Answer:
True
Explanation:
The lymphatic network begins with microscopic tubes known as:
Answer:
Lymphatic Capillaries
Explanation:
Mark brainliest if correct
Answer: Lymphatic capillaries
Which statements about the modification of chromatin structure in eukaryotes are true?
1.DNA is not transcribed when chromatin is packaged tightly in a condensed form
2.Some forms of chromatin modification can be passed on to future generations of cells
3.Acetylation of histone tails in chromatin allows access to DNA for transcription
4.Acetylation of histone tails is a reversible process.
5. Methylation of histone tails in chromatin can promote condensation of the chromatin
6. Deacetylation of histone tails in chromatin loosens the association between nucleosomes and DNA
Answer:
All of the statements are correct except 6. (Deacetylation of histone tails in chromatin loosens the association between nucleosomes and DNA)
Explanation:
Chromatin structure and its modifications can change the package of the DNA and consequently, alter the gene expression. The most common modifications of the chromatin are covalent modifications such as acetylation/deacetylation (by acetyltransferases and eacetylases), methylation (by methyltransferases), and phosphorylation (by kinases). This is the way of gene expression regulation.
The effects of modifications are different, for example methylation promotes condensation of the chromatin and as a consequence, prevents binding of transcription factors to the DNA (transcription is repressed).
Acetylation loosens the association between nucleosomes and DNA (because it neutralizes the positive charge of histones) and consequently promotes transcription. Deacetylation is a process opposite to acetylation.
True statements about the modification of chromatin structure in eukaryotes include the inhibition of transcription when chromatin is condensed, the possibility of inheriting some chromatin modifications by future generations, and that acetylation of histone tails allows transcription while being reversible. In contrast, methylation can promote condensation, and deacetylation actually increases, not decreases, DNA-histone binding.
The modification of chromatin structure in eukaryotes involves several processes that affect gene expression. The statements that are true are:
DNA is not transcribed when chromatin is packaged tightly in a condensed form.Some forms of chromatin modification can be passed on to future generations of cells.Acetylation of histone tails in chromatin allows access to DNA for transcription.Acetylation of histone tails is a reversible process.Methylation of histone tails in chromatin can promote condensation of the chromatin.Deacetylation of histone tails in chromatin does not loosen the association between nucleosomes and DNA; rather, it promotes condensation, thereby making it harder for the DNA to be transcribed due to lessened accessibility to transcription machinery.When DNA is tightly wrapped around histones in a condensed chromatin state, transcription factors and RNA polymerase cannot access the DNA, hence, transcription is inhibited. Chemical modifications, like acetylation and methylation of histone tails, determine the packing level of chromatin and influence gene expression. These processes are part of a broader regulatory system known as the histone code, which can be inherited through cell divisions and potentially across generations, contributing to epigenetic inheritance.
Who used a compound microscope to see chambers within cork and named them “cells”?
Answer:
Robert Hooke
Explanation:
Robert Hooke was a scientist in the field of biology, chemistry, physics. His great discoveries were very important, especially for the understanding of microscopic world, even though they weren't accepted at first. He was the first who developed compound microscope, in which scientists no loner had to move the specimen in order to focus it. Hooke also improved the microscope lightening. When he looked at the bark of a cork tree, he saw new structures and called it cells (because it look to him like rooms in monastery).
Robert Hooke used a compound microscope to observe chambers within cork and named them 'cells'. This observation served as a groundwork for the development of cell theory.
The scientist who used a compound microscope to observe chambers within cork and named them 'cells' was Robert Hooke. This event occurred in 1665 and is a pivotal event in the history of biology. Hooke's observation that cork was made up of tiny, individual compartments led to the development of cell theory, the idea that all living things are composed of cells.
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In a _______ stain, the dye stains the background, forming a silhouette around the unstained organism.
Answer:
In a negative stain, the dye stains the background, forming a silhouette around the unstained organism.
Explanation:
In this kind of staining, heat fixation is not a requirement since there is less distortion or shrinkage of cells.
This staining is used to accentuate the capsule surrounding bacteria and yeasts.
In negative staining, nigrosin and india ink are used in the process.
