteins being compared into a matrix and finds the optimal score by iterative recursions.
C) Puts the two proteins being compared into a matrix and finds the optimal alignment by finding optimal sub-paths that define the best alignment(s).
D) Can be used for proteins but not for DNA sequences %.
Answer:
Option (C).
Explanation:
The alignment of the particular sequence can be used to determine the property, structure or the evolutionary relationship of the particular gene. The BLAST ca be used for the alignment.
Needleman-Wunsch algorithm is used to understand the alignment of the molecules especially protein and nucleotides. In this case, the two different proteins or molecules are compared by using the optimal alignment and the sequence is then determined.
Thus, the correct answer is option (C).
The Needleman–Wunsch algorithm is an algorithm used in bioinformatics to align protein or nucleotide sequences. It was one of the first applications of dynamic programming to compare biological sequences.
The alignment of the particular sequence can be used to determine the property, structure, or evolutionary relationship of the particular gene.
The BLAST can be used for the alignment.
Needleman-Wunsch algorithm is used to understand the alignment of the molecules especially protein and nucleotides.
In this case, the two different proteins or molecules are compared by using the optimal alignment, and the sequence is then determined.
Thus, the correct answer is an option (C).
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By definition, "living things, or organisms, all share certain characteristics that, taken together, define life." Which of the statements below would not be correct with respect to this statement?
Answer: Organisms grow and reproduce sexually
Explanation: brainly pls
Answer:Organisms grow and reproduce sexually
Explanation:
Herbicides are being used to kill weeds in a nearby field. The plants absorb the herbicides from the soil. Which organelle in the plant will most likely store the absorbed herbicide waste?a. ribosome.b. vacuole.c. chloroplast.d. mitochondrion.
Answer: The correct answer is Vacuole
Explanation:
The vacuole is an organelle found in the central portion of plant cells, and is usually filled with cell sap that acts as a "store house" for many substances entering into the cell.
Therefore, the herbicide waste absorbed by the plants will be stored in the VACUOLE.
Vacuole in the plant will most likely store the absorbed herbicide waste.
Vacuole is an important site for the degradation of cellular lipids, membrane-associated proteins, and cytoplasmic proteins
What is Vacuole?Vacuoles are organelles of plant, fungal, and algal cells. They are part of the internal membrane system and are separated from the rest of the cytoplasm by a membrane called the tonoplast .
The term “vacuole” means “empty space”. They help in the storage and disposal of various substances. They can store food or other nutrients required by a cell to survive. They also store waste products and prevent the entire cell from contamination.
The vacuoles in plant cells are larger than those in the animal cells and occupies more than 80% of the volume of the cell. It may be single or more in number.
Structure:
A vacuole is a membrane bound structure found in the cytoplasmic matrix of a cell.
The components of the vacuole, known as the cell sap, differ from that of the surrounding cytoplasm.
The membranes are composed of phospholipids and are embedded with proteins helping in transporting molecules across the membrane. Different combinations of these proteins help the vacuoles to hold different materials.
Vacuoles perform three specific types of functions:
- Storage:
It stores salts, minerals, pigments and proteins within the cells. The vacuole is also filled with protons from the cytosol helping in maintaining an acidic environment within the cell and a large number of lipids are also stored within the vacuoles.
- Turgor Pressure:
Vacuoles are filled with water exerting pressure on the cell wall called as Turgor Pressure providing shape and helping to withstand extreme conditions.
- Endocytosis and Exocytosis:
Substance entering through the vacuole is called as endocytosis and excreted through Exocytosis.
Vacuoles play crucial roles in
- cell expansion
- function as lytic organelles that contain digestive enzymes
Compounds contained within vacuoles also protect cells against environmental damage and deter attack by herbivores .
What are the other Cell Organelles?Ribosomes:
A ribosome is a complex molecular machine found inside the living cells that produce proteins from amino acids during a process called protein synthesis or translation.
Ribosomes also functions by binding to a messenger ribonucleic acid (mRNA) and decoding the information carried by the nucleotide sequence of the mRNA.
Chloroplast:
It is a cell organelle comes under the category of Plastids which are exclusively present in Plant cells.
These plastids are double-membraned cell organelles which play a primary role in the manufacturing and storing of food.
Types of plastids –
Chromoplasts- They are the color plastids, found in all flowers, fruits and are mainly responsible for their distinctive colors.
Chloroplasts- They are green coloured plastids, which comprise green-coloured pigments within the plant cell and are called chlorophyll.
