Answer:
The correct answer will be option-D.
Explanation:
Before Citric acid cycle or Krebs cycle, an intermediate reaction takes place which converts the pyruvate into Acetyl CoA. This reaction is known as pyruvate decarboxylation as it produces Carbon dioxide.
Coenzyme A reacts with pyruvate which causes the release of two oxygen atoms and one carbon to form CO₂ along with the reduction of NAD+ to NADH and produce "Acetyl CoA."
Thus, option-D is the correct answer.
The intermediary metabolite formed by the removal of CO2 from pyruvate and that enters the Krebs cycle is acetyl CoA. This occurs in the phase of cellular respiration known as decarboxylation.
Explanation:The intermediary metabolite that enters the Krebs cycle and is formed, in part, by the removal of a CO2 molecule from a molecule of pyruvate is acetyl CoA (option D).
The process occurs during cellular respiration. Specifically, one carbon atom from pyruvate is released as one molecule of CO2 in a step called decarboxylation, facilitated by an enzyme complex in the mitochondrial matrix. This remaining two-carbon molecule then combines with Coenzyme A to form Acetyl CoA, which enters the Krebs cycle.
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Describe the key steps in the semiconservative replication of DNA.
Answer:
Semi-conservative replication is meant for the description of DNA replication and it i s called so because parent DNA helix produces two copies of original DNA, one of which consist of original DNA.
The three main steps in DNA replication includes Initiation, Elongation and Termination.
In the initiation phase, replication begins at origin of replication where helicase enzyme breaks the hydrogen bonds between base pairs and tends to unwind the double helix where the topoisomerase stabilizes the newly formed single strand DNA. DNA polymerase allows elongation to occur in leading direction and catalyses the addition of new nucleotide to new single strands. short sequences of RNA called primers paired to template strands with the help of primase. replication of both strands occurs at the same time one in continuous (3'-5') and other in discontinuous (5'-3') direction, which are called leading strands. new nucleotides added in 3' end and moving to replication fork while discontinuous synthesis occur on parent strand (5'-3') called lagging strand and completed in segments called okazaki fragments. Then primase add primers ahead at 5' end of the lagging strand. DNA polymerase ||| adds short sequences of nucleotides to the primer. During termination, exonuclease replaces DNA primer and DNA nucleotide and DNA ligase helps in making bonding between fragments and replaced nucleotide. Another exonuclease helps in proofreading the newly formed DNA and corrects the errors in sequences. At the end of the parent strands, telomeres are present which keeps on catalyzing by telomerase and completes, the formation of copies of parent DNA.
The semiconservative replication of DNA is a process where each new DNA molecule consists of one parental and one new strand. This process includes unwinding the DNA, helicase creating replication forks, binding proteins stabilizing single strands, and enzymatic actions such as Primase synthesizing RNA primers, DNA polymerase elongating new strands, and DNA ligase sealing the strands.
Explanation:Semiconservative Replication of DNAThe key steps in the semiconservative replication of DNA involve several critical actions and proteins to ensure that the DNA is copied accurately. The term semiconservative relates to the fact that each resultant DNA molecule consists of one old (parental) strand and one new (daughter) strand. The replication process can be described as follows:
DNA unwinds at the origin of replication.Helicase opens up the DNA, forming replication forks; these extend bidirectionally.Single-strand binding proteins coat the DNA strands to prevent them from rewinding.A short RNA primer is synthesized by Primase, which is necessary for DNA polymerase to begin synthesis of the new strand.DNA polymerase III attaches nucleotides to the 3'-OH group of the RNA primer, elongating the new strand.As synthesis proceeds, DNA polymerase continually adds new nucleotides to the growing strand in accordance with the base-pairing rules (A pairs with T, C pairs with G).Once the entire DNA molecule has been copied, DNA polymerase I replaces the RNA primers with DNA nucleotides.The DNA ligase enzyme seals the gaps between the newly synthesized DNA fragments, finalizing the strand.The result is two DNA molecules, each with one parental strand and one new strand - this conservation of the parental strand is why the process is known as semiconservative.What do climate change (see Concept 1.1 and Concept 3.2) and ocean acidification have in common?
