Answer:
Amount of DNA in a diploid G2 nucleus after S phase has already undergone DNA replication hence the amount of DNA in a diploid nucleus in G1 would be 200 ng. As the organism is diploid, 200 ng of DNA would be carried on 14 chromosomes.
A single ascospore nucleus of Neurospora crassa should contain 200 nanograms (ng) of DNA, carried on 7 chromosomes.
Explanation:The process described in the question involves both meiosis and mitosis as part of the life cycle of the ascomycete Neurospora crassa. As it begins with a diploid G2 nucleus containing 400 ng of DNA and 14 chromosomes. During meiosis, this number is halved, resulting in four daughter cells, each with half of the original DNA (200 ng) and seven chromosomes. Further mitosis, which doesn't change the amount of DNA or number of chromosomes, doubles the number of cells, results in eight ascospores each containing 200 ng of DNA and seven chromosomes.
Learn more about Neurospora crassa reproduction here:https://brainly.com/question/29661931
#SPJ2
What word is used to describe the exact position of a gene on a chromosome?
Final answer:
The term for the exact position of a gene on a chromosome is called the locus. Each locus can be mapped and used to understand genetic inheritance, and is associated with specific alleles, which are variants of a gene at a locus.
Explanation:
The exact position of a gene on a chromosome is referred to as the locus (singular), with loci being the plural form. Each locus corresponds to a specific location where a gene is found, which can be used in genetic mapping to identify where the gene resides on a particular chromosome. During metaphase, a stage of mitosis, chromosomes align at the metaphase plate, allowing for observation of their structure, including the specific loci of genes. Chromosomes have arms called 'p' for the short arm (petite) and 'q' for the long arm, and are further subdivided by numbers to precisely specify gene locations.
Moreover, genes are associated with alleles, which are the different variants of a gene that may exist at a particular locus. The entirety of an organism's alleles composes its genotype, which in turn has the potential to affect the phenotype through the expression of these genes. The terms locus, gene, and allele are distinct but related, and understanding their meaning is crucial for studying genetics and inheritance patterns.
What mechanisms help infants survive before they have an opportunity to learn adaptive behavior?
Answer:
Reflexes
Explanation:
The complete question is :
What mechanisms help infants survive before they have an opportunity to learn adaptive behavior?
a. Dynamic systems
b. Motor skills
c. Reflexes
d. Vision and hearing
A muscle reaction that takes place automatically in response to stimulation is termed as a reflex action. The reflexes that are present in infants which helps them to survive before they display adaptive behavior are termed as infant reflexes.There are several reflexes that are displayed by the infants such as :Sucking reflex - the infant sucks when an area around the mouth is touchedStartle reflex - the infant pulls his arms and legs in after hearing a loud noiseStep reflex - the infant performs stepping motions when the sole of the foot touches a hard surfaceThere are many more such reflexes present in the infants that are absent in the adults.
Cystic fibrosis affects the lungs, the pancreas, the digestive system, and other organs, resulting in symptoms ranging from breathing difficulties to recurrent infections. Which of the following terms best describes this expression of phenotypes
a, incomplete dominance
b.codominance
c multiple alleles
d epistasis e pleiotropy
Answer:
e: pleiotropy
Explanation:
Pleiotropy is a genetic term that describes a situation in which a single gene controls the expression of multiple traits.
Depending on the underlining mechanism, there are different types of pleiotropy:
gene pleiotropy: this occur when a protein representing a gene interacts with other proteins or catalyses multiple reactionsdevelopmental pleiotropy: this occur when mutation of a gene have multiple phenotypic effectsselectional pleiotropy: This occur when the phenotypic expression of a single gene has multiple effects on fitness.In this case, cystic fibrosis gene has multiple phenotypic effects which include its effects on the lungs, pancreas, digestive system and other organs.
The correct option is e.
The correct answer to the student's question is (e) pleiotropy, as cystic fibrosis is a genetic disorder caused by a mutation in a single gene leading to symptoms in multiple organs. Pleiotropy is when one gene influences multiple phenotypic traits.