Which statements describe film badges? check all that apply. an amplifying device that indicates the presence of ionizing particles a device that permits determination of the concentration of radioisotopes in the body or other substance film sensitive to radiation that is removed and developed to measure exposure a device used for monitoring individual cumulative exposure to ionizing radiation?
Answer:
film sensitive to radiation that is removed and developed to measure exposure.
a device used for monitoring individual cumulative exposure to ionizing radiation.
Explanation:
Film badges are monitoring devices that contain photographic film which measures and record the wearer’s exposure to different ionizing radiation such as X-rays, gamma rays and beta particles. The photographic film within film badges is very sensitive, functions as a detector, and is enclosed in a vapor and light resistance cover which disallows chemical vapors, light or moisture to have an effect on the film. Film badges give a lasting radiation record and it can also differentiate between different energies of photons.
Answer:
Explanation:
just took it :)
which process occurs repeatedly after zygote formation to increase the number of cells
Answer:
Mitosis
Explanation:
A zygote is formed after the fertilization of the egg by sperm. The zygote then undergoes rapid cell division by mitosis to form a morula, blastula, gastrula and then an embryo. In mitosis, the cell replicates its genetic material and organelles and then splits into two identical cells. Mitosis is required for growth and development.
The net result of a single glycolysis run is the formation of
Answer is 2 NADH and 2 ATP
People trying to gain weight should eat most of their kilocalories from fat. select one:
a. True
b. False
I think the answer is true
Biology students at Science High spent the day swabbing surfaces throughout the school. They ran the swabs over a culture plate and then incubated the plates. 48 hours later, Carol and Jose checked their plate. "Please, do not open the cover of your culture plate!" warned their teacher. Why did the teacher give this warning? A) The life form was unknown to the teacher and she did not want to expose the students to any dangers. B) Spores from this potentially dangerous fungus would spread through the air and be inhaled by students. C) Carol and Jose's plate contains a streptococcus bacteria that could be potentially dangerous to humans. D) The culture revealed a potentially dangerous virus and if the culture plate was opened, the virus would spread rapidly.
ANSWER; C carol and Jose's plate contains streptococcus bacteria that could be potential dangerous for humans.
The teacher cautioned the students not to open the cover of the culture plate to mitigate potential health risks considering the possibility of harmful microorganisms like bacteria, fungi, or virus present, which could spread and pose risk of infection.
Explanation:The teacher warned the students not to open the cover of their culture plate due to potential health risks. When incubating samples collected from different surfaces, it's uncertain what types of microorganisms might be growing, including potentially dangerous bacteria, fungi, or virus. These can become airborne if the dish is opened, posing a risk of inhalation and infection. The exact reason isn't specified from the given options, but the general concern is clearly about preventing potential exposure to harmful agents.
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Large populations of tortoises inhabited the Galapagos Islands before humans. When humans settled on the islands and introduced goats, the number of tortoises declined. What is most likely the explanation for the decrease in the tortoise population?
Answer:it reached carrying capacity. the environment couldn't hold both the goat and tortises
Explanation:
A client with diverticular disease is receiving psyllium hydrophilic mucilloid. the drug has been effective when the client:
Answer:
1.
Diverticular disease is treated with a high-fiber diet and bulk laxatives such as psyllium hydrophilic mucilloid (Metamucil). Fiber decreases the intraluminal pressure and makes it easier for stool to pass through the colon. Bulk laxatives do not manage diarrhea, anxiety or relieve gas formation.
Which condition would disturb the hardy-weinberg equilibrium and cause the gene pool to change?
Mating occurs at random.
No mutations occur.
All genotypes on average produce an equal number of fertile adult offspring.
Several homozygous recessive individuals leave the population.
Answer: Several homozygous recessive individuals leave the population.
Why is it so important that the spinal cord intercepts messages of pain?
it’s important for the spinal cord to intercept messages of pain because the spinal cord is responsible for an automatic movement in response to a stimulus that’s called reflex, and make responding to the stimulus faster.example: putting your hand on a hot stove, 1. the receptors in your hand detect stimuli (hot temperature). they send messages through nerves to your spinal cord 2. responding nerves signals travel directly from the spinal cord to muscles in your arm, and you pull your hand away 3. AFTER you respond to the stimuli, nerve signals travel from the spinal cord to the brain, and you feel pain.