The cause of climate change and ocean acidification are the same, i.e., burning the fossil fuels.
When animals and plants decompose, in the earth crust, over the years, it leads to formation of fossil fuels.
Burning of fossil fuels can cause an increase in the level of carbon dioxide in the atmosphere, this results in the ocean acidification and climate change activities.
Long-term changes in temperatures and weather patterns, mostly brought on by human activity, most notably the combustion of fossil fuels, are referred to as climate change.
The term “ocean acidification” describes a long-term decrease in the pH of the ocean that is principally brought on by the absorption of carbon dioxide (CO2) from the atmosphere.
To culminate, burning of fossil fuels lead to changes in the temperature and pH of the environment, which result in the climate change and ocean acidification.
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Climate change and ocean acidification are primarily caused by increasing atmospheric carbon dioxide levels due to human activities. These processes have damaging effects on ecosystems, especially marine life, and are closely interrelated with each other.
Explanation:Climate change and ocean acidification share a common cause and consequence. They both are caused primarily by the increasing level of atmospheric carbon dioxide due largely to human activities. As the concentration of carbon dioxide increases in the atmosphere, it also increases in the oceans, causing the seawater to become more acidic, a process known as ocean acidification. This can have detrimental effects on marine organisms, particularly coral reefs which are highly sensitive to changes in pH. Similarly, the rise in carbon dioxide in the atmosphere contributes to global climate change, altering global weather patterns, and resulting in a worldwide increase in temperature.
Furthermore, both these phenomena have interconnected impacts. For instance, global warming due to climate change also causes ocean warming, making oxygen less soluble in seawater and exacerbating the impacts of ocean acidification. In conclusion, both climate change and ocean acidification are interrelated problems, primarily driven by rising atmospheric carbon dioxide levels, and have substantial implications on our ecosystems.
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Proteins are broken down into ___________ by the enzyme ____________
Answer: Proteins are broken down into amino acids by protease enzymes.
Explanation:
Protein is an essential nutrients which is needed for growth and development. Protein is the major constituent of hormones, enzymes, eyes, muscles e.t.c.
The protein sources are eggs,beans,meats, milk e.t.c.
Protein digestion start in the stomach. Once protein consume get to the intestine, hydrochloric acid and protease enzymes breakdown protein into amino acids.The Amino acids are linked together by peptides bond. The perform this by cleaving to the peptides bond within the protein by a process called hydrolysis.
Categorize allele interactions as completely dominant, incompletely dominant, or codominant.
Answer:
Explanation:
Gregor Mendel showed his inheritance character in the garden pea plant. According to him, there are 2 alleles which are inheritable - dominant allele and recessive allele. The dominant allele is always dominant over the recessive one which is known as the complete dominance. When the offsprings have both recessive alleles it will show its character.
There are other characters present besides dominant and recessive. Such characters are known as Mendelian deviation as it does not obey Mendel's law of inheritance. e.g. codominance, incomplete dominance.
In codominance alleles, characters are blended and a new character has seen in the next generation. This new character is neither dominant not recessive, it is an intermediate character between the 2 characters.
e.g When the white and red flowers crossed pink flowers are formed along with red and white.
In the case of codominance, both alleles express their characters. Such phenotypic characters are known as codominance because both alleles are expressed in the offsprings.
e.g. When the red and white flower plants crossed the offspring flowers are red with white spots or the white with red spots.
Which gland of the cane toad produces poison?
a. parotoid gland
b. tympanic membrane
c. glottis
d. eustachian tubes
Answer:
The correct option is: a. parotoid gland
Explanation:
Cane toads, also known as Bufo marinus or Rana marina Linnaeus, are the giant old species of the terrestrial true toads. The female cane toads are longer than the male cane toads.