Explanation:Cystic fibrosis is a genetic disorder that affects multiple organs in the body, including the lungs, pancreas, and digestive system. The term that best describes the expression of symptoms in various organs caused by a single gene is pleiotropy. Therefore, the correct answer to the question is (e) pleiotropy.
Cystic fibrosis is caused by a mutation in a gene called CFTR and is inherited as an autosomal recessive trait. This single gene alteration leads to a wide range of phenotypic expressions, such as the production of thick and sticky mucus that obstructs respiratory and digestive organs. This results in chronic lung infections, problems with digesting food properly, and other complications.
Medical advancements have increased life expectancy for people with cystic fibrosis, which was once very low. It is a progressive condition that requires careful medical management. Knowledge of its inheritance and impact on multiple body systems is critical for understanding the disease and advancing treatment options.
If you place a probe in the aorta what chamber will it exit
Answer:Through the Left ventricle
Explanation:
.
Anatomically, the left ventricle empty directly into the aorta. Therefore the probe will pass through the aortic valve to exist in left ventricle.
The left ventricle pumps oxygenated blood out of the heart through the aorta into the systemic circulation. Consequently, there must be a closed link between the chamber which stores and empty the blood (left Ventricle), and the vessel which conveys blood to the target areas (Aorta) in the systemic circulation.
check the attachments for clearer picture of this.
.
The result of the following cross indicates the orange eyes are _____ black eyes. A cross between two aliens with black eyes. Their offspring have two phenotypes. 247 of them have black eyes, 86 of them are orange-eyed. The total number of the offspring is 333.
Answer:
The result of the following cross indicates the orange eyes are recessive to black eyes
Explanation:
According to Mendel, a cross involving two individuals that are heterozygous for a dominant trait will yield offspring in the phenotype ratio 3:1 with the dominant trait accounting for about 75% of the phenotype and the recessive trait accounting for the remaining 25%.
In this case, black eye colour phenotype is 247 while orange eye colour phenotype is 86.
Calculating the percentage for each trait
Black eye = 247/333 x 100% = 74.1%
Orange eye = 86/333 x 100% = 25.8%
74.1:25.8 is approximately 3:1
Hence, it is obvious that the orange eyes are recessive while the black eyes are dominant.
Answer:
recessive
Explanation:
did a punnet square
Single-celled Paramecium live in pond water (a hypotonic environment relative to the cytosol). They have a structural feature, a contractile vacuole, which enables them to osmoregulate. If sucrose or saline was added to the pond water in different concentrations (in millimolars, mM), under which conditions would you expect the contractile vacuole to be most active?
Answer:
The contractile vacuole will be most active when the concentration of sugar will be 0.0 mM sucrose.
Explanation:
A hypotonic solution can be described as a solution in which the concentration of the solutes is more inside the cell. So the addition of sucrose or saline will not effect such kind of cell.
But if such kind of cell is transferred into an isotonic solution where there is 0.0mM of sucrose, then the solutes will move out of the cell. The vacuole will become more active to take in solutes from the solution in such kind of condition.
A Paramecium's contractile vacuole, which helps regulate the water content within the cell, would be most active in a hypotonic environment (low saline or sucrose concentration) as the water continuously enters the Paramecium and needs to be continually expelled.
Explanation:A single-celled organism such as a Paramecium uses its contractile vacuole to regulate the amount of water inside it, a process called osmoregulation. In a hypotonic environment like pond water where there's a lower concentration of solutes outside the cell, water rushes into the paramecium due to osmosis. This can potentially lead to cell bursting or cytolysis.
If the pond water (hypotonic to the Paramecium cytosol) has sucrose or saline added, which would increase the solute concentration, it becomes isotonic or hypertonic. Here, water would either stay balanced or leave the paramecium, respectively. In these situations, the contractile vacuole would pump out less water because water isn't entering the cell as much as before.
So, the contractile vacuole is most active in a hypotonic environment, i.e., low sucrose or saline concentration where water continuously enters the paramecium and needs to be continually expelled.
Learn more about Osmoregulation here:https://brainly.com/question/31605052
#SPJ6
Linda is conducting a research study on osteoporosis, and she wants her study to create awareness among those most affected by the disease. In this scenario, her target group would most likely be:
Answer: Case control analysis
Explanation:
There should be 3 target groups, 1 of them is optional.
1) Patients of osteoporosis undergoing medical and physical therapy
2) Patients of osteoporosis not undergoing medical and physical therapy
3) Control group
Ecologic studies_________________.
a. are expensive and require a great deal of time to conductb. are a good approach for generating hypotheses
c. provide accurate measurements of exposure
d. yield results that can be applied directly to individuals
Answer:
b. are a good approach for generating hypothesesb. are a good approach for generating hypotheses
The protostome developmental sequence arose just once in evolutionary history. True or False
Answer:
The answer is true.
Explanation:
The protostome developmental sequence arose just once in evolutionary history. Resulting in two main subgroups, lophotrochozoa and Ecdysozoa.
Suggesting that the division of these two groups occurred after the protostome developmental sequence appeared.
Which of the following is an animal with rigid bones, jaws, and a swim bladder? Please choose the correct answer from the following choices, and then select the submit answer button. sharks lobe-finned fish salmon lampreys hagfish
Answer:
Salmon has the rigid bones, jaws, and a swim bladder.
Explanation:
The bony fishes have the skeleton made up of bones, same as in case of salmon. It helps them in support, move and give protection to various body parts. The swim bladder of salmon is filled with gas that helps to create the thrust and contributes in maintain the control over buoyancy. The extensible jaw present in salmon helps them in swimming in the deep water easily.What accounts for the uniform diameter of the DNA molecule? A.The two sides of the DNA molecule are held together by hydrogen bonds.
B.A purine always bonds with a pyrimidine.
C. One side of the DNA molecule has an unconnected 5' phosphate group and the opposite end has an unconnected 3' hydroxyl group.
D. The 3' carbon of one deoxyribose and the 5' carbon of another deoxyribose bond together.
E.The alternating sugar and phosphate backbone coils around the outside of the helix.
Answer:
B. A purine always bonds with a pyrimidine.
Explanation:
DNA is a polymer of deoxyribonucleotides each of which has a nitrogenous base, a pentose sugar and phosphate group. There are two types of nitrogenous bases present in DNA. Adenine and guanine are the purine bases and have two rings in their structure while the cytosine and thymine are the pyrimidine bases with a single ring structure.
A purine base of one DNA strand always pairs with the pyrimidine base of another DNA strand. Adenine (purine) makes two hydrogen bonds with thymine (pyrimidine) while guanine (purine) makes three hydrogen bonds with cytosine (pyrimidine). The pairing of a purine with a pyrimidine base keeps the diameter of a DNA double helix uniform throughout the length. For instance, the diameter of B-DNA is around 20 angstrom.
You recently identified a molecule that you believe is a primary messenger for a signal transduction mechanism. All you know about this ligand is that it is hydrophilic. Where would you expect to find initial interaction of the molecule with its receptor?
-in endosome vesicles-on the outer surface of the plasma membrane-within the cytoplasm of the cell-on the cytoplasmic side of the plasma membrane-within the nucleus of the cell
Answer: within the cytoplasm of the cell
Explanation:
There are four main types of receptors, these are:
G-protein linked Receptors
Enzyme-Linked Receptors
Nuclear Receptors
Ligand-Gated Ion Receptors
Out of these four types; It has become apparent that ligand-gated ion channels (ionotropic receptors) in the neuronal plasma membrane interact via their cytoplasmic domains (i.e within the cytoplasm of the cell) with a multitude of intracellular proteins. Another fact is that, Intracellular receptors are located in the cytoplasm of the cell. Also, Ligand-Gated Ion Receptors is the only Hydrophilic Ligand.
Unlike the G-protein linked Receptors (transmembrane protein (TP)). A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the cell membrane. They frequently undergo significant conformational changes to move a substance through the membrane. They usually highly hydrophobic and aggregate and precipitate in water.
Enzyme-Linked Receptors are transmembrane proteins as well, with their ligand-binding domains on the outer surface of the plasma membrane. They are also hydrophobic in nature.