Which of the following is not considered to be a part of the endomembrane system?
A., endoplasmic reticulum
B., mitochondria
C., Golgi
D., lysosome
E., plasma membrane
Answer:
B., mitochondria
Soils composed mostly of primary minerals will tend to have a higher percentage of _____ and a lower percentage of _____ than soils composed mostly of secondary minerals.
Answer:
sand; clay
Explanation:
Soils composed mostly of primary minerals will tend to have a higher percentage of sand and a lower percentage of clay than soils composed mostly of secondary minerals.
Soils are porous medium that are made up of minerals, organic matter, water, gases, and microorganisms. Soils are mostly composed of minerals (about 45% to 49%) which are derived from two main mineral types; primary and secondary minerals. Primary minerals are usually derived from igneous and metamorphic rocks in soil, while secondary minerals are produced from the weathering of the primary minerals. Soils that contain mainly primary minerals usually have high amount of sand and silt, and a low amount of clay than soils that contain mainly secondary minerals. Examples of primary minerals are K-feldspars (such as sanidine and orthoclase), and micas (such as biotite).
Carbon dioxide levels in the blood and cerebrospinal fluid affect blood pH. This enables the organism to sense a disturbance in gas levels as ________. A. the brain directly measures and monitors oxygen levels and causes breathing changes accordingly. B. the brain alters the pH of the cerebrospinal fluid to force the animal to retain more or less carbon dioxide. C. the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing. D. stretch receptors in the lungs cause the medulla oblongata to speed up or slow breathing.
Answer:
C. the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing.
Explanation:
The central chemoreceptors are located near the medulla inside the blood-brain barrier. When CO2 in cerebrospinal fluid increases, pH of the fluid lower (because CO2 becomes hydrated to carbonic acid). Change in pH stimulates the central chemoreceptors to activate respiratory centers which will increase the respiratory rate and depth of breathing.
The medulla oblongata, in contact with cerebrospinal fluid, monitors blood pH and carbon dioxide levels to control breathing, ensuring homeostasis.
Carbon dioxide levels in the blood and cerebrospinal fluid affect the blood pH. This enables the organism to sense a disturbance in gas levels as C. the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing. The medulla oblongata is the part of the brain that detects changes in carbon dioxide levels and pH, triggering the respiratory centers to adjust the rate and depth of breathing. Faster breathing is initiated to decrease high carbon dioxide levels, which also decreases the levels of hydrogen ions, leading to an increase in blood pH. Conversely, slower breathing occurs if there is a low carbon dioxide level, which helps maintain pH levels within a normal range.
Different finch species have beaks of different shapes and sizes. What do these beak differences tell us? Different finch species have beaks of different shapes and sizes. What do these beak differences tell us? Different finch beak shapes are evidence that individual birds changed their beaks so that they could feed efficiently. Different finch beak shapes are evidence that all Galápagos finches share a common ancestor. Different finch beak shapes are evidence that finch species adapted to different environments over many generations. Different finch beak shapes are evidence that several finch species with different beak types came to the Galápagos Islands from the mainland.
Different finch beak shapes are evidence that finch species adapted to different environments over many generations.
The correct answer is C. Different finch beak shapes are evidence that finch species adapted to different environments over many generations.
Explanation:
According to Charles Darwin's proposals related to evolution, organisms that are similar such as birds or finches adapt to environmental conditions over time which explains the differences in terms of the phenotype (observable traits). This occurs in the case of finches beak shapes, as Darwin studied around 15 species of these birds in the Galapagos Islands and found finches have different sizes and beak shapes that were linked to the type of food each species consume and the source of this. Therefore, different finch beak show "that finch species adapted to different environments over many generations".
Which of the following represents the correct flow of air into the lung of a mammal?
A. larnyx → trachea → bronchi → bronchioles → alveoli
B. alveoli → tracheoles → bronchi → trachea
C. trachea → bronchioles → bronchi → alveoli
D. trachea → tracheoles → bronchi → alveoli
I believe the answer would be A.
