Answer:
Modified apocrine sweat glands
Explanation:
The ceruminous glands are similar to sebaceous glands, belonging to the group of sweat glands. These glands secrete a sticky material, the ear wax, that protects the thin skin lining the ear canal.
As soon as a dust, dirt or an insect enters the ear canal at the beginning of the ear wax, the wax retains, wraps and pushes it outside the ear canal.
This secretion is lubricating as well as acidic, which helps to kill potentially harmful bacteria and fungi in the ears.
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.A recessive allele on the x chromosome is responsible for red-green color blindness in humans. Alleles are C = normal and c = color blind. A woman with normal vision whose father is color blind marries a color-blind male. What is the probability that this couple's first son will be color-blind? A) 1/4 B) 1/2 C) 2/3 D) 3/4
Answer:
1/2
Explanation:
The allele for the red-green color blindness is X-linked recessive. The father of the woman was colorblind (X^cY) which means that the woman is a carrier for the allele and has genotype (X^cX). The genotype of the colorblind male would be X^cY. A cross between a carrier woman and a color-blind man would produce progeny in following ratio= 1/2 colorblind daughter: 1/2 normal daughter: 1/2 colorblind son: 1/2 normal son.
Therefore, there is a 50% probability that their first son is colorblind.
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
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.
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.
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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.
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.
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.
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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.
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What factor is being used to measure the rate of photosynthesis? What does this factor have to do with what is happening in the plant cells?
Explanation:
with greater TEMPERATURES, LIGHT INTENSITY, AND CO2. photosynthesis in the plant cells increase, therefore causing the plant to grow larger and stronger to survive winter or dormant months.
Final answer:
The rate of photosynthesis is measured by factors such as light, water, and carbon dioxide availability. Light powers the photosynthesis process within the chloroplasts, carbon is fixed into sugars, and water and nutrients are absorbed through roots. These factors are critical for the plant to produce energy through photosynthesis and sustain its metabolism via respiration.
Explanation:
Measuring the Rate of Photosynthesis
The rate of photosynthesis in plants can be measured by several factors, one of which is the amount of light a plant receives. Light is crucial in powering the photosynthetic process and as such, up to a certain point, an increase in light intensity results in an increased rate of photosynthesis. Light energy is used by chlorophyll within the chloroplasts to convert carbon dioxide (CO₂) from the air and water (H₂O) from the soil into glucose, a sugar used as an energy source, and oxygen (O₂).
The chloroplast is the main cellular structure involved in photosynthesis, occupying a considerable space within plant cells. Within the chloroplasts, carbon is fixed during the Calvin cycle, where CO₂ is transformed into organic compounds, essentially 'storing' it within the plant. This process is central to the generation of food not only for the plant itself but also for organisms that consume plants.
Factors such as water, carbon dioxide, and nutrients in the soil, as mentioned by the video from Britannica, are also vital for photosynthesis. Without adequate water, absorbed through the roots, or sufficient CO₂, which enters the leaves through the stomata, photosynthesis rates are significantly hindered.
Understanding the relation between photosynthesis and cellular respiration is also important. While photosynthesis stores energy by producing glucose, respiration is the process where plants utilize this stored energy to maintain metabolism. In the absence of light, plants will continue to respire but will not photosynthesize, which can eventually lead to a decrease in their mass.
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).
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.
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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.
You cross two fruit trees. one tree produces lemons with spiky leaves and bumpy fruit. the other produces lemons with smooth leaves and smooth fruit. your f1 generation produces lemons with smooth leaves and spiky leaves and bumpy fruit. what are the genotypes of the parents?
A. l = lemons with bumpy fruit;
B. l = lemons with smooth fruit;
C. s = smooth leaf;
D. s = spiky leaf.
Answer:
Explanation:A
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.
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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.
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.
Green algae differ from land plants in that many green algaeA) are heterotrophs.B) have alternation of generations.C) have cell walls containing cellulose.D) have plastids.E) are unicellular
Answer:
The correct answer is E) are unicellular
Explanation:
Most of the green algae are unicellular and most of them have two flagella for locomotion. The most common habitat of green algae in freshwater but they are also found on moist soil and marine environment.
Some species of green algae form colonies and huge filaments but mostly remain single-celled in their life. They show some similarities with higher plants as they have chlorophyll a and b like higher plants which they use to do photosynthesis and their chloroplast is double membraned like plants.
Some examples of green algae are chlorella, Chlamydomonas, volvox, spirogyra, etc. So green algae differ from land plants as they are mostly single cellular.
Green algae differ from land plants in that they are unicellular, lack true tissues and organs, and do not have a waxy cuticle to prevent desiccation.
Explanation:Due to the fact that they share the same photosynthetic pigments as plants, green algae are closely related to plants. In that, they can produce their own sustenance using nutrients and sunshine through the process of photosynthesis, green algae and plants are closely linked. They are closely related to land plants since they have the same carotenoids and chlorophylls a and b. Green algae differ from land plants in that many green algae:
They are unicellular do not have true tissues or organs like plants do not have a waxy cuticle to prevent desiccation.Learn more about Green algae here:https://brainly.com/question/14843486
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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.
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.
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.
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.
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.
In 2000, when then-President Clinton along with Francis Collins of the Human Genome Project and Craig Venter of Celera announced the completion of a "draft" of the human genome, the event did not, in fact, represent true completion because most of what types of sequences were not included?
The millions of sequences were not put up together from their end and had no repeating non-coding sequences.
Explanation:
Celera Venter of Gene Myers started working in collaboration with the Human Genome project which was designed as a revolutionary concept of sequencing of human genome at a large scale. Myers break through the traditional method of sequencing and proposed of an idea of sequencing in a unique way.
He suggested the method of breaking genome copies and then sequencing them together using LINEs. However, the declaration of this proposal by the Human project had certain failures at first as it lacked the non-coding repeating sequence.
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.
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.
Chief cells secrete inactive pepsinogen in order to prevent acid erosion inside of the chief cells. Chief cells secrete inactive pepsinogen in order to prevent acid erosion inside of the chief cells.
a. True.
b. False
Answer:
The correct answer will be- False
Explanation:
In humans three types of chief cells are found, one of which is present in the stomach and thus are called gastric chief cells.
The gastric chief cells are involved in the digestion of proteins present in the food by producing pepsinogen enzymes in its inactive form which gets activated in the presence of acid produced by the parietal cells.
Since the pepsinogen is produced to digest the proteins and not to prevent the erosion caused by the acid inside the chief cells therefore, false is the correct answer.
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.
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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.
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.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)