Answer:
Voltage-gated calcium channels in the membrane open
Explanation:
When the presynaptic membrane of an axon terminal is depolarized, it induces the opening of voltage-gated calcium ion channels.
What is an Axon terminal?An Axon terminal may be defined as a region that is typically found at the end of a neuron after the termination of axons. This region is a small, spherical, bouton-like structure. It is also known as terminal boutons.
Once the voltage-gated calcium ion channels open, it allows the movement of calcium ions inside the cell. This entry of calcium ions provokes the fusion of synaptic vesicles with the membrane and finally the liberation of neurotransmitter molecules into the empty space which is known as the synaptic cleft.
Therefore, the opening of the voltage-gated calcium ion channel is the possible result of depolarizing the presynaptic membrane of an axon terminal.
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Final preparation for cell division is made during the cell life cycle subphase called G2. Select one: True False
Answer:false the final phase is M
Explanation:
Pinker (1997) and others have demonstrated that humans display an adaptive predisposition to make order out of disorder and sense out of nonsense. This tendency can account for __________.a. reliance on confirmation bias.
b. skepticism.c. the popularity of pseudoscience
d. belief perseverance.
Answer:
the answer is d
Explanation:
"Which of the following central nervous system cells regulate ions, regulate the uptake and/or breakdown of some neurotransmitters, and contribute to the formation of the blood-brain barrier?
A. microglia
B. neuroglia
C. oligodendrocytes
D. astrocytes"
Answer:D. astrocytes
Explanation:
glial cell are any of several types of cell that function primarily to support neurons its divided into four groups namely oligodendrocytes,
astrocytes, microglia, and ependymal cells. The astrocytes plays a key role in regulating ions, uptake and/or breakdown of some neurotransmitters, and contribute to the formation of the blood-brain barrier.
You are given an unknown organism to identify. It is unicellular and heterotrophic. It is motile, using many short extensions of the cytoplasm, each featuring the ring of 9 2 microtubule filament pattern. It has well-developed organelles and two nuclei, one large and one small. This organism is most likely to be a __________.A) radiolarians B) slime molds C) ciliates D) kinetoplastids E) foraminiferans
Answer:
This organism is most likely to be a ciliates.
Explanation:
Ciliates are small unicellular protozoans that contain hair like ciliated projection, called cilia.
They contain 2 different types of nucleus, one is called diploid micro nuclei, that are responsible for carrying germ line of a cell and another one is poliploid macro nuclei that helps to control cell regulation and expression of phenotype of the organism.
Clilates are motile and contain one or more prominent contractile vacuole where they store the food.
The axoneme contain 9 ring like outer doublets and 2 centrally located singlet microtubules, (9+2 axoneme)
The unidentified organism is most likely a ciliate, a heterotrophic unicellular organism, distinguished by well-developed organelles, two nuclei, and use of cilia for motility.
Explanation:The organism you are trying to identify is most likely a "ciliate." Ciliates are a type of unicellular (single-celled) protozoan under the phylum Ciliophora. They are characterized as heterotrophic (meaning they can't make their own food and therefore feed on organic substances), have well-developed organelles, and are known to have two types of nuclei - a single large macronucleus and one or more small micronuclei. Your description of the organism's motility (movement), specifically its use of short extensions of the cytoplasm with a 9+2 arrangement of microtubules, also aligns with ciliates because these are the characteristics of Cilia which are its mode of locomotion.
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It has been theorized that all of the modern continents on Earth were once part of a single continent. What scientific evidence is used to support this theory?
Answer:
Explanation:
At the end of the 1960s, several American researchers, including Jack E. Oliver and Bryan L. Isacks, had integrated this notion of seabed expansion with that of drifting continents and formulated the basis of the theory of Tectonic plates. According to the last hypothesis, the surface of the Earth, or lithosphere, is composed of a series of large and rigid plates that float in a soft layer (presumably partially molten) of the mantle known as asthenosphere. Oceanic ridges occur along some of the margins of the plate. In this case, the lithospheric plates separate and the material of the ascending mantle forms a new ocean floor along the posterior edges. As the plates move away from the flanks of the ridges, they carry the continents with them.
Based on all these factors, it can be assumed that the Americas joined Europe and Africa until approximately 190 million years ago, when a rift separated them along what is now the crest of the Mid-Atlantic Mountain Range. Later movements of the plate with an average of approximately 2 cm (0.8 inches) per year have brought the continents to their current position. It seems likely, although not yet proven, that this rupture of a single land mass and the drift of its fragments is simply the last of a series of similar events throughout geological time.
Answer:
Explanation:
In 1912 Alfred Wegener German meteorologist proposed the first truly detailed and comprehensive theory of continental drift and was single continent once.
He brought together a chunk of geologic and paleontological data, Alfred W. postulated that throughout most of geologic time there was just Pangea (only one continent).
The baby is actually pushed out and delivered in the _____ stage of labor. Question 2 choices Choice A.,first Choice B.,second Choice C.,third Choice D.,transition
Answer: Option B) Second
The baby is actually pushed out and delivered in the second stage of labour.
Explanation:
Of the three stages of labour during pregnancy, the second stage involves the release of the baby through the birth canal. it is during this stage that the baby is actually seen in flesh and can be carried by the birth attendants present.
Which species is least likely to become extinct? a. A mammal species that can live equally well on dry land and in fresh water b. A fish species that has hybridized with another species to produce infertile offspring c. A fish species found in all five of the Great Lakes d. A mammal species that feeds on a rare tropical orchid e. A fish species that feeds on only rare snails found in only one small river Submit
Answer:
a. A mammal species that can live equally well on dry land and in fresh water
Explanation:
Species need favorable conditions to thrive, reproduce, and survive going extinct from an environment. When such conditions change in an environment, and the species in that environment are unable to evolve along with such changes to become adapted to survive, they go extinct.
From the options given in the question, the least likely to become extinct is a mammal species that can live equally well on dry land and also in fresh water, as they would be well adapted to changes that occur in their habitat .
The mammal species that can live on both land and water is least likely to face extinction due to its adaptability and wide geographic range. Specialized species with very specific dietary needs or limited ranges are more at risk.
Explanation:The species least likely to become extinct is a mammal species that can live equally well on dry land and in freshwater. This species likely has a high level of adaptability to different habitats which makes them more resilient to environmental changes. Moreover, this adaptability gives them a broader geographic range, which, according to studies, reduces their chance of extinction compared to species with very small ranges. On the other hand, species like the one that feeds on a rare tropical orchid or the fish that feed on rare snails found in only one small river are highly specialized and their survival is critically tied to very specific and potentially vulnerable conditions which makes them more prone to extinction.
Also, the fish species that has hybridized with another species to produce infertile offspring faces a genetic dead-end, which does not bode well for its continued survival. Meanwhile, a fish species found in all five of the Great Lakes has a comparatively large range and is less likely to be categorized as rare, making extinction less probable, though localized threats could still pose significant risk.
Sensory receptors adjust their response rates on the basis of the average amount of stimuli received, resulting in _____.
Answer: Sensory adaptation
Explanation:
Sensory adaptation is the process whereby sensory receptors adjust their response rates on the basis of the average amount of stimuli received. Sensory adaptation refers to the decrease in sensitivity to a stimulus after continuous exposure to it. Depending on the stimulus, receptors may increase or decrease their ability to respond, and will develop an enhanced or diminished sensitivity to the stimulus. This can occur with all of our basic five senses: sight, hearing, smell, touch and taste.
1. __________ Completing tasks with correctness and attention to detail
2. ____________ A trait that results in complete, neat, and correct tasks
3. ____________ Sensitivity to other people's feelings and situations
4. ____________ A trait characterized by working independently and offering to help others
5. ____________ Recognition given by associations that an individual has met high standards and has demonstrated competency in given knowledge and tasks
6. ____________ Provides certification opportunities for medical transcriptionists
7. ____________ Believing that one's own race, ethnic group, and/or culture is superior to all other groups
8. ____________ The ability to speak and act considerately in various situations
9. ____________ Logically and systematically planning steps to accomplish a task
10. ____________ Finishing tasks on schedule, without complaining, and offering to assist others
Answer:
1. Accuracy
2. thoroughness
3. empathy
4. initiative
5. certification
6. AHDI (Association for Healthcare Documentation Integrity)
7. ethnocentrism
8. tact
9. problem-solving
10. dependability
Explanation:
1. Accuracy is the efficiency to complete a work with due diligence and micro checks at individual level
2. thoroughness is the ability to complete a work with accuracy, neatness and on time
3. empathy is the emotional intelligence that leads to sensing of others’ problem and situation
4. initiative is the first action taken by an individual on his/her own to change some thing
5. certification is the proof of excellence in any work.
6. AHDI (Association for Healthcare Documentation Integrity) is an association that provides medical certification
7. Ethnocentrism is the centric thought process of considering oneself greater than all in terms of social differences such as caste , creed, color etc
8. Tact is an aspect of an individual’s behaviour to act and speak efficiently irrespective of place, people and situation
9. problem-solving skill allows one to solve a problem strategically and step by step
10. dependability is the behavioral aspect of a person that makes him/her reliable and trustworthy
The student's question addresses personality traits, with a focus on conscientiousness, as defined by the Five Factor Model. Answers include conscientiousness, perfectionistic, agreeableness, and more, all of which relate to behaviors or characteristics associated with high conscientiousness.
Explanation:The student's question appears to be related to the study of personality traits, specifically the conscientiousness dimension from the Five Factor Model of personality. Here are the answers to the blanks based on the information provided:
Conscientiousness - Completing tasks with correctness and attention to detailPerfectionistic - A trait that results in complete, neat, and correct tasksAgreeableness - Sensitivity to other people's feelings and situationsSelf-discipline - A trait characterized by working independently and offering to help othersCertification - Recognition given by associations that an individual has met high standards and has demonstrated competency in given knowledge and tasksCannot be determined from the provided information - Provides certification opportunities for medical transcriptionistsEthnocentrism - Believing that one's own race, ethnic group, and/or culture is superior to all other groupsTactfulness - The ability to speak and act considerately in various situationsOrganized - Logically and systematically planning steps to accomplish a taskReliable - Finishing tasks on schedule, without complaining, and offering to assist others
The parts of the brain implicated in ADHD, such as the prefrontal cortex and the basal ganglia, feature large amounts of ____ activity. Many of the medications used to treat ADHD work by boosting the activity of this chemical.
Answer:
The parts of the brain implicated in ADHD, such as the prefrontal cortex and the basal ganglia, feature large amounts of __dopamine__ activity. Many of the medications used to treat ADHD work by boosting the activity of this chemical.
Explanation:
Attention deficit hyperactivity disorder (ADHD) is a medical condition in which patient brain has differences in brain development and activity. This can affect ability of sitting still, attention and self control. Moreover, children can be affected at home, at school and in friendships. (See attached Detailed info graph)
The parts of the brain implicated in ADHD, such as the prefrontal cortex and the basal ganglia, feature large amounts of dopamine activity. Many of the medications used to treat ADHD work by boosting the activity of this chemical.
The parts of the brain associated with ADHD exhibit significant dopamine activity, and treatments often aim to increase dopamine levels through medications. Medications like methylphenidate (Ritalin) and amphetamine with dextroamphetamine (Adderall) elevate dopamine levels, which can help in managing ADHD symptoms. These medications are effective because individuals with ADHD often show decreased dopamine activity in key brain regions associated with motivation and reward. This decrease in dopamine activity is thought to contribute to difficulties in impulse control and motivation which are hallmark symptoms of ADHD.
Hiking along a remote trail, Chen surprises a mother bear with her cubs. Chen's pupils dilate, his breathing rate increases, and his heart rate soars. Which part of the nervous system is MOST involved in this process?
Answer:
the sympathetic division of autonomic nervous system.
Explanation:
When the person experiences any stress or emergency conditions, the sympathetic division is activated. It triggers the release of stress hormones from the adrenal medulla. There is a series of physiological events called flight or fight response. It includes an increased breathing rate and increased heart rate to supply the extra oxygen as required under these conditions. The blood vessels supplying the blood to skeletal muscles are dilated and the pupils are dilated. All these responses prepare the person for emergency conditions such as facing a wild animal.
Final answer:
The sympathetic nervous system is responsible for Chen's fight-or-flight response, preparing his body to confront or escape the threat posed by the bear.
Explanation:
When Chen surprises a mother bear with her cubs and experiences a rapid physiological reaction, the part of the nervous system most involved in this process is the sympathetic nervous system. This system is activated during high-arousal, stressful situations and is responsible for the fight-or-flight response, preparing the body to either face a threat or escape to safety. The release of adrenaline and norepinephrine (noradrenaline) from the adrenal glands leads to a series of changes: pupil dilation, increased heart and breathing rates, perspiration, and tensing of muscles. The sympathetic nervous system effectively tells the body to "go, go, go," enabling rapid response to the perceived danger.
"Can you recognize the eight stages of meiosis based on the location and behavior of the chromosomes?"
Answer:
Four stages are of meiosis I and four stages for meiosis II.
Explanation:
Meiosis involves two sequential cellular divisions, that is , meiosis I and meiosis II. In meiosis I, homologous chromosomes pair and then separate.
Therefore, although the parent cell is diploid (containing two chromosome sets, one maternal and one paternal), each of the two daughter cells is haploid (containing only a single chromosome set).
In meiosis II, the sister chromatids separate. The four daughter cells that result are haploid
construct a chromosome map for genes a b c and d using the over data:A to D=25 percent; A to B=30 percent; C to D=15 percent; B to D=5 percent; B to C=20 percent
Answer:
B-D-C-A.
Explanation:
The chromosome map helps to understand the location of genes in the genome map. The distance between the genes can be used to locate the genes of chromosome.
The distance between the Band D is 5%. The B and D gene can be located with each other. Then gene C is located after D and the distance between them is 15%. This will give the distance between B and C is 20%. The gene A is located at the last position A and the distance between them 30%.
Thus, the correct answer is B-D-C-A.
Chromosome map: A-B-C-D. Distances: A-B > B-C > C-D. Recombination: A-D=25%, A-B=30%, C-D=15%, B-D=5%, B-C=20%.
A chromosome map, also known as a genetic map or linkage map, illustrates the relative positions of genes along a chromosome based on the frequency of recombination events between them. Recombination occurs during meiosis when genetic material is exchanged between homologous chromosomes.
Given the recombination percentages between genes A, B, C, and D, we can construct a chromosome map:
1. A to D = 25%: This indicates that 25% of the offspring exhibit recombination between genes A and D.
2. A to B = 30%: Similarly, 30% of the offspring exhibit recombination between genes A and B.
3. C to D = 15%: 15% of the offspring exhibit recombination between genes C and D.
4. B to D = 5%: Only 5% of the offspring exhibit recombination between genes B and D.
5. B to C = 20%: And 20% of the offspring exhibit recombination between genes B and C.
From these percentages, we can infer the relative distances between the genes. The order of the genes on the chromosome would be A - B - C - D. Additionally, we can deduce the map distances between adjacent genes.
For example, the distance between A and B would be greater than that between B and C, as indicated by the higher recombination percentage between A and B.
In the Gross Anatomy of Muscle Lab Manual, the triceps brachii is considered what in the action of the extension of an elbow?
Answer:
prime mover or agonist
Explanation:
The triceps muscles are responsible for performing the action on one side of the joint and hence they are termed as agonist while on the other hand the muscle which opposes this action is called an antagonist.
During elbow flexion, triceps causes the action by contracting and hence it acts as agonist. This muscle lies on the posterior side of Humerus and work as a third class lever.
Answer:
The correct answer is - agonist.
Explanation:
The triceps brachii is considered antagonist and agonist according to the action it perform at particular muscle action. The antagonist action is due to the presence on the opposite end of the the elbow joint and can restrict the elbow flexion.
If the case is about the active elbow extension as asked in the provided question it is agonist due to the support of action of the extension.
Thus, the correct answer is - agonist.
During knee extension, the shank (i.e., the segment between the ankle and the knee) undergoes what type of motion?
Answer:
The answer is angular.
Explanation:
The shank in humans, which is the body part between the ankle and the knee joint, is made up of distinct parts such as Tibia, Soleus Muscle, Gastrocnemius Muscle, The Achilles Tendon etc. and during the act of extending the knee in either direction, the shank undergoes an angular motion with the rest of the leg.
I hope this answer helps.
Identify what structures in a skeletal muscle will shorten in length during contraction of the muscle.
Answer:
Identify what structures in a skeletal muscle will shorten in length during contraction of the muscle.
The structure that shortens in length during muscle contraction is the sarcomere
Explanation:
Movement does occur in organism/animals as a result of muscle contraction which might give room for shorten of length as described by sarcomere
When helping a choking child, you should give ________. a. CPR b. Compressions c. Thrusts into the abdomen d. None of the above
Answer: The answer is C. Thrusts into the abdomen
Explanation: When a child is choking, it means an object is stuck in the trachea of that child. To help that child, wrap your arms around the child's waist above belly button while backing you and then pull inward and upward; thrusting up to five times. This will help to
squeeze the air out of the lungs and may dislodge the objects.
Also, you can give up to five blows at the back in between the shoulder blades. This help to create a strong vibration and pressure in the airway and consequently, dislodge the object.
What provides evidence of an increase in animal species at the same time that atmospheric oxygen concentrations increased?(1 point)
rust deposits
anaerobic organisms
fossil record
stromatolites
Answer:
stromatolites
Explanation:
"stromatolites is a calcareous mound built up of layers of lime-secreting cyanobacteria and trapped sediment, found in Precambrian rocks as the earliest known fossils, and still being formed in lagoons in Australasia"
Ancient cyanobacteria present in stromatolites are considered as key factor for the increased amount of oxygen in atmosphere. Furthermore, these were considered as first organisms to trap carbon dioxide and release oxygen by the process of photosynthesis.
Answer:fossil record
Explanation:
Archaeans Choose one: A. are the likely source of chloroplasts and mitochondria. B. are much more restricted in environment than organisms classified as either bacteria or eukarya. C. are prokaryotic like bacteria, but their gene expression machinery is more similar to eukaryotic organisms. D. look like pre-eukaryotic cells with a nucleus.
Answer:
The correct answer is B: "Archaeans are much more restricted in environment than organisms classified as either bacteria or eukarya".
Explanation:
The archaea domain is composed of prokaryotic unicellular microorganisms that lack a nucleus, nuclear membrane, and organelles, but they have a cell wall that protects the cell. They reproduce asexually.
Phenotypically, Archaea looks like Bacteria, being small and rounded, caned or spiriled-shaped, but they possess biochemical and genetic characteristics very different from bacteria.
Archaea are likely a source of mitochondria in eukaryotic cells. According to the endosymbiosis theory, these cells were free-living bacteria that were incorporated by another bigger cell, becoming the new organelle mitochondria. In the same way, Eukarya bacteria make a place for chloroplast.
These organisms are restricted to marginal habitats. They are capable of inhabiting in places with extreme temperature, salinity, acidity, or pH, among others.
Answer:
Answer is C.
Explanation:
Archaeans are prokaryotic , but their gene expression mechanism is more similar to that of eukaryotic organisms.
Archaeans are organisms that, like bacteria, lack a specific membrane around their genetic material. ... Unlike bacteria and Ukraine, Arachia has membranes containing branched hydrocarbon chains that are linked to glycerol via an ether linkage. Arachnoid cells do not contain peptidoglycan.
Check off all the choices that are valid MAJOR characteristics of organisms.
A
Take in materials from environment to make energy and release wastes
B
Complicated structural organization
C
Complicated chemical organization
Complicated organ organization
E Movement
F
Respond to other organisms
G
Grow and Develop
Respond to environment
Reproduce asexually
Communication
Answer:c
Explanation:
If a heterozygous woman without hemophilia had children with a man with hemophilia, what is the chance that their first child will have the disease?
Answer:
1/2
Explanation:
let the alleles of the heterozygous woman without hemophilia be = Xhx
And the alleles of the man with hemophilia be XhY
If both XhY × Xhx; we have:
Xh Y
Xh XhXh XhY
x Xhx xY
XhXh and XhY are affected by the diseases
Xhx is a carrier
xY is normal
∴ the probability(chance) that their first child will have the disease is 2/4 of the total offspring
=1/2
∴ the probability (chance) that their first child will have the disease is 1/2
According to Engelhardt, the phenomenon of bioethics should be understood as a late-modern intellectual undertaking that is about to "go aground on the reefs of postmodernity."A. TrueB. False
Answer: True
Explanation:
The bioethics can be defined as the ethical issues emerging from the advances in the biology and medicines.
It is concerned about the ethical questions that arises while performing any experiment. This is necessary to have a look on the experiments which is going to happen.
There are many types of research work going among life sciences, biotechnology. According to Engelhardt the phenomenon of the bioethics can be understood as modern intellectual undertaking the reefs of post modernity.
Final answer:
False, Bioethics is not about to 'go aground on the reefs of postmodernity' as stated by Engelhardt, emphasizing its importance in ethical considerations concerning advances in biology, technology, and medicine.
Explanation:
False
The statement is False. The phenomenon of bioethics, as described by Engelhardt, is not about to 'go aground on the reefs of postmodernity.' Bioethics is a field that studies ethical issues emerging from advances in biology, technology, and medicine, examining controversies such as abortion, euthanasia, and clinical trials.
Engelhardt's view highlights the importance of understanding bioethics within the context of scientific developments and societal considerations, emphasizing the ongoing nature of ethical debates in areas like environmental ethics and business ethics.
________ are molecules that form the core structure of cell membranes and micelles.
A) Phospholipids
B) Triglycerides
C) Steroids
D) Saturated fatty acids
E) Eicosanoids
Answer:
b
Explanation:
Phospholipids are the molecules that form the core structure of cell membranes and micelles due to their unique hydrophilic and hydrophobic properties.
Explanation:Phospholipids are the molecules that form the core structure of cell membranes and micelles. Phospholipids consist of a glycerol molecule, two fatty acids, and a phosphate group. The fatty acid chains are hydrophobic (water-repelling) and face inwards, inside the boundary, forming a hydrophobic core, while the phosphate group is hydrophilic (water-attracting) and faces outside, towards the water environment. This 'lipid bilayer' structure is integral to forming cell membranes, and is also what allows micelles (small lipid molecules that are arranged in a spherical form in aqueous solutions) to form.
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"A person who sits for hours on a long airplane flight will have problems will blood pooling below the knees. Why?"
Final answer:
Sitting for a long time on a long airplane flight can lead to blood pooling below the knees and increase the risk of deep vein thrombosis (DVT).
Explanation:
Sitting for hours on a long airplane flight can cause blood pooling below the knees due to a condition called deep vein thrombosis (DVT). DVT occurs when a blood clot forms in the deep veins, usually in the legs. When you sit for a long time, especially in cramped quarters, blood can pool in the deep veins of the legs, increasing the risk of a blood clot. Sitting for a long time on a long airplane flight can lead to blood pooling below the knees and increase the risk of deep vein thrombosis (DVT).
Dr. Smith is conducting research on the abilities of a man who experiences visual sensations while hearing sounds. Which data collection method should she use?
Answer:
Case study.
Explanation:
The research of psychology are mostly based on the observation and experience of the individual. The psychologist must follows the proper rules and regulation of the research.
Dr, Smith research is based especially on the case study. These case study includes the collection of the data from the multiple source. The reaction of the individual is measured on the different visual sensation and different sounds. Quantitative data collection is mostly used in the case study of the Dr. Smith.
Thus, the answer is case study.
A microbiologist inoculates a growth medium with 100 bacterial cells/ml. If the generation time of the species is 1 hour, and there is no lag phase, how long will it be before the culture contains more than 10,000 cells/ml?
Answer:
Seven hours
Explanation:
We were being told that;
A microbiologist inoculates a growth medium with 100 bacterial cells/ml
Also, the generation time of the species is 1 hour.
And more so no lag phase (i.e a period where the individual bacteria are maturing and not yet able to divide). There is nothing as such in the process given. Hence, this will make the replication more faster.
So , since the generation time is one hour and we are being given 100 bacterial cells/ml
∴
After 1 hour= replication of the bacterial cells would have been doubled to =200 bacterial cells
2nd hour = 400 bacterial cells
3rd hour = 800 bacterial cells
4th hour = 1600 bacterial cells
5th hour = 3200 bacterial cells
6th hour = 6400 bacterial cells
7th hour = 12800 bacterial cells
∴ We can see that at at the 7th hour, the culture has contained more than 10,000 cells/ml
If scientists are trying to study evolutionary relationships using the molecular clock, is it useful to study the genes that cause disease?
It is not possible to study the genes that cause disease using the molecular clock.
Explanation:
The molecular clock technique is an important tool in molecular systematic, the use of molecular genetics information to determine the correct scientific classification of organisms or to study variation in selective forces. A nice aspect of molecular clocks is that different genes evolve at different rates, which gives us flexibility to date events throughout the history of life" Hedges points out. Broadly speaking, the evolution of important genes occurs more slowly than that of genes with less vital functions.
In order to develop a molecular clock, one would need: a sequence of molecules, the rate at which changes occur in a type of molecule and how much total change has occurred in a type of molecule from different species.
Choose the true statement(s) about prokaryotic external appendages. To be marked correct, youll need to select all true statements, as there may be more than one correct answea.Pili allow for adhesion, movement, and aid in gene transfer through conjugation b.Fimbriae aid in gene transfer through conjugation. c.Flagella allow for motility. d.The glycocalyx promotes adhesion and interferes with phagocytosis.
Answer:
C) Flagella allow for motility; d) glycoclyx promotes adhesion and interferes with phagocytosis.
Explanation:
A) Pili; bacterial conjugation for reproduction
b) Fimbriae; Allow bacteria Adhesion to host cell
c) Flagella; Allow for motility
d) Glycocalyx;promotes adhesion and interferes with phagocytosis
Final answer:
The correct statements about prokaryotic external appendages are that a. Pili allows for adhesion, movement, and aid in gene transfer through conjugation; c. Flagella allows for motility; and d. The glycocalyx promotes adhesion and interferes with phagocytosis.
Explanation:
When examining the true statements about prokaryotic external appendages, we can identify the following:
Pili allow for adhesion and movement, and aid in gene transfer through conjugation.Flagella allow for motility.The glycocalyx promotes adhesion and interferes with phagocytosis.While fimbriae aid in attachment to surfaces and other cells, they are not typically involved in gene transfer through conjugation; this process is primarily facilitated by pili. Therefore, the statement concerning fimbriae aiding in gene transfer through conjugation is not true.
In animal cells, a certain anticancer drug disrupts microtubule formation by binding to microtubules and accelerating their assembly from the protein precursor, tubulin. This stops mitosis from proceeding. What specific process must this anticancer drug affect?
a. Chromatid assembly
b. Formation of the mitotic spindle
c. Formation of the centrioles
d. The S phase of the cell cycle
Answer:
b. Formation of the mitotic spindle
Explanation:
The mitotic spindle is made of microtubules. Microtubules are the polymers of tubulin proteins. The formation of the spindle starts in prophase. It is required to align the chromosomes at the cell's equator during metaphase. This is followed by splitting of centromere and separation of two sister chromatids to the opposite poles of the cell. The shortening of microtubules of the spindle during anaphase assist in the chromosome movement. Therefore, the mitotic spindle is required for cell division to occur. Anticancer drugs do not allow the formation of the spindle by interfering in the assembly of tubulin protein subunits.
Final answer:
The anticancer drug disrupts mitosis by affecting the formation of the mitotic spindle (option b), leading to the arrest of cell division and death of the cancer cells.
Explanation:
The anticancer drug in question affects the formation of the mitotic spindle, which is a crucial component during cell division. This spindle is responsible for sorting and separating chromosomes during mitosis.
When chemotherapy drugs like vincristine or colchicine bind to tubulin, they disrupt the assembly and disassembly of microtubules which constitute the mitotic spindle.
Consequently, without a functional spindle, the chromosomes cannot be properly organized and segregated, leading to the arrest of mitosis and the eventual death of the cell. This is particularly effective against cancer cells, as it stops their rapid and uncontrolled division.
Blood is accelerated from rest to a speed of 33.0 cm/s in a distance of 1.73 cm by the left ventricle of the heart. Determine the magnitude of the acceleration a of the blood.
Final answer:
To calculate the acceleration of the blood, the kinematic equation[tex]a = (v^2 - u^2) / (2 * s)[/tex]is used, considering the final speed is 30.0 cm/s, initial speed is 0 cm/s, and distance is 1.80 cm, which gives an acceleration of [tex]250 cm/s^2.[/tex]
Explanation:
The question asks about determining the magnitude of acceleration that the blood experiences when accelerated by the left ventricle of the heart from rest to a certain speed across a particular distance. To calculate this, we can use one of the kinematic equations that relate acceleration, final velocity, initial velocity, and displacement:
[tex]a = (v^2 - u^2) / (2 * s)[/tex]
where v is the final velocity (30.0 cm/s), u is the initial velocity (0 cm/s as the blood starts from rest), and s is the distance covered (1.80 cm).
Plugging the values into the equation:
[tex]a = (30.0 cm/s)^2 / (2 * 1.80 cm)[/tex]
[tex]a = 900 cm^2/s^2 / 3.60 cm[/tex]
[tex]a = 250 cm/s^2[/tex]
Therefore, the magnitude of the acceleration of the blood is [tex]250 cm/s^2.[/tex]