The flow is larynx, trachea, bronchi, bronchioles, alveoli
Larnyx → trachea → bronchi → bronchioles → alveoli is the right flow of air into the lung of a mammal.
What is the pathway of the flow of air into the lungs?The most important function of the respiratory system is to obtain oxygen from the environment for the cells and eliminate the carbon dioxide by exhalation that is produced by the body.Firstly, the air enters the nasal cavity and also the oral cavity.Then it reaches the pharynx, travels to the trachea, then to both the bronchi, secondary bronchi, and tertiary bronchi. It then reaches the bronchioles and finally the alveoli where the exchange of the gases takes place.Oxygen and carbon dioxide are exchanged between the alveoli and this process occurs by diffusion.Hence, Option A is the right answer.
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Over-using an aquifer can lead to subsidence. which other hazard would most likely be exacerbated by this subsidence?
Answer:
the answer is flooding.
What conditions or disorders may mimic the symptoms of dementia a. Vitamin deficiency b. Thyroid disorder c. Medication side effect
I believe the answer is a. Vitamin deficiency.
I hope this helps!
Conditions or disorders that mimic dementia symptoms include vitamin deficiency (a), thyroid disorder (b), and medication side effects (c) is all correct .
Vitamin Deficiency (a): Deficiencies in certain vitamins, especially B vitamins like B12, can lead to symptoms that resemble dementia. These symptoms may include confusion, memory problems, and cognitive decline.
Vitamin B12 deficiency, in particular, is known for causing neurological symptoms that can be reversible with proper supplementation.
Thyroid Disorder (b): Thyroid disorders, both hyperthyroidism (overactive thyroid) and hypothyroidism (underactive thyroid), can lead to cognitive impairment and memory problems.
An underactive thyroid, in particular, can cause a condition known as myxedema madness, which mimics dementia symptoms.
Medication Side Effects (c): Certain medications, especially those with anticholinergic effects, can cause cognitive issues. These drugs are commonly used for various conditions, such as allergies, depression, and overactive bladder.
It's essential to review medication lists and consult a healthcare provider if you suspect medication-induced cognitive changes.
Depression and Anxiety: Mood disorders, such as depression and anxiety, can manifest with cognitive symptoms that mimic dementia, like memory difficulties, confusion, and impaired concentration.
Treating the underlying mood disorder can often improve cognitive function.
Infections: Infections in the central nervous system, such as urinary tract infections in older adults, can cause delirium and confusion. These symptoms can be mistaken for dementia but are reversible with appropriate treatment.
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During endocytosis and exocytosis, cells _____.
A) take in what they need and expel what they don't need
B) move water in and out through the cell membrane
C) actively transport molecules across the cell membrane
the answer is letter A
Answer:
Take in what they need and expel what they don't need. (Ans. A)
Explanation:
Endocytosis and exocytosis are two active transport processes which are helping macro molecules present in the cytoplasm to move inside or outside the cell across the plasma membrane. It is an energy requiring movement.
Endocytosis is known as a process which is capturing the particles from outside the cell by engulfing of them with the cell membrane. Endocytosis is mainly two types:
1) Phagocytosis, in this process cell is engulfing whole particle. It is also known as cell eating.
2) Pinocytosis, in this process cell is engulfing already dissolved food. It is also known as cell drinking.
Exocytosis, in this process where vesicles fusing with the plasma membrane which helping them to move substances out of the cell.
plz need help asap !!!
The cell is preparing to split. The cells are going to be equal so I'd say it's the bottom image
Which of the following pairs are the best examples of homologous structures?
(a) bat wing and human hand
(b) owl wing and hornet wing
(c) porcupine quill and cactus spine
(d) bat forelimb and bird wing
(e) Australian mole and North American mole
D. Bat forelimb and bird wing
Water that is returned to the environment after secondary treatment is known as _____. influent sludge effluent clarifier
Water that is returned to the environment after secondary treatment is known as effluent.