Nuclear Receptors are nuclear hormone receptors that directly binds within the nucleus of the cell to regulate the expression of targeted genes.
In Mediterranean climate regions like portions of California, a wetter than normal winter often leads to greater severity of fires the following summer. This seeming paradox occurs because increased rain leads to_____________.
A. a greater accumulation of chapparal biomass
B. higher pollination rates of annual flowers
C. greater recreational use of parklands
D. greater erosion and damage of access roads
E. decreased summer rainfall
Answer:
The correct answer is A. a greater accumulation of chapparal biomass.
Explanation:
The increase of rain leads to a greater accumulation of chapparal biomass, and then, when the winter is over, there's a big amount of dry biomass that can start fires.
After mixing A heat-killed, phosphorescent (light-emitting) strain of bacteria is mixed with a living, non-phosphorescent strain. Further observations of the mixture show that some of the living cells are now phosphorescent. Which of the following observations would provide the best evidence that the ability to phosphoresce is a heritable trait?
Answer:
Phosphorescence in descendants of the living cells.
Explanation:
The DNA acts as the heritable molecule that pass down from the parents to their offsprings and move from one generation to the next generation. Different experiments had been done to identify the heritable molecules.
In an experiment, non fluorescent become fluorescent when mixed with the dead fluorescet cells. This means the material has been transformed to the non fluorescent cells. The phosphorescent acts as the descendants in the living cells and may be inherited to the future generations as well.
In the polymerization of DNA, a phosphodiester bond is formed between a phosphate group of the nucleotide being added and which of the following atoms or molecules of the last nucleotide in the polymer?
Answer:
3' OH ( hydroxyl group).
Explanation:
DNA is present as the genetic material in almost all the living organisms except in case of some viruses only. DNA is made of the polymers of the nucleotides.
The phosphodiester bond is present between the two nucleotide chains. The phosphodiester is a covalent bond formed in which the phosphate group of nucleotide is involved with the hydroxyl group of the sugar and a small molecule like water is removed during the process.
Thus, the correct answer is 3' OH ( hydroxyl group).
What structural modification of the small intestine slows the movement of chyme through the lumen? a) intestinal crypts b) villi c) microvilli d) circular folds.
Answer:
The correct answer is d) circular folds.
Explanation:
Circular folds slow food going through the small intestine so the villi and microvilli can help the food to be processed and digested properly. Also, the presence of these circular folds increases the surface where the nutrients are being absorbed.
The circular folds (d) of the small intestine are structural modifications that slow the movement of chyme, allowing for more time for digestion and nutrient absorption.
Explanation:The structural modification of the small intestine that slows the movement of chyme through the lumen is d) circular folds. These folds, also known as plicae circulares, are large, valvular flaps projecting into the lumen of the small intestine. Their primary function is to slow down the passage of food to allow for adequate time for digestion and absorption.
The villi and microvilli, on the other hand, are primarily responsible for increasing the surface area for nutrient absorption. Villi are small, finger-like projections that extend into the lumen of the small intestine, and microvilli are even smaller projections on the apical surface of epithelial cells of the villi, forming a brush border. While villi and microvilli are essential for nutrient absorption, they do not specifically function to slow the movement of chyme like the circular folds do.
The lumen is the inside of the small intestine where digestion and absorption take place. While all these structures – circular folds, villi, and microvilli – work together to optimize the efficiency of digestion and absorption, it is the circular folds that chiefly impede the flow chyme, providing more time for nutrients to be absorbed as it passes through the small intestine.
Which part of the CNS sorts almost all sensory information ascending to the cerebral cortex? Which part of the CNS sorts almost all sensory information ascending to the cerebral cortex? thalamus hypothalamus pons mesencephalon
Answer:
The correct answer will be option-Thalamus
Explanation:
Thalamus is the small structural and functional part of the brain which lies between the cerebral cortex and the midbrain.
The thalamus is known as the relay system of the brain as it collects all the sensory information from the afferent impulses, analyses it and then send it to the appropriate cortical areas.
Since thalamus collects and relays the sensory information from the CNS to the cortical areas therefore, the thalamus is the correct answer.
Which term best describes the interval between the birth of the newborn and the return of the reproductive organs to their normal nonpregnant state?
A. Involutionary period because of what happens to the uterus
B. Puerperium, or fourth trimester of pregnancy
C. Mini-tri period because it lasts only 3 to 6 weeks
D. Lochia period because of the nature of the vaginal discharge
Answer:
B. Puerperium, or fourth trimester of pregnancy
Explanation:
Puerperium or the fourth trimester of pregnancy is also known as the postpartum period. This period starts immediately after the mother gives birth to a child. During this period the size of the uterus and other reproductive organs along with the hormone levels return to their normal state.It is the phase where regression of all the anatomical and physiological changes that took place i in the reproductive organs of the females takes place.This phase is divided int three periods -1. Immediate puerperium, or the first 24 hours after parturition
2. Early puerperium, which extends until the first week postpartum;
3. Remote puerperium, which includes the period required for involution of the genital organs and return of menses, usually approximately 6 weeks.
This phase is highly critical for the mother as this requires rest and proper care as there are risks of bleeding. Therefore, the midwife or the nurse must take proper care of the mother.Taxol is an anti-cancer drug that prevents uncontrolled cell proliferation by stabilizing microtubules, which causes arrest of the cell cycle. If dividing cells are treated with Taxol, at what stage of the cell cycle would you predict the arrest would occur?a. prophase
b. telophase
c. anaphase
d. metaphase
e. G1 of interphase
Answer:
C. Anaphase
Explanation:
Taxol's primary action is to bind to microtubules, especially β-tubulin, and prevent their depolymerization, thereby stabilizing mitotic spindle during anaphase of mitosis which leads to arrest of cell cycle.
Option d.
Taxol, an anti-cancer drug, disrupts cell division by stabilizing microtubules and thus preventing chromosome alignment. This results in a cell cycle arrest predicted to occur in metaphase when cells are treated with the drug.
Explanation:The anti-cancer drug Taxol prevents uncontrolled cell proliferation by stabilizing microtubules. This stability prevents the chromosomes from aligning properly in the middle of the cell. Given this mechanism of action, when dividing cells are treated with Taxol, it is predicted that the arrest would occur in metaphase (choice d). Metaphase is the specific phase of the cell cycle in which the chromosomes align in the middle of the cell, a process facilitated by the normal functioning of microtubules. When this process is disrupted by Taxol, the cell cannot proceed to the next stage of the cell cycle, causing an arrest in cell division.
Learn more about Taxol here:https://brainly.com/question/36351732
#SPJ11
DNA replication:
A) Requires the cooperation of over a dozen enzymes and other proteins.
B) Requires DNA polymerase and RNA polymerase.
C) Is a very fast process that results in numerous errors.
D) Is a slow process that results in virtually no errors.
Answer:
The answer is A) Requires the cooperation of over a dozen enzymes and other proteins.
Explanation:
DNA replication is a very complex process that involves many enzymes such as the helicase, which breaks the hydrogen bonds between the two DNA strands, the SSBs that avoid the strands from coming back together, and that only for the beginning of the process. But there are many more enzymes and molecules helping the replication.
Uncle Smiley is heterozygus for a yellow face, married a woman with a green face.Both of them always wanted a large family! If they were to have 12 children, what are the probability that the children would have yellow faces? How many would have green faces? Create a Punnett square to help you find your answer
The probability that the children would have yellow faces is ½. Six children would have green faces.
Explanation:
It is given here that uncle smiley is heterozygous for yellow face. If an individual is heterozygous for a trait then it will be the dominant trait that will be expresses. Thus the dominant trait here is yellow face.
The wife has green face which means that she is homozygous recessive since she expresses the recessive trait. Let the letter Y represent the dominant yellow and letter y represent the recessive trait green. The trait can be represented as
[tex]Yy \times yy[/tex]
Yy Yy yy yy
Yellow yellow green green
It is clear from the cross that half of the individuals will have yellow face and half will have green face. Thus if the couple has 12 children the probability that the children have yellow faces will be 1/2.
6 children would have green faces.
When a heterozygous yellow-faced person (Yy) has children with a green-faced person (yy), there's a 50% chance for each child to have a yellow face (Yy) or green face (yy), with an expected ratio of 6 yellow to 6 green faces among 12 offspring.
Explanation:Uncle Smiley, who is heterozygous for a yellow face, when crossed with a woman with a green face, produces offspring with either yellow or green faces based on Mendelian genetics. A heterozygous yellow face can be represented as Yy where Y represents the dominant yellow allele and y represents the recessive green allele. If Uncle Smiley's genotype for face color is Yy and his wife's genotype is yy, each child's face color is determined by one allele from each parent.
Using a Punnett square, we can predict the outcomes for their children. The square would show that there is a 50 percent chance for a child to have a yellow face (Yy) and a 50 percent chance for a child to have a green face (yy). Therefore, for 12 children, we would expect about 6 with yellow faces and 6 with green faces, though actual results may vary due to random assortment of alleles.
A researcher has crossed two dihybrid fish with the genotype d+/d ; t+/t. He notices that the progeny of this cross demonstrate a phenotypic ratio of 9:7. What type of gene interaction do these results suggest?
A. dominant epistasis
B. suppression
C. recessive epistasis
D. The two genes do not interact in any way.
E. The two genes act in the same pathway.
Answer:
The correct answer is C: recessive epistasis. Double recessive epistasis.
Explanation:
Gene interactions happen between genes at different levels and have implications in the phenotypic expression, causing a wide genetic variability.
Epistasis means "interruption" and refers to interactions between genes located in different loci in the same chromosome. An “epistatic gene” can alter, influence, or suppress the expression of a "hypostatic gene". When the epistatic gene is recessive, the interaction is known as "recessive epistasis".
Observing the altered phenotype proportions of the offspring can reveal which interaction is operating in the trait determination.
In simple recessive epistasis, the proportion is 9:3:4. But in "double recessive epistasis", the phenotypic proportion is 9:7. In this case, both recessive alleles in any of both loci, are capable of suppressing the phenotype. Those individuals that present two recessive alleles for any loci have the same phenotype. These are dd / T --, D --/tt, dd/tt.
DT Dt dT dt
DT DDTT DDTt DdTT DdTt
Dt DDTt DDtt DdTt Ddtt
dT DdTT DdTT ddTT ddTt
dt DdTt Ddtt ddTt ddtt
Phenotypic proportion: 9/16 (D-T-)
7/16 (D-tt, ddT-, ddtt)
Months after last taking a drug, a former drug abuser still produces very little serotonin. The person is depressed and anxious and has great difficulty remembering new material. MOST likely, the abused substance was:A) Ecstasy.
B) cannabis.
C) LSD.
D) benzodiazepine.
Answer: Ecstasy
Explanation:
It is called as Molly and is a very know psychoactive drug which is used as as a recreational drug.
The effect includes altered sensations, empathy, pleasure and increased energy.
It is taken orally and it shows its effect in 30 to 40 minutes after the drug is taken and lasts for 3 to 6 hours. The longer effects of this drug results in decreased level of serotonin and the person stays in depression for a longer period of time.
The person might have taken ecstasy.
Why are telomeres a necessary component of linear chromosomes?
Answer:
Bacause they protect the chromosomes
Explanation:
A telomere is a repetitive region located at the ends of a chromosome, their function is to act as caps to protect the inner regions when the chromosome is worn down during DNA replication. This worning out happens because a short stretch of DNA is not covered by an Okazaki fragment and therefore is not copied, eventually over multiple rounds of division the telomers will prevent the shortening to reach the important inner part that contains the genetical information.
I hope you find this information useful and interesting! Good luck!
Telomeres play a vital role in the protection of genes present in chromosomes during cell division. They prevent the deletion of genes at the ends of chromosomes. The enzyme telomerase facilitates this process, elongating the lagging strand template so DNA polymerase can replicate chromosome ends.
Explanation:Telomeres are a crucial part of linear chromosomes, serving a protective function to stop the deletion of genes during cell division. The ends of the chromosomes, known as telomeres, consist of noncoding repetitive sequences. In humans, a sequence -TTAGGG- repeats between 100 and 1000 times within these telomeres.
The enzyme telomerase plays a significant role in the maintenance of chromosome ends. This enzyme, which was discovery led to a Nobel Prize in 2009 for Elizabeth Blackburn, Carol W. Greider, and Jack W. Szostak, contains a catalytic part and an inbuilt RNA template. It attaches itself to a chromosome's end, then adds complementary bases to the RNA template on the DNA strand's 3' end.
Once the 3' end of the lagging strand template is extended enough, DNA polymerase can add nucleotides that match the chromosome ends, enabling the replication of chromosome ends. Therefore, the role of telomeres is crucial in preserving our genes and preventing potential chromosomal degradation over time due to cell division.
Learn more about Telomeres here:https://brainly.com/question/33791614
#SPJ12
Unlike green algae which can only live in water, a waxy covering over the epithelial cells of plants, called the ________ help(s) them retain water and gave them the adaptation needed for terrestrial life.
Answer:
Cuticle
Explanation:
Plant cuticle is a waxy covering over the aerial epidermal cells of all the plants. Waxes are composed of cutin and a various organic solvent-soluble lipids. The cuticle is an extracellular hydrophobic layer which provides protection against desiccation and external environmental stresses. In other words the cucticle helps to retain water and give plants an adavanthe to live terrestrial life.
What is LUCA and how long ago did LUCA exist? What is the general interpretation of the observation that members of a single gene family are found in all three domains of life?
LUCA the last universal common ancestor; it is exist in 3.5 billon years ago in the paleoarchean era, a few hundred million years after the earlier fossils evidence of life.
Explanation:
It is the single celled bacteria like organisms living in volcanic era. The three domain of the life are Archaea, bacteria, Eukaryotas. The observation that member of the single gene family are found in the all three domain of life.
It is suggested that the progenitor gene that give rise to the family member existed in the LUCA , before the time that the three domain diverged.
Final answer:
LUCA is the hypothetical early cell or group of cells that gave rise to all subsequent life on Earth. It existed around 3.5 billion years ago and was a prokaryotic cell. The presence of a single gene family in all three domains of life suggests a common ancestry.
Explanation:
Last Universal Common Ancestor (LUCA) is the hypothetical early cell or group of cells that gave rise to all subsequent life on Earth. It is estimated to have existed around 3.5 billion years ago and would have been a prokaryotic cell without a nucleus or membrane-bound organelles. The observation that members of a single gene family are found in all three domains of life (Bacteria, Archaea, and Eukarya) suggests a common ancestry and indicates that these genes were present in LUCA. This supports the idea of a universal common ancestor for all life on Earth.
The structure that is in physical contact with the auditory receptor stereocilia is the
Answer:
The structure that is in physical contact with the auditory receptor stereocilia is the tectorial membrane.
Explanation:
The tectorial membrane is a structure or a thin layer of tissue that is floating in the endolymph on the stereocilia of the ciliated cells. Ciliated cells, which are sensory cells attached to the surface of the basilar membrane.
When the ciliated cells move up and down, microscopic projections similar to sows (known as stereocilia), which are located above the ciliated cells, cause the cilia to lean towards the side wall of the cochlea. This inclination makes that some channels that look like pores open, which are at the tips of the stereocilia. When this happens, certain chemicals enter the cells, thus generating an electrical signal. The inner ciliated cell is activated, probably by a direct contact of its stereocilia with the Hensen band of the tectorial membrane, the synapse between the ciliated cell and the auditory nerve fibers, send a message to the brain, which converts it into sounds that we can recognize and understand.
A 5.0-g egg falls from a 90-cm-high counter onto the floor and breaks. What impulse is exerted by the floor on the egg?
Answer:
0.021 kgm/s
Explanation:
using energy
change potential energy of the egg = change in kinetic energy of the egg
mgh = 1/2 mv² m in kg, h in meters
5.0g = 5.0/1000 kg= 0.005 kg
90 cm = 90 / 100 = 0.9 m
cancel m on both side
gh = 1/2 v²
make v subject of the formula
v = √2gh = √2×9.81×0.9 = √17.658 = 4.2 m/s that is the velocity of the egg on impact with floor and the initial velocity of the egg is zero.
impulse = m × Δv = 0.005 × 4.2 = 0.021 kgm/s
The impulse exerted by the floor can be calculated by finding the change in momentum of the egg, using the formula Impulse = Mass * (Final velocity - Initial velocity). To find the final velocity, we use the equations of motion and take into account the height of the fall and the acceleration due to gravity.
Explanation:To calculate the impulse exerted by the floor on the egg, we can use the formula Impulse = Change in Momentum. In this physics problem, we are given the initial velocity of the egg (0 m/s), its mass (5.0 g), and the height from which it falls (90 cm). To calculate the final velocity after hitting the floor, we need to use the equations of motion. The equation for final velocity given initial velocity, acceleration, and distance is: v² = u² + 2as. Here, u = initial velocity = 0 m/s, a = acceleration due to gravity = 9.8 m/s², and s = distance (height) = 90 cm = 0.9 m. Solving the equation gives us the final velocity. Once the final velocity is obtained, it can be substituted back into the impulse formula: Impulse = Mass * (Final velocity - Initial velocity). Please note that since the direction of the force of the floor on the egg is opposite to the direction of fall, the impulse would have a negative sign.
Learn more about Impulse here:https://brainly.com/question/30466819
#SPJ11
A researcher is comparing the species diversity of two islands. Both islands are roughly equal in size. However, one island is much closer to the mainland. She determines that the S value for the island closer to the mainland is _____ the S value for the island located farther from the mainland. In addition, she finds that the closer island's extinction rate is _____ the extinction rate on the farther island.
Answer:
The S value for the island closer to the mainland is higher/bigger than the S value for the island located farther from the mainland.The closer island's extinction rate is equal to the extinction rate on the farther island.Explanation:
Island biogeography theory establishes that the two factors that affect species richness in natural communities on an island are the distance from the mainland and the size of the island.
At the same time, these factors affect inmigration and extinction rates.
According to the theory, islands that are closer to the continent have higher possibilities of receiving immigrants than those islands that are located farther from the mainland. This is the effect of distance.
The effect of size is reflected in the relation between island size and species diversity. In smaller islands, the probability of extinction is higher than in bigger islands. Bigger islands can have more species than smaller ones.
In the case of two islands of the same size and different distance to the mainland, both of them will have the same extinction rate, but the one closer to the continent will have a higher immigration rate, and so, a higher amount of species. The S value will be higher on the island closer to the continent.
While traveling through the rain forests of Peru, you are introduced to a rare and exotic plant. You discover that it contains a toxin that blocks the reabsorption of sodium ions from the proximal tubule. If administered, what affect would this toxin have on the reabsorption of water and other electrolytes? While traveling through the rain forests of Peru, you are introduced to a rare and exotic plant. You discover that it contains a toxin that blocks the reabsorption of sodium ions from the proximal tubule. If administered, what affect would this toxin have on the reabsorption of water and other electrolytes? The toxin would significantly decrease the amount of water reabsorbed but would significantly increase the number of other electrolytes reabsorbed by the proximal tubule. The toxin would significantly increase the amount of water absorbed and the electrical gradient for reabsorbing chloride. The toxin would significantly decrease the amount of water and certain electrolytes reabsorbed by the proximal tubule. The toxin would significantly increase the amount of water and calcium ions reabsorbed by the proximal tubule.
Answer:
A. Oedema and ion imbalance
Explanation:
The proximal tubule is very important to the maintenance of homeostasis in the renal microenvironment. The alterations of the physiological functions will therefore distort the reabsorption of other ions. The blockage of sodium reabsorption into the channel will leads to an hypotonic internal environment. This will afterward leads to reduction of the reabsorption of water into the organ and increase the reabsorption of other ions into it. This will have clinical effect on the organism. Which is oedema of the extracellular surrounding of the tubules through accumulation of fluids and could lead to imbalance in neurological sense due to the imbalance in other ions.