The skin of the cane toad is highly toxic. An adult cane toad has large parotoid gland behind each eye, which secretes a milky-white toxic fluid called bufotoxin.
Describe the key chromosome behaviors during mitosis.
Answer:
Explanation:
During mitosis, the chromosomes are distributed equally in the resulting chromosome. The chromosome number was doubled in the S phase of the interphase and the cell is ready for mitosis. The chromosomes are more condensed and twisted in prophase. It is also double in length. During the metaphase, the chromosomes are arranged in the metaphase plate. The microtubules from the centriole attach to the centromere of each chromosome and pull them towards the pole.
Thus each chromatid pulls apart and migrates towards the poles. The nuclear membrane and nucleus disappear during mitosis. At the end of telophase, the daughter cells contain an equal number of chromatids as in the parent cell.
Sometimes the microtubules of centrioles do not function properly and fail to pull the chromosomes equally to the cells. Thus one of the daughter cells contains more chromosomes and another fewer chromosomes. This occurs in anaphase. This results in the non-disjunction of chromosomes.
Sometimes centromere splits transversely instead of longitudinal division. This results in the formation of 2 daughter chromosomes of unequal length. This is called the isochromosomes.
The number of chromosomes distributed in the daughter cells results in a normal cell or any genetic disorder. The main function of mitosis to produce daughter cells having an equal number of chromosomes present in the parent cell.
The androgen-binding protein functions to
A. Confer responsiveness of certain cells to male sex hormones.
B. Transport androgens in the plasma.
C. Bind and maintain high concentrations of testosterone in the seminiferous tubules.
D. A and B.
E. A, B and C
Answer:
C. Bind and maintain high concentrations of testosterone in the seminiferous tubules.
Explanation:
Seminiferous tubules are present within the testis of male reproductive system. In adults, each testis is oval in shape and is about 4-5 cm in length. Each testis has about 250 compartments called testicular lobules. These compartments contain highly coiled tubules called seminiferous tubules.
Within the seminiferous tubules, the male gamete i.e sperms are produced. Seminiferous tubules are lined inside by two types of cells called male germ cells (spermatogonia) and sertoli cells.
Spermatogonia give rise to spermatozoa which are released into the lumen of the tubule. In between spermatogenic cells, sertoli cells or sustentacular cells or nurse cells are present which provide nourishment to developing spermatozoa.
One of the function of sertoli cells are to release androgen binding protein (ABP) which binds and concentrates testosterone with in the seminiferous tubules.
The hormone testosterone is produced by the interstitial cells of Leydig located around the seminiferous tubules.
In a hemoglobin variant known as hemoglobin Kansas, an Asparaginein
the beta chain is replaced by a Threonine. This results in
thedisruption of a hydrogen bond that normally stabilizes the
R-stateof hemoglobin. Which statement is FALSE regarding the effect
thisamino acid change has on the ability of hemoglobin Kansas to
bindoxygen?
a. Inhemoglobin Kansas, there is an increase in the amount of
R-stateand a decrease in the amount of T-state.
b. In hemoglobinKansas, there is a decrease in the amount of
R-state and anincrease in the amount of T-state.
c. The R-state inhemoglobin Kansas is less stable than
normal.
d. The presence ofless oxy-Hb in hemoglobin Kansas indicates this
type of Hb has alower affinity for oxygen.
e. The p50 forhemoglobin Kansas is higher than normal.
Answer:
The false statement is option a.
Explanation:
If there occurs a disruption of a hydrogen bond, which usually stabilizes the R-state of hemoglobin, there is not likely to be an elevation in the concentration of R-state due to the unsteadiness of the hydrogen bond. The R-state would either remain constant or will get slow down.
Thus, the statement, that is, in hemoglobin Kansas, there is an elevation in the concentration of R-state and a reduction in the concentration of T-state is false.
If a disease is continually present in a population in small amounts, it is considered an endemic disease.
a. True
b. False
Answer:
TRUE
Explanation:
Endemic diseases are the diseases or infections that are persistently present in the population of a particular geographical area.
An endemic infection or disease does not increase at an exponential rate and also does not get eliminated entirely. Therefore, such an infection is constantly maintained without any external outputs and thus reaches the endemic steady state.
Why must reverse transcriptase be used to create a eukaryotic expression library?
a. reverse transcriptase is only used to create prokaryotic expression libraries
b. reverse transcriptase creates cDNA from mRNA in prokaryotes
c. reverse transcriptase ensures the gene is in the correct orientation within the expression vector to create protein
d. reverse transcriptase creates cDNA from mRNA because genes in eukaryotes have large numbers of non-coding regions.
e. no other enzymes are used to create expression libraries except restriction enzymes
Answer:
Option (d).
Explanation:
Genomic library may be defined as the total genome DNA of the organism. Reverse transcriptase is the enzyme used for the formation of DNA from the RNA molecule.
The eukaryotes DNA contain large number of sequences called introns that creates a problem in the construction of the eukaryote genomic library. This problem can be solved by creating the complementary DNA from the RNA molecule free from the introns.
Thus, the correct answer is option (d).
Define these terms: artery, arteriole, capillary bed, venule, and vein. Why do capillaries have sphincters?
Answer:
Artery: elastic vessels that carry blood away from the hearth at high pressures.Arteriole: subdivisions of arteries, they are thinner and have muscles that connect with the sympathetic nervous system. Capillary bed: it's a network of capillaries.Venule: Microscopic vessels that connect veins and capillaries.Vein: Blood vessels that carry blood back to the atria, they are less elastic than arteries.Capillaries are the smallest-diameter blood vessels that connect the smallest arterioles to the smallest venules, they have sphincters to control the blood distribution, based on the body's demands, the can relax or constrict so the blood can follow specific pathways to meet the tissue's necessities.
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The two major divisions of the nervous system are the __________
a. sympathetic and parasympathetic
b. mCNS and PNS
c. sensory and motor
d. voluntary and involuntary
Answer:
mCNS and PNS.
Explanation:
Nervous system of the body includes all the the nerves that carry message in the body from the spinal cord and brain . Nervous system has divided into two main branches.
The two main divisions of the nervous system are peripheral nervous system (PNS) and central nervous system (CNS). The central nervous system constitutes of the spinal cord and brain. The peripheral nervous system include the sensory receptor, motor nerves and sensory neurons.
Thus, the correct answer is option (b).
The two principal parts of the nervous system are the Central Nervous System (CNS) and the Peripheral Nervous System (PNS). The CNS is the main command system for the body, while the PNS is responsible for transmitting messages to various body parts.
Explanation:The two major divisions of the nervous system are the Central Nervous System (CNS) and the Peripheral Nervous System (PNS). The CNS includes the brain and spinal cord, and it is the primary command center for the body. The PNS includes all the nerves that branch out from the brain and spinal cord and extend to other parts of the body such as muscles and organs. These two divisions work together to transmit and process information to respond to stimuli from both internal and external environments.
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ATP molecules from Glycolysis + Krebs cycle are _______________
a. 12 ATP
b. 28 ATP
c. 32 STP
d. 4 ATP
Answer:
The correct answer will be option-D.
Explanation:
Cellular respiration proceeds in four stages: glycolysis, link reaction, Krebs cycle and electron transport chain. ATP is produced in each step along with other reducing equivalents which gets reduced during the electron transport chain to form ATP.
In the given question, only ATP molecules formed during both glycolysis and Krebs cycle will be 4 ATP as 2 ATP are produced in glycolysis and 2 ATP are produced in the Krebs cycle per two molecules of pyruvic acid.
Thus, option-D is the correct answer.
Select examples of energy changing forms. Select the THREE answers that are correct.
(A) From a high perch, a raptor dives toward its prey.
(B) An animal has stores of lipids in its fatty tissues.
(C) A green plant absorbs light to make sugar molecules.
(D) A seed remains dormant for an extended period.
(E) A human jogs down the street for exercise.
Final answer:
Examples of energy changing forms include a raptor converting potential to kinetic energy during a dive, a green plant transforming solar energy into chemical energy via photosynthesis, and a human converting chemical energy into kinetic energy while jogging.
Explanation:
Energy transformations are fundamental to biological processes and occur when energy changes from one form to another. Three examples of energy changing forms include:
(A) From a high perch, a raptor dives toward its prey: Potential energy stored due to the raptor's high position is transformed into kinetic energy as it dives towards its prey.(C) A green plant absorbs light to make sugar molecules: Solar energy is captured by photosynthetic organisms and converted into chemical energy in the form of glucose during the process of photosynthesis.(E) A human jogs down the street for exercise: Chemical energy stored in the body's molecules is converted into kinetic energy during physical activity.These instances illustrate how diverse organisms harness and convert energy to fuel their life functions, a concept centrally important to understanding biology.
When mutations exhibit complementation this means the mutations are located:
a. in the same gene
b. in the different genes
c. in between genes
d. in non-coding DNA
e. in introns
Answer:
The correct option is: b. in the different genes
Explanation:
In an organism, complementation is observed when the two strains with the different homozygous recessive mutations are mated or crossed to produce an offspring having wild-type phenotype.
Complementation is observed when the mutations are present in different genes.
Therefore, mutations are said to be complementary, if they are present in different genes.
Differentiate between parental ditype (PD), non-parental ditype (NPD), and tetratype (T).
Answer:
Parental ditype (PD):
Parental ditype may be defined as the teterad type of the ascus that contains two different genotypes. These genotypes are both of the parental type. These are non recombinant ascospores.
Non-parental ditype (NPD):
Non-parental ditype may be defined as the ascus spores that do not resemble with the parent genotype. These tetrad type are the recombinant type of the ascus.
Tetratype:
Tetratype are the spores that contains the four different genotypes. The two genotypes are the parental type and two are recombinant type. The tetratype indicates the single cross overs.
Final answer:
Parental ditype (PD), non-parental ditype (NPD), and tetratype (T) are three types of offspring resulting from a genetic cross. PD offspring exhibit the same allelic combination as their parents, NPD offspring have a different allele combination due to homologous recombination, and T offspring have both parental and non-parental alleles indicating a crossover event.
Explanation:
In genetics, parental ditype (PD), non-parental ditype (NPD), and tetratype (T) are three types of offspring resulting from a genetic cross. These terms are used in the context of linked genes and recombination during meiosis.
Parental ditype (PD) refers to offspring that exhibit the same allelic combination as their parents. Non-parental ditype (NPD) refers to progeny that exhibit a different allele combination compared to their parents due to homologous recombination. Lastly, tetratype (T) progeny exhibit both parental and non-parental alleles, indicating a crossover event occurred during meiosis.
What are: endocrine? Paracrine? Autocrine?
Answer:
Endocrine :
Endocrine cells may be defined as the cells that helps in the cell signalling in which the cells are located far apart. The product can shows slow effect but long lasting effect.
Paracrine:
Paracrine cells may be defined as the cells that are involved in the paracrine signalling. They acts on the cells that are located close to each other and generates quick response in body.
Autocrine :
Autocrine cells that are involved in the autocrine signalling affect their own cells. The target and signalling cells are same in autocrine. The pain sensations of the body are also regulated by autocrine signalling.
Final answer:
Endocrine, paracrine, and autocrine are types of cell signaling. Endocrine signaling travels long distances through bodily fluids, paracrine signaling acts locally between neighboring cells, and autocrine signaling occurs when a cell responds to its own signals.
Explanation:
In multicellular organisms, cells communicate through different types of signaling. The three main types are endocrine, paracrine, and autocrine signaling, each differing primarily in the distance the signal travels to reach the target cell.
Endocrine signaling involves hormones secreted into the extracellular fluid that then diffuse into the blood or lymph to travel to distant cells throughout the body. An example of endocrine signaling is the secretion of hormones by the pituitary gland.
Paracrine signaling involves signals, or paracrine factors, that act locally between cells that are close together. These signals move by diffusion through the extracellular matrix and are generally quickly degraded or removed to maintain localized effects. Histamine, responsible for the immune response in asthma, is an example of a paracrine signal.
Autocrine signaling occurs when a cell responds to signals it releases itself, with interleukin-1 (IL-1) being an instance of an autocrine involved in inflammatory responses. Autocrine signaling can also influence nearby similar cells and plays a key role in the early developmental processes and programmed cell death.
A planet is inhabited by creatures that reproduce with the same hereditary patterns seen in humans. Three phenotypic characters are height (T = tall, t = dwarf), head appendages (A = antennae, a = no antennae), and nose morphology (S = upturned snout, s = downturned snout). Since the creatures are not "intelligent," Earth scientists are able to do some controlled breeding experiments using various heterozygotes in testcrosses. For tall heterozygotes with antennae, the offspring are tall-antennae, 46; dwarf-antennae, 7; dwarf-no antennae, 42; tall-no antennae, 5. For heterozygotes with antennae and an upturned snout, the offspring are antennae-upturned snout, 47; antennae-downturned snout, 2; no antennae-downturned snout, 48; no antennae-upturned snout, 3. Calculate the recombination frequencies for both experiments.
Answer:
For the first experiment, the recombination frequency is shown below. This experiment comprises the cross between the Tall and the Antennae.
Tall-antennae - 46% - Expected
Dwarf-no antennae - 42% - Expected
Dwarf-antennae - 7% - Recombinant
Tall-no antennae - 5% - Recombinant
Total = 100%
For the recombinants, the recombination frequency is:
= 7 + 5 = 12%
Thus, the recombination frequency between the T and A genes is 12%.
For the second experiment, the cross takes place between the heterozygous antennae and the upturned snout. The results are shown below:
Antennae-upturned snout - 47% - Expected
No antennae-downward snout - 48 % - Expected
Antennae-downward snout - 2% - Recombinant
No antennae-upturned snout - 3% - Recombinant
Total = 100%
The recombinant frequency is = 2 + 3 = 5%
Thus, the recombination frequency between the A and S genes is 5%.
Answer:
For experiment 1, the recombinant frequecy is 12%
For experiment 2, the recombinant frequency is 5%
Explanation:
please look at the solution in the attached Word file
Plant cells differ from animal cells because only plant cells have _________
a. Cell wall and chloroplasts
b. Cell wall and centriole
c. Cell membrane and mitochondria
d. Lysosomes and central vacuole
Answer:
a. Cell wall and chloroplasts
Explanation:
The cell wall in plants facilitates the retention of the cell shape during over-hydration. The chloroplasts are organelles in plants that carry-out photosynthesis and produce glucose.
A common type of DNA damage from UV light results in:
a. bulky adducts
b. cross linked complementary strands
c. intrastrand crosslinks
d. free radicals
Answer:
C
Explanation:
The damage to DNA usually occurs where there are two consecutive thymine nucleotides on a DNA strand. The energy from the UV light causes the two dimers to form a cyclobutane pyrimidine structure. Proofreading and repair mechanism of DNA find it difficult to repair this kind of damage on DNA. During replication, therefore, DNA polymerase is unable to replicate this region hence leading to a mutation on the replicated strand at this local point.
People who misuse or overuse antibiotics may become resistant to them.
a. True
b. False
Answer:
True.
Explanation:
Antibiotics may be defined as the chemicals that are required to stop the growth and kill the other living organism. These antibiotics have been developed against bacteria, fungi and microorganisms.
The excess use of the antibiotics leads to the development of the resistant strain against that particular antibiotic. People should not overuse or misuse the antibiotics as they may become resistant and antibiotics will not effect the pathogens of that individual organism.
Thus, the correct answer is option (a).
Sauropod dinosaurs are more closely related to Aves than Ornithischian dinosaurs.
a. True
b. False
Answer:
TRUE
Explanation:
The Sauropods were the enormous herbivore dinosaurs that had a long neck and a tail, but the size of their head was relatively small. The fossil remnants of a previously existed unknown sauropod dinosaur species named 'Tataouinea hannibalis' were obtained from the rocks of the southern side of Tunisia.
From the fossil evidence, it was observed that a sizable opening was present in the ischium, which actually opens into a large air chamber. This observation supported the theory that considers the presence of abdominal air sacs in this type pf dinosaur species that are similar to the respiratory system of Aves (birds).
Thus, the Sauropods and Aves are closely related to one another.
Hence, the above statement is TRUE.
Blanching works to keep vegetables crisp and green when cooked because
a. PPOs are denatured at high temperature
b. Acids keep colors bright
c. Bases keep vegetables crisp
d. Ice water reverses Maillard reactions
Answer:
a. PPOs are denatured at high temperature
Explanation:
Polyphenol oxidase, PPO, is one of the most studied enzymes in the food industry as it is responsible for enzymatic browning reactions in fruits and vegetables. One of the reasons why its study is important is because commercially it is undesirable, since it modifies the sensory, nutritional and in general quality properties that impair the commercialization of a product.
The importance of controlling polyphenol oxidase is that it largely determines the quality and economic value of fruits and vegetables harvested, stored and processed. Bruising, chopping and other mechanical procedures damage the walls of fruits and vegetables which allows oxygen to penetrate, resulting in darkening or enzymatic browning reactions.
Enzymatic browning can be controlled through the use of chemical and physical methods, often used in combination. The commonly used physical methods are the reduction of temperature, oxygen and the use of modified atmospheres or coating films. The use of chemical methods will depend on what you want to inhibit, be it the enzyme, the substrate (oxygen or phenolic compounds) or the products.
Prokaryotes used to be classified into one group, but now they are classified in the Domains Bacteria and Archaea.
a. True
b. False
Answer:
True.
Explanation:
Three domains of life are prokarya, eukarya and archae. Prokaryotes are the organism that lacks the well developed nucleus and membrane bound cell organelle.
Earlier the prokaryotes are classified in the one group. But the prokaryotes are now further classified into the domains archaea and bacteria. As prkaryotic organism shows the similar characteristics with the archae and prokarya. To make the study more simpler, prokaryotes are splits into the domains of bacteria and archaea.
Thus, the answer is true.
What is homeostasis? help me to understand homeostasis ?
Answer:
Explanation:
The mechanism in which internal conditions of the body are properly maintained and regulated.
Which of these is not a feature that links "dinosaurs' to modern day extant birds"?
a. A furcula
b. Feathers
c. S-shaped neck
d. Nasal turbinates
e. The flight stroke
Answer:
The correct answer is option d. "Nasal turbinates".
Explanation:
Most mammals and modern day birds have nasal turbinates that perform two functions: improve the sense of smell by providing a wider area for airborne chemicals absorption and warm and moisten inhaled air while extracting heat and moisture during air exhalation. On the other hand, no evidence have been found that suggest that dinosaurs had nasal turbinates. Although most dinosaurs had nasal passages, they were too narrow and short to accommodate nasal turbinates.