Answer:
effluent
Explanation:
Secondary treatment uses physical phase separation or biological methods to clean the waste water. Influent is the wastewater which enters the secondary treatment system. Clarifier is a huge tank where it is allowed to stand for solid waste particles to settle down. Sludge is the waste material which gets settled down in a clarifier. Effluent is the final product which exits the secondary treatment plant.
Which enzyme is paired incorrectly with its function? which enzyme is paired incorrectly with its function? helicase: untwists double helix single-strand binding proteins: unpair dna strands and prevent re-pairing topoisomerase: joins sugar-phosphate backbones of okazaki fragments primase: synthesizes an rna primer dna polymerase: catalyzes synthesis of new dna?
Answer:
a) DNA polymerase – catalyze the addition of dNTPs to a new DNA strand b) DNA ligase – produce RNA primers for Okazaki fragment formation DNA primase – produce RNA primer as a starting point for DNA synthesis DNA helicase – unwind DNA helix to separate strands x Telomerase – catalyze lengthening of telomeres in germ cells
If you cut a flatworm in half, both halves can grow into a new individual by _____.
If you cut a flatworm in half, both halves can grow into a new individual by fission.
If you cut a flatworm in half, both halves can grow into a new individual by FISSION.
Research shows that the vast majority of drivers are functionally impaired even at the legal limit of 0.08 blood alcohol content (bac). research shows that the vast majority of drivers are functionally impaired even at the legal limit of 0.08 blood alcohol content (bac).
a. True
b. False
The answer is A. True.
What is the first step that should be taken when a caustic chemical gets into a person's eye?
the person should wash their eye out for no less than 15 minutes
Hemoglobin's affinity for oxygen is how much oxygen is actually currently held by the hemoglobin. So, if hemoglobin has high oxygen saturation, hemoglobin's affininty for oxygen is high. What do you think happens to hemoglobin's affinity for oxygen as it moves through the systemic capillaries? As the RBC moves through the systemic capillary, hemoglobin's affinity for oxygen increases. As hemoglobin moves through the systemic capillary, hemoglobin's affinity for oxygen stays the same. As the RBC moves through the systemic capillary, hemoglobin's affinity for oxygen decreases.
Answer:
As the RBC moves through the systemic capillary, hemoglobin's affinity for oxygen decreases.
Explanation:
Red blood cells (RBC) contain hemoglobin molecule which carries the oxygen through the blood. The blood with RBC moves through the systemic capillary and deliveries oxygen to the tissue (oxygen is released from the hemoglobin into the cell of the certain tissue). So, as the RBC moves through the systemic capillary hemoglobin's oxygen saturation lowers and consequently, hemoglobin's affininty decreases.
Hemoglobin's affinity for oxygen decreases as RBC move through the systemic capillaries, thus facilitating the release of oxygen to tissues with lower oxygen concentration and higher metabolic demand.
Explanation:As the red blood cells (RBC) move through the systemic capillaries, hemoglobin's affinity for oxygen tends to decrease. This is due to the oxygen-hemoglobin saturation/dissociation curve, which shows that when the partial pressure of oxygen is high, such as in the lungs, hemoglobin has a high affinity for oxygen and is likely to be fully saturated. However, in the systemic capillaries, as oxygen is delivered to tissues, the partial pressure of oxygen within the capillaries decreases, which leads to a lower affinity of hemoglobin for oxygen. This reduction facilitates the release of oxygen to the tissues that have a lower oxygen concentration and a higher demand due to metabolic activity.
The physiological process described by the affinity for oxygen decreases is an automatic control mechanism that ensures tissues with higher metabolic demands receive more oxygen. Additionally, factors such as increased carbon dioxide concentration or a decrease in pH can further reduce hemoglobin's affinity for oxygen, favoring oxygen release.
Given two areas with equal sunlight and available water. Area I has a high amount of atmospheric carbon dioxide while Area II has a low amount of atmospheric carbon dioxide. How does the rate of photosynthesis in Area I compare to that in Area II? Atmospheric carbon dioxide has no effect on the rate of photosynthesis. The rate of photosynthesis increases with a decrease in carbon dioxide. The rate of photosynthesis increases with an increase in carbon dioxide. The level of carbon dioxide increases with the level of available oxygen.
Answer:
b
Explanation: