A biologist ground up some plant leaf cells and then centrifuged the mixture to fractionate the organelles. Organelles in one of the heavier fractions could produce ATP in the light, while organelles in the lighter fraction could produce ATP in the dark. The heavier and lighter fractions are most likely to contain, respectively
Answer:
Chloroplast and mitochondria respectively
Explanation:
The chloroplast is the organelle wherein ATP is produced by the process of photophosphorylation during the light-dependent phase of photosynthesis. The transfer of electrons from PSII to PSI via electron transport chain generates a proton concentration gradient across the thylakoid membrane which in turn drives the process of ATP synthesis.
Mitochondria can produce ATP in the absence of light by the process of oxidative phosphorylation. Oxidation of NADH and FADH2 via electron transport chain generates a proton concentration gradient across the inner membrane of mitochondria which in turn drives the process of ATP synthesis
If a solution is hypotonic, it will cause the cell to swell.a. No, the ions will evenly distribute themselves between the surrounding solution and the inside of the cell. b. Yes, the solution is hypotonic, causing the cell to burst. c. No, the solution is isotonic. d. Yes, the solution is hypertonic, causing the cell to swell.
Answer: Option B) Yes, the solution is hypotonic, causing the cell to burst.
Explanation:
Because a hypotonic solution is of lower concentration to its surrounding, a cell placed in such solution absorbs the content of the solution, swells and then burst due to the uncontrolled inflow of the solution through its cell membrane.
Thus, the answer is Yes, the solution is hypotonic and cause the cell to burst.
Understand the terms genome, chromosome, gene, replication fork, Okazaki fragment, genotype, phenotype, codon, anticodon, promoter, intron, exon . Know the relative sizes of plasmids, bacterial and eukaryotic genomes. Know the general structure of the bases of RNA and DNA, including which are purines and which are pyrimidines. Understand the base pairing rules and how the bases are held together. Know what an antiparallel arrangement is. Know the difference between replication, transcription and translation. Know the function of the enzymes helicase, primase, DNA polymerase III, DNA polymerase I, RNA polymerase, ligase and gyrase. Know the differences between leading and lagging strand synthesis. Understand the relationship between DNA sequence and protein function. Know the difference between RNA and DNA and the different types of each found in the cell. Understand the process of protein synthesis and how to read the genetic code. Know how transcription and translation differ between eukaryotes and prokaryotes. Be able to compare an inducible and repressible operon and know the examples covered in class Know what a mutation is and how they arise. Know the different type of mutations including point, missense, nonsense, silent, back, substitution and frameshift. Know which types of mutations are most serious and why. Understand genetic recombination in bacteria including conjugation, transformation and transduction.
Answer:
Molecular biology aims to study the processes that are carried out in living beings from a molecular point of view
Explanation:
-Genoma: A set of genes contained in chromosomes, can be interpreted as the totality of the genetic material that an organism or a species has
-Chromosome: Each of the highly organized structures, formed by DNA and proteins, and contains most of the genetic information of a living being
-Gen: Molecular unit of genetic inheritance, where genetic information is stored and can be transmitted to the offspring
- Replication fork: Joint between two strands of DNA when it is self-replicating. Each of the DNA strands serve as a template for the synthesis of the new DNA
-Okazaki fragment: Short strands of DNA newly synthesized in the discontinuous strand. They are synthesized in the 5 '→ 3' direction from RNA primers that are later eliminated
-Genotype: Genetic information that an organism has, in the form of DNA
-Fenotype: Expression of the genotype according to a specific environment. They include both physical and behavioral traits
-Codon: Three nucleotide sequence of DNA or RNA corresponding to a specific parameter
-Anticodon: Three nucleotide sequence complementary to a sequence of three other nucleotides found in messenger RNA
-Promotor: DNA section that controls the initiation of RNA transcription
-Intrón: Region of the DNA that is part of the primary transcription of RNA and are removed from the mature transcript, before its translation
-Exon: Portion of gene encoding amino acids
-The modified plasmid size from 1 to more than 1000 kilograms of bases
-The size of the bacterial genome ranges from 0.58 megabases to 10 Mb in several species of cyanobacteria, with the exception of Bacillus megaterium, which has a 30 Mb genome
-The size of the eukaryotic genome is very variable, for example, the smallest sequenced is that of Guillardia theta, of only 0.55 Mb, yeast (1.2 Mb) to amoeba (686,000 Mb).
-In the DNA, the purines are adenine (A) and guanine (G). The pyrimidines are thymine (T) and cytosine (C). In the case of RNA, the purines are A and G and the pyrimidines are C and U (uracil)
-Transcription involves the copy of DNA in RNA. This is the process of gene expression, in which genes are converted into proteins. DNA replication is the process of copying DNA into a cell so that there are two equal copies. As a result, two double chain propellers are obtained, two exact copies. Translation is the process of translating the sequence of a messenger RNA molecule into an amino acid sequence during protein synthesis.
-Helicase breaks the hydrogen bonds that bind the nitrogen bases, causing other enzymes to copy the DNA sequence. The primase synthesizes small fragments of RNA on the lagging chain in DNA replication, of about 10 nucleotides, called primers. DNA polymerase III performs the replicative process, its function is the synthesis of DNA. It has review activity, 3’-5 ’exonuclease. DNA polymerase I has three activities. It has polymerase activity, synthesis in the 5’-3 ’direction. A 3’5 ’exonuclease activity, erroneous nucleotide removal, and a 5’-3’ exonuclease activity, which from a nick resynthesizes a portion of DNA by removing the existing one. This enzyme does not carry out the replication process. RNA polymerase is capable of using ribonucleotides to synthesize RNA from a DNA sequence that serves as a template. Ligase catalyzes the binding of two molecules from the formation of covalent bonds accompanied by the hydrolysis of ATP
What did Wallace conclude from observing that the bones in manatee flippers look similar to the bones in a human arm and hand? What did Wallace conclude from observing that the bones in manatee flippers look similar to the bones in a human arm and hand? Manatee finger bones must have an important function, necessary for the animal’s survival. Manatees were specially created in their current form, including the arm and finger bones inside their flippers. Manatees use their flippers like humans use their hands. Manatees’ arm and finger bones are evidence that manatees share a common ancestor with land mammals.
Answer:
Manatees' arm and finger bones are evidence that manatees share a common ancestor with land mammals.
Explanation:
Manatees were aquatic mammals while humans are mainly land mammals. However, the presence of body parts or organs having similar structures in manatees and humans suggests that these two species of mammals shared a common ancestor. The arms and finger bones were also present in their common ancestors.
Humans and manatees diverged into different directions to become adapted to terrestrial and aquatic lifestyle respectively. Therefore, the forelimbs developed into flippers in manatees while the same do the function of holding objects in humans. These are called homologous structures.
The correct conclusion that Wallace drew from observing the similarity between the bones in manatee flippers and the bones in a human arm and hand is that manatees' arm and finger bones are evidence that manatees share a common ancestor with land mammals.
The observation of similar bone structures in the flippers of manatees and the arms and hands of humans suggests that these two species have a common evolutionary origin. This is consistent with the theory of evolution, which posits that species evolve over time and that similarities in anatomy can be attributed to shared ancestry. The presence of bones that correspond to fingers within the manatee's flippers indicates that their ancestors may have had limbs adapted for life on land, which over time have been modified to suit an aquatic lifestyle. This kind of structural homology is often used as evidence for the process of natural selection and the descent of species from common ancestors.
The other options provided do not align as closely with the evidence from the observed similarities:
- Manatee finger bones must have an important function, necessary for the animal’s survival: While this statement may be true, it does not directly address the evolutionary implications of the bone structure similarities.
- Manatees were specially created in their current form, including the arm and finger bones inside their flippers: This conclusion aligns with creationist views rather than scientific evidence of evolution.
- Manatees use their flippers like humans use their hands: This statement is not necessarily true and does not explain the reason for the bone structure similarities from an evolutionary perspective.
Therefore, the most scientifically supported conclusion is that the similar bones in manatee flippers and human arms and hands are evidence of a common ancestor, reflecting the process of evolutionary adaptation and divergence from a shared lineage.
What effect does epinephrine/norepinephrine have on the alpha receptors of the iris of the eye or the skeletal muscle vasculature?
Answer: When norepinephrine binds to alpha receptors of the iris of the eye, it causes contraction of the ciliary muscles of the eye which brings about pupil dilation.
Stimulation of alpha receptors of the smooth muscle vasculature results in vasoconstriction of blood vessels.
Explanation: Alpha receptors are adrenergic receptors that respond to norepinephrine. They are subdivided into two (2) types:
Alpha 1, found in smooth muscle heart, liver, pregnant uterus, male sexual organs and blood vessels, with effects including vasoconstriction, intestinal relaxation, uterine contraction and papillary dilation.
Alpha 2, found in platelets, vascular smooth muscle, nerve termini and pancreatic islets, with effects including platelet aggregation, vasoconstriction and inhibition of norepinephrine release and of insulin secretion.
A biological theorist studies a psychological disorder through the interconnectivity of an entire network of brain structures. This shows the recent belief that the key to psychological disorders lies in:
Answer:
Hormonal Imbalances generated by irregular stimulus or impulses of brain
Explanation:
According to the recent research, most of the patients with serious psychological disorders have severe imbalances of hormones in their body. Most of them also have a history of trauma to head and spine. When a part of brain gets damaged, it may become dead (under-active) or may become overactive and hormonal instability have serious psychological complications.
The biological perspective suggests psychological disorders are rooted in biological phenomena such as neurotransmitter imbalances and genetic factors. The bio-psycho-social model complements this by considering psychological stressors and social factors in the development of mental illnesses, highlighting an integrated approach to understanding and treating these conditions.
Explanation:The biological theorist's approach to studying psychological disorders through brain structure interconnectivity aligns with current beliefs in the biological perspective of psychological disorders. This perspective posits that conditions like depression and schizophrenia are associated with neurotransmitter imbalances and genetic factors, along with abnormalities in brain structure and function. This emphasizes the importance of biological bases in understanding psychological disorders. Furthermore, the bio-psycho-social model complements this by suggesting an integrated approach, acknowledging that while biological factors set the stage for disorders, psychological stressors and social factors also play vital roles in triggering and shaping these conditions. This comprehensive model encompasses genetic predispositions, stress responses, negative thinking patterns, hormones, neurotransmitter function, and sociocultural influences, thereby providing a more holistic understanding of mental illness.
To cite an example, schizophrenia's etiology includes genetic vulnerability paired with environmental and psychosocial stresses. Other mood and anxiety disorders also arise from a complex interplay between biological predispositions such as hormones, individual thought processes, and social interactions. Thus, the bio-psycho-social model serves as a framework for assessing the causes and treatments of disorders, illustrating the intricate network of factors that contribute to mental health conditions.
You are studying two traits in fruit flies:
Eye color where there are two colors, brown and red, and wing shape where there are straight and curled phenotypes.
You mate two flies that are heterozygous for the genes that control both of these traits and get the following phenotypes in the following ratio:
9 red and straight; 3 red and curled; 3 brown and straight; 1 brown and curled.
Considering these traits, which alleles separated at which stages of meiosis?
a. red segregated from brown in meiosis I, and straight segregated from curled in meiosis II
b. red segregated from brown in meiosis II, and straight segregated from curled in meiosis I
c. red segregated from brown in meiosis I, and straight segregated from curled in meiosis I
d. red segregated from brown in meiosis II, and straight segregated from curled in meiosis II
e. red segregated from straight in meiosis I, and brown segregated from curled in meiosis II
Answer:
C
Explanation:
This is a typical dihybrid cross involving two genes; one coding for eye color and the other for seed shape. According to Mendel, for each trait, an organism (fruitfly in this case) receives two forms of a gene called ALLELE, from each parent. These two alleles get separated into gametes in an equal frequency during meiosis.
In this case of heterozygous parents i.e. they have a combination of the variant genes (alleles) that controls both traits, each parent has a brown and red allele for one gene and a straight and curled allele for the other gene. These two alleles for each gene were each received from the male and female parent.
In meiosis I, homologous chromosomes (similar but non-identical chromosomes received from each parent) separate. Hence, each allele of all the genes separates into gametes. Both red and brown allele separates into different gametes, while straight and curled alleles also separate into different gametes. This happens in a way that each gamete must contain one allele of each gene. Both occurs in meiosis I because the alleles for the different traits are borne on homologous chromosomes, which separate in the Anaphase stage of meiosis I.
If a pair of homologous chromosomes fails to separate during anaphase of meiosis I, what will be the chromosome number of the four resulting gametes with respect to the normal haploid number (n)?
If a pair of homologous chromosomes fails to separate during anaphase of meiosis I, what will be the chromosome number of the four resulting gametes with respect to the normal haploid number (n)?
a) n + 1; n + 1; n - 1; n - 1
b) n + 1; n + 1; n; n
c) n + 1; n - 1; n; n
d) n + 1; n - 1; n - 1; n - 1
Answer:
a) n + 1; n + 1; n - 1; n - 1
Explanation:
Separation of homologous chromosomes occurs during anaphase-I of meiosis. This event reduces the chromosome number from 2n to "n" in the daughter cells. If a pair of homologous chromosomes do not separate during anaphase-I, both the homologous chromosomes of that pair would be present in one daughter cell of the meiosis-I (n+1) while the other daughter cell would lack that chromosome (n-1).
Meiosis-II would maintain this chromosome number. Therefore, two gametes will have one extra chromosome (n+1) while the two gametes would lack one chromosome (n-1).
Answer:
a) n + 1; n + 1; n - 1; n - 1
Explanation:
You begin your investigation by examining the chromosomes of the two athletes with a karyotype analysis (a procedure that isolates an entire set of chromosomes when they are condensed for mitosis). the results are shown below, along with control samples from a normal female and a normal male.
The barr bodies will be present in only female control, and absent in all the rest. While SRY gene will be absent in only the female control and present in all rest.
Explanation:The Barr bodies are the dark bodies that are seen inside the nucleus of WBCs in females. These are actually the condensed X chromosomes which is seen in females as they have 2 X chromosomes and one of them remain silent and is seen as Barr bodies.
The SRY gene is actually the TDF gene or Testis Determining factor which secretes a protein called the Sex determining Region Y protein. Its present in the Y chromosome of males and one of the very few functional genes of Y chromosome.
In the given Karyotype of the 2 athletes, we can see that both the athletes are males as they are having one X chromosome and one Y chromosome. So they are males. And hence, both of them will be having the SRY gene and in both of them, Bare bodies will be absent.
A 53-year-old man presents with inability to concentrate, itching in his fingers and toes, elevated blood pressure, and unexplained weight loss. He is diagnosed with primary polycythemia. The primary goal of his treatment will be to:
Answer:
A 53-year-old man presents with inability to concentrate, itching in his fingers and toes, elevated blood pressure, and unexplained weight loss. He is diagnosed with primary polycythemia. The primary goal of his treatment will be to: total reduction of blood production which would help to solve other issues
Explanation:
polycythemia is a condition that entails the high production of the erythrocytes which is detrimental to good health condition. Food that increases blood production such as proteinous food like beans, egg, milk e.t.c would be avoided in order to maintain normal blood production
The main treatment objective for primary polycythemia is to lower the elevated hematocrit and blood viscosity, reducing blood pressure and improving symptoms.
The primary goal of treatment for a 53-year-old man diagnosed with primary polycythemia would be to reduce the elevated hematocrit and viscosity of the blood to decrease blood pressure and alleviate symptoms such as difficulty concentrating and itching in the fingers and toes. Polycythemia vera, a bone marrow disease, results in excessive production of immature erythrocytes, which can lead to complications such as raised blood pressure due to increased blood viscosity. Treatment typically involves phlebotomy to reduce blood volume and medications to lower the risk of blood clots. In some cases, chemotherapy or radiopharmaceuticals may be used to suppress the overactive bone marrow.
While serving in Iraq with the U.S. Army, Sergeant Carlos Rogers had an improvised explosive device detonate under his vehicle and cause a concussion. Years later, he's finding that he's having problems with his short-term memory, mood swings, and changes to his personality. His psychiatrist orders an MRI scan to determine if the problems are ______ based.
Answer:
Biologically based
Explanation:
Magnetic Resonance Imaging (MRI) is a medical equipment/device used to diagnose the internal organs of the brain. It is something which is not recommended in a psychiatric therapy. Thus, if MRI is recommended by a psychiatrist, it simply means that the psychiatrist want to get assured that the problems related with the brain are not due to any biological cause.
Which is often more predictive of the client's success than the characteristics of his or her illness?
Answer:
Living environment.
Explanation:
The illness may be defined as any kind of disease or sickness that affects the normal body condition. Bacteria, virus and other disease causing organisms can cause illness.
Both the external and internal environmental factors might responsible for the illness. The positive and healthy living environment is important to keep the individual's healthy and free from any illness. The internal living environment represents the physiological condition of the body and the external living environment represents the physical condition like proper sanitation, proper hygiene is important for the client success.
Thus, the answer is living environment.
A biologist discovers two populations of wolf spiders whose members appear identical. Members of one
population are found in the leaf litter deep within the woods. Members of the other population are found in the
grass at the edge of the woods. The biologist decides to designate the members of the two populations as two
separate species. Which species concept is this biologist most closely utilizing?
A) ecological
B) biological
C) morphological
D) phylogenetic
a
Answer:
Ecological species concept
Explanation:
A species is a group of living organism consisting of individuals that can interbreed.
There are different types of species concepts. For instance, Ecological species concept defines species are a group of individuals that share the same ecological niche.
Therefore, when the biologist did not consider the physical similarities of the wolf spiders rather their ecological niche to group them.
I shows he utilized the ecological species concept.
Based on the anatomical and physiological differences between an infant and an adult, which finding would suggest respiratory distress in an infant, but would be less likely to be observed in an adult
Answer: Excessive movements of the walls of the abdomen
Basically babies belly breathe, that is they undergo abdominal pattern of respiration( instead of the abdomino- thoracic pattern in adult), through their abdomen.
This is because, their thoracic walls are not fully functional to undergo the normal adult mechanisms of breathing.
The ribs are short in length due to incomplete ossification. They curve out wards, at low angle, their sternum, is shaped horizontally.
These features reduce the activities of the inter coastal muscles and the thoracic cage in the mechanism of infants breathing,compare to the long ribs, obliquely shaped rib cage, with lower sternum of adult which permit the abdominal-thoracic breathing pattern.
Therefore ,when the diaphragm distends during breathing ,its movement pushes the organs of the abdomen down; because infants have rapid respiratory rates, the distends created rapid expansion and contraction of the walls of the abdomen to gain enough abdominal pressure.
This together with the movement of organs of the abdomen from the pathways of diaphragm created the excessive movements of the abdominal walls. This rapid abdominal wall movements creates discomfort and distress for the infant during this mechanisms.
Explanation:
Final answer:
D. Excessive abdominal wall motion is a sign of respiratory distress in infants since they rely more on their diaphragm for breathing compared to adults.
Explanation:
Based on the anatomical and physiological differences between an infant and an adult, excessive abdominal wall motion would suggest respiratory distress in an infant but would be less likely to be observed in an adult. In infants, particularly those with Respiratory Distress Syndrome (RDS), the underdeveloped intercostal muscles and the reliance on the diaphragm for breathing make abdominal movement more pronounced when they experience respiratory distress. Adults typically have stronger chest muscles, allowing them to rely less on abdominal muscles for breathing, making excessive abdominal wall motion less common in adult respiratory distress.
The __________ pathway is used by plants that thrive in high temperate conditions, such as sugarcane. Select one: a. C2 b. C3 c. C4 d. CAM
Answer:
C4
Explanation:
Plants present under the conditions of higher temperatures have several adaptations to reduce water loss. One such adaptation is the C4 photosynthetic pathway. In C4 pathways, plants perform the primary fixation of CO2 into C4 acids in mesophyll cells. These C4 acids are then transported to the bundle sheath cells where they are being decarboxylated to release CO2. The released CO2 enters into Calvin cycle and glucose is produced while the C3 acids are transported back to the mesophyll cells to continue the process.
In these plants, RuBisCo is present in bundle sheath cells and the higher concentration of CO2 around this enzyme increases the photosynthetic efficiency by reducing photorespiration. Thereby, these plants have a higher photosynthetic rate and do not need to open stomata more to support photosynthesis.
Polymerase chain reaction (PCR) is a common laboratory technique used to make many copies of a particular region of DNA. PCR is usually used to create enough of the target DNA. DNA replication in organisms requires a DNA polymerase to create new strands of DNA from existing templates and this is needed in PCR. How does PCR separate the DNA strands to prepare for DNA replication?
Answer:
The PCR machine consist of a thermal cycle that increases and decreases the temperature of the sample. When the temperature is increased, the double-stranded DNA template mixture is denatured or separated into single strands.
Pertaining to natural selection, this is a measure of the relative reproductive success of individuals. It can be measured by an individual's genetic contribution to the next generation compared with that of other individuals. A. natural selection B. traits C. selective pressures D. fitness
Answer:
The correct answer is D. fitness
Explanation:
The ability of an organism to survive up to reproductive age and produce its offspring is called biological fitness. The fitness of any individual can be measured by the genetic contribution of that individual into the next generation.
This means that the higher the number of offspring produced by any individual higher would be its biological fitness. By averaging the fitness of population members the fitness of a population can be calculated. So fitness is the correct answer.
The Hardy-Weinberg principle is written as an equation: p2 + 2pq +q2 = 1. What does the q represent?
A.
frequency of the dominant allele
B.
the size of the gene pool
C.
frequency of the recessive allele
D.
the size of the population
Answer:
I think its D
Explanation:
A researcher tests whether dosage level of some drug (low, high) causes significant differences in health. What is this type of study?
Answer:
If a researcher is studying on the dosage level of some drugs, He is doing a PHARMACOLOGICAL studies
Explanation:
Pharmacology is simply the study of how drugs interact with the body and how the body responds to the drugs. It is simply the study of what drugs does to a body and what a body does to the same drug. Pharmacology is divided into two parts ; Pharmacodynamic and Pharmacokinetics
The first-pass effect occurs with orally administered drugs because a. their absorption is slowed by food. b. drug absorbed into the bloodstream from the stomach goes to the liver on the way to the general circulation. c. a drug must first survive the acidic environment of the stomach. d. salivary enzymes in the mouth begin the process of metabolism.
Answer: Option B
Explanation:
The first -pass effect occurs with the orally passed drugs. The drugs that are taken orally moves to different parts of the body.
The drug administered inside the body is reduced in concentration before it reaches the systematic circulation of the body.
It can be defined as the loss of fraction of drug during the process of absorption which is related to liver and gut wall.
Hence, the correct answer is option B
____ cells are required for almost all parts of the innate and adaptive immune responses to function properly.
Answer:
Cells
Explanation:
Meiosis results in independent assortment of maternal and paternal chromosomes. If n=3n=3 for a given organism, and there is no crossing over, what is the chance that a gamete will receive only paternal chromosomes?
Answer:
1/8
Explanation:
In genetics as a whole there are few topics that impinge on human affairs quite so directly as this one. Foremost is the fact that a large proportion of genetically determined ill health in humans is caused by abnormal chromosome numbers. Additionally, manipulation of chromosome number is routinely used by breeders to improve agriculturally important species.
All strains of human papillomavirus (HPV) are capable of integrating their double-stranded DNA viral genome into host basal cells while waiting for keratinocyte differentiation before initiating viral replication for virion shedding. As a consequence of the integrated genome, HPV strains that more readily transform host cells are more likely to cause an increased expression of viral ________.a. tumor suppressor genes.
b. oncogenes.
c. lytic genes.
d. lysogeny genes.
Answer:
Option B, Oncogenes
Explanation:
Human papillomavirus (HPV) is a virus that has double stranded DNA and it also has a tendency of entering into the cytoplasm of the host cell without un-coating itself. Since it is a virus, it replicates with in the nucleus of the host DNA polymerase until the basal cells differentiate into keratinocytes. Keratinocytes are keratin producing epidermal cells which hinders the transmission of HPV hence its shedding its essential for transmission of HPV into new host. Over-shedding leads to abnormal expression of HPV due to change in normal expression pattern.
Hence, option B is correct
Cellular signaling follows a cascade of events and has multiple points of regulation. Which of the following could be a reason(s) why a signalling cascade is interrupted, or turned 'off', once it has been turned 'on'?
A. The ligand is prevented from reaching the binding site.
B. A chemical modification occurred on serine, threonine, or tyrosine side chains to turn on/off proteins.
C. A protein gets tagged with an ubiqutin group and gets degraded.
D. A G-binding protein binds to a GTP molecule.
E. A, B and C only.
F. A and B only.
G. All of the above.
Answer:
A,B and c only
Explanation:
Cell signalling is the transfer of information from one cell to another.
It is important for growth, development and immunity.
An error can lead to serious problems such as diabetes and cancer.
Therefore this process is highly regulated. A signal in the cascade can be interrupted or turned off when;
The ligand is prevented from reaching the binding sitesA chemical modification occurred on serine, threonine, or tyrosine side chains to turn on/off proteins. A protein gets tagged with an ubiqutin group and gets degraded.The proposal that the global environment has been profoundly changed since life appeared on Earth, and that the presence of living organism's changes the environment to improve living conditions is associated with _________.
Answer: Gaia hypothesis
Explanation: Gaia hypothesis conceived by a chemist James E. Lovelock and biologist Lynn Margulis was introduced in the early 1970s.
They hypothesis states that Earth and its biological systems behave as a huge single entity and that this entity has closely controlled self-regulatory negative feedback loops that keep the conditions on the planet within boundaries that are favorable to life.
This hypothesis has it that living organisms interact with their inorganic environment to form a working and self-regulating, complex system which makes life and conditions for life on earth to continue favourably and perpetually
How does radiometric dating provide support for the theory of evolution by natural selection?
Answer:
By establishing linking features of fossils in different age brackets through radioactive dating
Explanation:
Radioactive dating estimates the age of fossils and rock. Fossils are remains of living organisms that are primarily found in the sedimentary rocks. Carbon dating is used to determine the age of the fossils that are not older than 50 thousand years.
For fossils older than that uranium dating is used. Based on the age estimation of fossils, fossils belonging to the same age bracket are grouped from the oldest time to the most recent time thereby marking the common characteristics of different fossils at each age brackets. In this way radioactive dating helps the scientist in establishing evolutionary links.
Radiometric dating supports the theory of evolution by natural selection by providing evidence for the timeline of life on Earth, enabling scientists to study the sequence in which different species have appeared or disappeared. Also, it evidences the concept of deep time, essential for the concept of gradual evolutionary change.
Explanation:Radiometric dating is a method used by scientists to date geological materials such as rocks, and it provides support for the theory of evolution by natural selection in several ways.
Firstly, it gives us an understanding into the timeline of life on Earth. By accurately estimating the age of fossils, we can create a timeline for when specific organisms existed, how they evolved over time, and the order in which they appeared or disappeared. This timeline is essential for the theory of evolution.
Also, it aids in the evidence of gradual change (evolution) over long periods of time (deep time). In other words, by showing that the Earth is billions of years old, radiometric dating supports the idea that slow, progressive changes (i.e., 'natural selection') have shaped life as we know it today.
Learn more about Radiometric Dating and Evolution here:https://brainly.com/question/19045878
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During winter, tree sap can sometimes freeze and cavitation (the formation of an air pocket) may occur. Which one of the following mechanisms of sap transport would you expect to be most immediately affected by cavitation? 1. symplast function
2. pressure flow (mass flow)
3. cohesion transpiration
4. root pressure
5. active transport
Answer:
Option 3. cohesion transpiration is the correct answer.
Explanation:
Plants release water through transpiration while cohesion is responsible for moving more water throughout the xylem. When the water evaporate through the stomata, more water is pulled from roots into stem and eventually reach the leaf this process is called transpiration-cohesion theory. (More explanation in attached Picture)
Help, earth science!!!
Which of these affect Earth’s climate over a shorter period of time?
A): changes in solar output
B): changes in Earth’s tilt
C): changes in orbital shape
D): changes in ocean currents
Changes in ocean currents
Explanation:
Ocean currents are a continuous and directional flow of ocean water. This is caused by the forces that act on the water like variations in temperature, the waves breaking, salinity, the wind or even the Coriolis effect. Ocean currents travel thousands of miles, thereby establishing a conveyor belt globally which brings out the different climatic conditions across the world. The ocean acts either above the surface of the ocean or below the surface of the ocean and moves horizontally or vertically.As horizontal currents move towards south or northwards, they carry the warm or cool water over an extended distance. These ocean currents are displaced water that affects the air, by warming or chilling it, and transfers the same effect to the land surface which it blows.Skeletal muscles generate maximum tension when the maximum number of cross-bridges can form in the zone of _______.
You have been asked to participate in the cleanup of an old mining site. You build a treatment wetland to clean up a contaminated spring flowing out of the mine area. Before sending the water to the wetland, you pass it through a holding tank where Thiobacillus removes heavy metals. The plants and microbes of the wetland will absorb many of the contaminants that remain in the water. Your method is an example of _____.
a) landscape ecology
b) bioremediation
c) biodiversity maintenance
d) preservationism
Answer:
b) Bioremediation
Explanation:
The use of natural occuring or intentionally introduced micoorganisms to treat environmental pollutants is called as Bioremediation.
Most of the bioremediation processes includes oxidation-reduction reaction.The natural degradation process of pollutants is improved by bioremediation.Green plant, Decomposers and their enzymes are used in bioremediation to imrprove the condition of the environment.