Leucoplasts- They are colorless plastids and are mainly used for the storage of starch, lipids and proteins within the plant cell.
Mitochondrion:
Mitochondria are membrane-bound cell organelles that generate most of the chemical energy needed to power the cell's biochemical reactions. Chemical energy produced by the mitochondria is stored in a small molecule called adenosine triphosphate (ATP).
Thus it is also called as power house of the cell.
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If protease treatment in Avery, MacLeod, and McCarty's experiment prevented the transformation of bacteria, what would have been the conclusion of these researchers?
Answer:
Protein is the genetic material; not DNA.
Explanation:
In Avery, MacLeod, and McCarty's experiment, digestion of proteins with the enzyme protease and use of this extract from the heat-killed S cell did not affect its ability to transform the R cell into the S cells. However, there was no transformation when the cellular extract of heat-killed S cells was treated with DNAse enzyme. They concluded that DNA was the genetic material responsible for transformation.
If protease treatment of cellular extracts of heat-killed S cell would have prevented the process of transformation, protein would have been concluded to be the genetic material.
The circulatory systems of land-dwelling vertebrates are composed of two pumping circuits: the systemic circulation, which is a lower-pressure circuit to the lung, and the pulmonary circulation, which is a higher-pressure circuit to the rest of the body.
A. True
B. False
Answer:
Answer is False.
Explanation:
The answer is false because the pulmonary circulation is the lower pressure circuit to the lung while the systemic circulation is higher -pressure circuit to the lung.
The two, that is , the systemic circulation and pulmonary circulation are ways of circulatory system.
The circulatory system transport liquid, exchanges gases, nutrients, and wastes with the cells in the body.
What would happen if a seed from a self-fertile olive tree landed on an island under ideal growth conditions with no herbivores or pathogens, such that all individuals survived?
Answer:
The population of olive would grow
Explanation:
As olive seed germinate, grows into a seed producing olive tree, when the seeds start falling around or propagated by wind to land on favorable soil around the island, they start to germinate and grow all around the island.
Mendel crossed plants that produced only round seeds to those that produced only wrinkled seeds. In the next generation, all the pea plants produced only round seeds. Which term describes how the round-seed allele is inherited?
Answer:
Dominance
Explanation:
Mendel discovered certain principles that governs heredity or inheritance when he conducted experiments. In his experiments, he discovered that an organism receives two copies of a gene called allele, from each parent.
He discovered that one allele of a gene has the ability to mask or suppress the expression of its allele variant in the same gene. He called the allele that masks or is expressed, DOMINANT allele, while the allele that is masked, RECESSIVE allele. Based on this observation, he named his first principle, LAW OF DOMINANCE.
In this case, he crossed a purebreeding round-seeded pea plant and a purebreeding wrinkled-seeded pea plant, he noticed that in the F1 generation, all the offsprings possessed round seeds. This led to the conclusion that the allele for round seeds masks the phenotypic expression of the wrinkled allele in a heterozygous state. Hence, the allele for round seeds is dominant while the allele for Wrinkled seeds is recessive.
What is the nutritive fluid flowing through the circulatory system? A. Lymph B. Blood C. Pus D. Water
Answer: The answer is blood
Explanation:
The blood is the 'fuel' of the circulatory system in that it carries nutrients ranging from
- gases like oxygen by the help of its respiratory pigment, hemoglobin
- rich food substances like glucose, amino acids to various cells of the body
- antibodies and hormones that provide defence against invaders
Thus, the blood is the nutritive fluid of the circulatory system
The nutritive fluid flowing through the circulatory system is Blood, transporting nutrients and waste materials. Lymph, another body fluid, functions primarily in the lymphatic system.
The nutritive fluid that flows through the circulatory system is B. Blood. Blood, a type of fluid connective tissue, circulates within the body, transporting nutrients, salts, and waste materials. It consists of cells, like red and white blood cells, suspended in a liquid matrix called plasma.
Lymph is another important fluid in the body that functions mainly in the lymphatic system. It is a watery fluid that bathes tissues and organs and contains protective white blood cells. It does not circulate throughout the body in the same way as blood and is not pressurized by the heart. Lymph moves in one direction from extremities towards two drainage points into veins just above the heart.
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_________ is the jellylike solution within a cell that contains everything between the nucleus and the plasma membrane.
Answer: Cytoplasm
Explanation:
The cytoplasm is a fluid material in which several organelles located between the nucleus and plasma membrane are suspended, they organelles include:
- lysosomes
- golgi bodies
- endoplasmic reticulum
- mitochondria
- vacuoles etc.
______________ these compounds regulate cell division rates, maintain normal kidney function and fluid balance, direct hormones to their target cells, regulate the flow of substances in and out of cells, and regulate ovulation
Full question:
___________ these compounds regulate cell division rates, maintain normal kidney functions, and fluid balance, direct hormones to their target cells, regulate the flow of substances in an out of cells and regulate ovulation.
a- triglycerides
b- amino acids
c- eicosanoids
d- carbohydrates
Answer:
Eicosanoids these compounds regulate cell division rates, maintain normal kidney functions, and fluid balance, direct hormones to their target cells, regulate the flow of substances in an out of cells and regulate ovulation.
Explanation:
Eicosanoids behave like hormones, but they did not desire to move. Eicosanoids sometimes seem on cells nearby to their locality of composition. Eicosanoids also swiftly split down, so they are incapable of progress quite notably. Most eicosanoids are created from arachidonic acid.
Hen, eggs, burgers are samples of meals that render arachidonic acid. The eicosanoids obtained from certain fatty acids possess a diversity of consequences on your body. They also modify the insusceptible rejoinder and several respiratory and generative processes.
You are reading a blog written by a student who is working at an archeological dig in Cyprus. She mentions that they just uncovered an ancient burial site in which the skeletal remains of a human are found next to those of a cat. The arrangement of the bones suggests that the cat was buried with its owner and may have been a pet. Remarkably, the location of the grave relative to other known artifacts suggests it is 10,000 years old. If this is correct, then this is the earliest evidence for cat domestication. The blog author suggests that dendrochronological analysis of some of the wood fragments found nearby, together with C14 analysis should confirm the dates. You are not so sure these two methods will work equally well. Which method is most likely to shed accurate insight into the age of these two skeletons? Why?
Answer:
Obviously C-14 Method...
Explanation:
First things to clear first that the dendrochronological analysis is used only for plants that are alive. the second thing to under stand is that this analysis of a wood fragment would only give ages according to the size and number of rings present in the bark of wood.
The C-14 is a highly effective way because it can give aging analysis even for a million years or so and scientists used it everyday to predict the age by analyzing decayed organic carbon isotope C-14 present in every life form dead or alive on Earth.
Which types of claims on food labels are strictly regulated by the Food and Drug Administration (FDA)? A. Nutrient claims and structure/function claims. B. Nutrient claims and health claims. C. Nutrient claims, health claims, and structure/function claims. D. Structure/function claims and health claims.
Answer:
Option-C
Explanation:
FDA or U.S Food and Drug Administration is a government agency which aims at protecting the public health by ensuring the efficacy, safety and security of food products, drugs and other medical devices, cosmetics.
The FDA regulations suggest that a food product must have three types of claims on it which are:
1. The health claim in which the relation between the food ingredient and health-related issues are mentioned.
2. The Nutrient claim which mentions the level of a nutrient in a food.
3. Structure/Function Claims which describe the role of nutrients on the human body.
Thus, Option-C is the correct answer.
The FDA is the government agency and the main role of these agency to protecting the health of the people by ensuring and check there will be no adulteration in the food .
As per the information given , the suitable answer will be claim of health , nutrient and structure claims.
Nutrient play very important part in our health as if our intake of nutrient is correct and healthy then our body will function correctly and it is the main duty of FDA to check and take all the precaution fo maintain the high standard of foods.
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In Guided Lab A you found the shortest distance from the center of the Mt. Vesuvius crater to the coast, in kilometers and miles. What is the distance in kilometers?
Answer:
7 km
Explanation:
In Guided Lab A you found the shortest distance from the center of the Mt. Vesuvius crater to the coast, in kilometers and miles, the distance in kilometers will be 7 while the distance in miles will be 4.
Hox genes are thought to play an important role in the development of different morphologies because _____.
Answer: They provide positional information in the
The regulation of blood flow by local mechanisms within a capillary bed is called
Complete question:
The regulation of blood flow by local mechanisms within a capillary bed is called
A) autoregulation.
B) hormonal regulation.
C) hemoregulation.
D) vasoregulation.
E) neuroregulation.
Answer:
A) autoregulation.
Explanation:
Local changes regulate the flow of blood in each capillary bed. This occurs when the vasodilators trigger the local widening of arterioles and relaxation of precapillary sphincters to increase the blood flow into capillary networks. On the other hand, vasoconstrictors reduce blood flow. This ability of a tissue to control blood flow to meet its metabolic demands is called autoregulation.
For example, autoregulation increases the blood flow in the heart and skeletal muscle during physical activities to meet the increased demand for O2 and nutrients.
Autoregulation is the local regulation of blood flow in a capillary bed. This process lets tissues adjust their blood flow based on the body's needs, and involves mechanisms like the opening and closing of precapillary sphincters. Other systems like neural and endocrine mechanisms also help ensure adequate blood flow and perfusion.
Explanation:The regulation of blood flow by local mechanisms within a capillary bed is called autoregulation. This local, self-regulatory mechanism allows each region of tissue to adjust its blood flow, and thus its perfusion, based on the body's needs. These mechanisms are neither stimulated by the nervous system nor controlled by endocrine signals.
For instance, during strenuous exercise when oxygen levels decrease and carbon dioxide, hydrogen ion, and lactic acid levels increase, the capillary beds in skeletal muscle open, allowing more blood flow. This process is controlled by small muscles called precapillary sphincters. If these sphincters are open, the blood will flow into the associated branches of the capillary blood.
There are other homeostatic mechanisms in place to ensure adequate blood flow, blood pressure, and ultimately perfusion. These include neural, endocrine, and autoregulatory mechanisms.
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Frequently, important DNA regions with specific functions tend to contain short stretches of nucleotides that are conserved across different organisms (e.g., promoter sequence) and are recognized by specific proteins. What are these conserved sequences called?A. InitiatorsB. Critical elementsC. CodonsD. Repetitive sequencesE. Consensus sequences
Answer:
The correct answer is E. Consensus sequences
Explanation:
A consensus sequence are considered in nucleic acid and protein which is recognized by specific protein like RNA polymerase. In nucleic acid, these sequences are short nucleotide stretch which are conserved across different organism and reflects most common bases at each position in a segment alignment.
Example of a consensus sequence is promoter sequence. In bacteria, the promoter region contains two regions of consensus sequence characterized by -10 and -35 sequence. RNA polymerase recognizes this consensus sequence and binds to the promoter region. Therefore the correct answer is E.
Arrange the events in the stimulation of heart muscle in order from earliest (1) to latest (5). Note that this question does not list every step in the pathway, but the steps presented should be arranged in order.
Answer:
1) Pacemaker impulse generation.
2)AV node impulse conduction
3) AV bundle impulse conduction.
4) Bundle branches conduction.
5) Purkinjie fibres impulse conduction.
Explanation:
The cardiac conduction has following components.
1)SA node is the heart pacemaker in the right upper quadrant of heart. It generates electrical impulses and these impulses then move through atria and AV node to the Purkinjie fibres.
2) The impulses reach AV node. It controls heart rate. It serves as electrical relay station which slows the electrical current sent by SA node before the signals has passed to ventricles.
3) AV bundle is continuation is AV node and it transmits impulse from AV node to the Purkinjie fibres.
4) Electricle impulses from bundle of his passes through bundle branches (right and left ) to Purkinjie fibres.
5)Purkinjie fibres take the impulses from the bundle branches to the myocardium of ventricles.
Contrast the genetic content and the origin of sister versus nonsister chromatids during their earliest appearance in prophase I of meiosis.
Complete question:
Question: Contrast the genetic content and the origin of sister versus nonsister chromatids during their earliest appearance in prophase I of meiosis.
a) Sister chromatids are genetically similar, except where mutations may have occurred during DNA replication. Nonsister chromatids are genetically dissimilar.
b. Sister chromatids are genetically identical, except where mutations may have occurred during DNA replication. Nonsister chromatids are genetically similar if on homologous chromosomes and genetically dissimilar if on nonhomologous chromosomes.
c. Sister chromatids are genetically identical, except where mutations may have occurred during DNA replication. Nonsister chromatids are genetically similar.
d. Sister chromatids are not genetically similar, except where mutations may have occured during DNA replication. Nonsister chromatids are genetically similar if on homologous chromosomes and genetically dissimilar if on nonhomologous chromosomes.
Answer:
b. Sister chromatids are genetically identical, except where mutations may have occurred during DNA replication. Nonsister chromatids are genetically similar if on homologous chromosomes and genetically dissimilar if on nonhomologous chromosomes.
Explanation:
A chromosome has two chromatids after the S phase of the cell cycle. The replicated DNA molecules are accommodated in the sister chromatids. Therefore, two chromatids of a chromosome carry the identical DNA molecule and are genetically identical to each other. The sister chromatids may carry different genes if one or more mutation occurs in their DNA.
Two chromatids of two different chromosomes are called non-sister chromatids. Homologous chromosomes are the chromosomes that are similar in morphology and genetic constitution. Therefore, two chromatids of a homologous pair are also non-sister chromatids but have genetically identical sequences. For example, the two non-sister chromatids of the pair of chromosome 21 in humans carry the alleles for the same genes.
However, the non-sister chromatids that belong to nonhomologous chromosomes carry different genes and are not genetically identical.
Before replication can take place.(1) A. DNA polymerases must add complementary nucleotides to DNA. B. the two strands of DNA must separate. C. the covalent bonds in DNA must break. D. helicases must break the bonds in the nucleotides.
Answer:
The correct answer is B. the two strands of DNA must separate.
Explanation:
DNA is a double-stranded structure. The two strands are joined together by the formation of hydrogen bonds between complementary nucleotides. So before the replication takes place these two strands must be separated.
The separation of DNA strand is accomplished by the action of a helicase enzyme which breaks the hydrogen bond between complementary nucleotides and separated the two DNA strands.
After separation, the DNA polymerase binds to separated DNA and replicating the DNA. So the right answer is B.
Final answer:
The correct option is B. The two strands of DNA must separate. The first step before DNA replication can occur is the separation of the two strands of DNA, which is facilitated by the enzyme DNA helicase.
Explanation:
Before replication can take place, the correct answer to the student's question is B. The two strands of DNA must separate. This separation is carried out by an enzyme known as DNA helicase, which unwinds and opens up the double helix at the origin of replication. Once the strands are separated, single-strand binding proteins prevent the separated strands from re-annealing, thus allowing each strand to serve as a template for replication. Following this, RNA primers are added by the enzyme primase, which provides a starting point for DNA polymerase to begin adding nucleotides to form a new strand of DNA.
A trait that confers a greater level of fitness, relative to those who lack it, is called a(n) ________.
Answer: Adaptation
Explanation:
The adaptation is the process by which a species becomes fitted to its environment which is a direct result of natural selection.
The traits that best suits the organism in an extreme conditions and helps in better survival is known as adaptation.
The variation in the species can be favored or rejected based on the condition. If the variation helps in survival of the organism in a better way then it is favored and if it is does not favors its survival then it is not carried further.
The best suited character is adapted and carried forward.
You have found a new organism and need to classify it. It has no nucleus and was found living several feet below in an ice sample. This organism would most likely be classified as:_________.
Answer:
Bacteria
Explanation:
Unicellular organisms that lack nucleus or chlorophyll hence are neither plants or animals are classified as Bacteria.
They are known to survive extreme environment such as saline , extremely hot or cold environment.
The new organism had been found several feet below in an ice sampe. This is an extremely cold only a Psychrophillic organism can survive here. The organism is most likely to be classified as a Bacteria .
The formation of ATP in a muscle cell is an _______________ reaction, whereas using ATP for contraction is an _____________ reaction
Answer:
1. endergonic
2. exergonic
Explanation:
The formation of ATP is an endergonic reaction. It means that the reaction requires the input of energy to be performed. Muscle cells form ATP mainly during the oxidative phosphorylation of cellular respiration. The proton concentration gradient across the inner mitochondrial membrane drives the endergonic phosphorylation of ADP into ATP. ATP hydrolysis releases energy and is an exergonic reaction. Removal of the phosphate group reduces the electrostatic repulsion between the negative charges present on the three phosphate groups of ATP.
The formation of ATP in a muscle cell is an endothermic reaction and using it for muscle contraction is exothermic. Creatine phosphate helps replenish ATP during muscle contractions, and different pathways are used depending on the presence of oxygen.
The formation of ATP in a muscle cell is an endothermic reaction, whereas using ATP for contraction is an exothermic reaction. The creatine phosphate system operates to regenerate ATP. When oxygen levels are high, ATP combines with creatine to form ADP and creatine phosphate, storing energy. As ATP levels fall during muscle contractions, this reaction reverses to quickly resupply ATP. In the presence of oxygen, cells also produce ATP through aerobic respiration, whereas in its absence, ATP is derived from anaerobic respiration. Moreover, different muscle fibers like slow oxidative (SO), fast oxidative (FO), and fast glycolytic (FG) have varying abilities to regenerate ATP, which consequently affects their contraction dynamics and fatigue rates. Aerobic metabolism is the primary method for sustained muscle contraction, as it can produce more ATP than the other two mechanisms.