Chorionic villus sampling is a prenatal test usually performed in the second trimester.
a. True
b. False
Answer:
b. False
Explanation:
Chorionic villus sampling test is used to determine the genetic disorder or chromosomal disorder in a fetus. Chorionic villus test is done by the PCR or by FISH. This test can take place usually performed in 10 to 12 weeks gestation i.e. first trimester, before amniocentesis. Chorionic villus can be removed by a needle. Pregnancy loss in CVS (Chorionic villus sampling) is 2-3 percent. So it is highly accurate.
Chorionic villus sampling is a prenatal test performed in the first trimester, specifically at 10-12 weeks of pregnancy, not in the second trimester. It is used to diagnose genetic abnormalities and determine the sex of the fetus, offering an earlier alternative to amniocentesis.
Explanation:The statement that chorionic villus sampling (CVS) is a prenatal test usually performed in the second trimester is false. CVS is an alternative method of prenatal diagnosis to amniocentesis and is typically performed earlier in pregnancy, between 10-12 weeks, during the first trimester. This procedure involves extracting a small amount of placental tissue, either through the abdominal wall or through the vagina, which provides cells for testing. The extracted cells can be used to diagnose over 100 genetic abnormalities, including chromosomal abnormalities like Down syndrome, enzymatic defects, and determining the sex of the fetus.
Unlike amniocentesis, which is done after 14-22 weeks and involves extracting amniotic fluid to obtain fetal cells for analysis, CVS allows for earlier detection and the possibility of a simpler process if an abortion is considered. Moms-to-be are also advised to avoid substances that can be fetotoxic as these can cross the placenta and affect the developing fetus, potentially leading to disorders like Fetal Alcohol Spectrum Disorders (FASD).
During bacterial transformation, DNA that enters a cell is not an intact chromosome; instead it consists of randomly generated fragments of chromosomal DNA. In a transformation where the donor DNA was from a bacterial strain that was a+ b+ c+ and the recipient was a b c, 55% of the cells that became a+ were also transformed to c+ But only 2% of the a+ cells were b+. Is gene b or c closer to gene a?
Answer:
Gene c is closer to a.
Explanation:
The process by which the bacteria take up the genetic material which is foreign from the environment is called as bacterial transformation and it is a type of horizontal gene transfer. When during transformation there is a simultaneous transfer of two or more genes then such type of transformation called co-transformation.According to the question, there is co-transformation occurring for both the genes a and b as well as for a and c, however, the frequency of cotransformation of a and c is higher (55%) than a and b (2%).A higher frequency of co-transformation indicates that the two genes are located more closely on the chromosome and hence, are usually transferred together, thus a and c are much closer as compared to a and b.You discover a new species and are given the task of describing and classifying it. Upon closer examination, you find that it has a single duct for reproductive, excretory, and defecatory material as well as a lack of true nipples. Which group are you sure this species does not belong to?
a. Mammalia
b. Metatheria
c. Prototheria
d. Synapsida
Answer:
a. Mammalia
Explanation:
Mammalia are the class species that have distinct systems and separate ducts for different activities like reproduction, excretory, and defecatory and moreover they have nipples to feed their young ones.
So, the above species which has a single duct for reproductive, excretory, and defecatory material as well as a lack of true nipples does not belong to Mammalia
In evolution, why is it important that individuals vary from each other?
A. Variation allows some individuals to do better than others, so those variations are selected for.
B. If variations or mutations are extreme enough, new species can result.
C. Variations are important because individuals have to change through time.
D. Variations are important because they're inherited.
E. Variation gives every individual an equal chance of surviving so they can be selected for.
Answer:
D. Variations are important because they're inherited.
Explanation:
A. False
Not all variations are just beneficial, there are variations that can be harmful, leading natural selection to eliminate these individuals.
B. False
Without some environmental pressure, that is, any change that drives the selection of an individual, mutation alone cannot generate a new individual. If this mutation is not selected as "beneficial" and is not passed on to future generations, this mutation will disappear in that individual.
C. False
Not necessarily. Genetic variations occur at random, so those species that survive are selected and able to adapt.
E. False
It does not give an equal chance of surviving.