the membrane receptors are activated when a certain chemical attaches itself to the receptor.
Final answer:
Membrane receptors facilitate cell communication by binding to signaling molecules, triggering structural changes that lead to ion channel activation or internal signaling cascades, which can modify gene expression and cellular functions.
Explanation:
How Membrane Receptors Transmit Messages Across the Cell Membrane
Membrane receptors are specialized proteins located within the cell membrane that are responsible for transmitting messages to other cells. When a signaling molecule, or ligand, binds to a receptor on the cell's exterior, it triggers a change in the receptor's molecular structure. This alteration can either open an ion channel or activate internal signaling pathways via molecular switches. In the case of ion channels, they allow specific ions like Na+ to flow into or out of the cell, leading to an action potential. Other receptors may activate G-proteins on the cytoplasmic side, which then set off a cascade of reactions within the cell. These reactions may involve changing the permeability of the cell to certain ions or altering gene expression by affecting the transcription of DNA in the nucleus. Ultimately, these processes change the cell's activities and functions in response to the initial signal.
Can you determine which instances reflect a valid experiment or conclusion? Check only those that are valid.
a. A biology class is conducting an experiment to determine how soil pH affects the germination of pine seedlings. 30 pine seeds are placed in pots of soil with varying pH levels: 4.5, 6.5, 7.0, 7.5, 8.5, and 9.0. Pot size, water, and light exposure were constant for all pots.
b. A marine biologist is examining the effects of oil pollution on a population of seagulls (Larus canus). He is particularly interested in determining whether oil pollution reduces the number of eggs that may be hatched in each seagull nest. During one breeding season, he has counted the number of eggs present in 16 seagull nests and recorded the distance from each nest to a nearby oil refinery
c. After months of grueling research drinking many, many colas, Karl has come to the conclusion that Brand A cola tastes better than Brand B cola.
d. Jeanette was conducting an experiment to determine if plants grow better when exposed to rap music. She bought two identical plants and exposed one to rap music for two weeks while the other grew without music. From the data, Jeanette determined that plants do not grow better with rap music.
e. Robert is instructed in a lab experiment to first record the ambient temperature of the room. To do this, he holds the thermometer under a bright light to accurately read it. He then reads and records the data as 33°C.
Answer:
Only options a reflects the instances with valid experiment or conclusion.
Quality of any experiment depends upon two things reliability and validity. Reliability is measure of regeneration of results every time an experiment is performed under specific conditions.
Validity is measure of accuracy of results of an experiment. It can be check by two ways: internal validity (checks the design of the experiment) and external validity (checks if the conclusion is the real explanation of the phenomenon).
Now, in marine biologist experiment, he concluded the results only after one breeding season. This makes his results unreliable as it might have happened by chance.
Similarly, in cola experiment the taste was only checked by one candidate i.e. Karl. He might have problem in his taste buds. In addition, the temperature of cola can also affects its taste which is not taken care of in the experiment. Hence, it is not the valid experiment.
Similarly. Jeanette could use more plants for her experiment and Robert just followed only one instruction. He didn't perform any experiment.
Only options a (effect of soil pH on pine seedlings) and b (oil pollution's impact on seagull eggs) represent valid experiments due to controlled conditions and the potential for a repeatable setup. The other instances lack proper control, methodology, and objectivity, which are crucial for scientific investigations.
When determining which instances reflect a valid experiment or conclusion, it is essential to consider certain factors such as the control of variables, having a clear hypothesis, and the ability to repeat the test to draw reliable inferences. Here is the analysis for each instance provided:
a. This biology class's experiment maintains constant conditions for pot size, water, and light exposure while varying only the soil pH, providing a good setup for a controlled experiment.
b. The marine biologist has observed a potential correlation between the distance from an oil refinery and the number of eggs hatched in seagull nests, which can be further investigated by controlling additional variables.
c. Karl's conclusion lacks the rigor of a controlled experiment as taste is subjective, and no information is provided about sample size, controls, or blinding procedures. Therefore, it does not represent a valid scientific conclusion.
d. While Jeanette has a hypothesis, her experiment with only two plants and no control group for the non-musical environment is not sufficiently rigorous.
e. Robert's method for reading the ambient temperature is inaccurate, as holding the thermometer under a bright light could increase the reading, invalidating the experiment's validity.
Valid experiments must be designed to isolate variables and be repeatable, allowing for inductive reasoning to confirm hypotheses with substantial data. In the instances given, options a and b appear to be the most valid experiments.
Determine whether each statement describes mitosis, meiosis, or both mitosis and meiosis.
Final answer:
Mitosis and meiosis are both cell division processes, but they differ in their mechanisms and outcomes. Meiosis includes unique stages such as prophase I and metaphase I, where homologous chromosome pairing and crossing over occur. Metaphase is a stage shared by both processes, but it functions differently in meiosis I compared to mitosis and meiosis II.
Explanation:
Comparing Mitosis and Meiosis
Both mitosis and meiosis are processes of cell division. Mitosis consists of four stages: prophase, metaphase, anaphase, and telophase, culminating in cytokinesis. In meiosis, there are two rounds of cell division, meiosis I and meiosis II, each with similar stages to mitosis, but with important differences. Meiosis is unique in that it has the stages of prophase I and metaphase I, where homologous chromosomes pair up and undergo crossing over, and anaphase I, where these homologous pairs are separated into two cells, reducing the chromosome number by half (from diploid to haploid).
Metaphase appears in both mitosis and both meiotic divisions. However, it has a unique characteristic during meiosis I where homologous chromosomes line up in pairs; in mitosis and meiosis II, individual chromosomes line up at the metaphase plate. The behavior of chromosomes during meiosis leads to genetic variation among the four haploid cells produced, while mitosis results in the production of two genetically identical diploid cells.
Explain how organisms in lakes are related through the flow of energy.
Answer
The energy flow system in the lakes is controlled by the manner aquatic organisms interact with each other.
Explanations
In lakes and ponds there is transfer and flow of energy that depends on the manner aquatic organisms interact with each other. For example, In a simple aquatic food web, phytoplankton in form of algae and aquatic macrophytes in form of plants obtain energy from the sun and convert it to energy they can use through photosynthesis. During this process, carbon dioxide, water, sugars and energy from the sun is utilized to form organic compounds in form of chemical energy. This chemical energy is then utilized for growth and reproduction.
Answer: A food chain shows how energy flows from one organism to another. In general, energy flows from the Sun to producers and then to consumers. They get energy by eating grass and leaves. Energy may be lost in living systems as it flows through them.
Explanation: EDGE 2020
Which layer of soil is the most newly formed? A. subsoil B. humus C. topsoil D. bedrock
Answer:
No, It Humus
Explanation:
Humus is the top layer of soil and is formed by deposits of decomposed plant material. It is the newest or youngest component of the soil. Moving down through the soil, the layers get older.
what are the main differences between living cells and viruses
Cells are the basic units of life. They can exist by themselves, like bacteria, or apart of a larger organism, like our cells. Viruses are non-living infectious particles that are much smaller then a cell, and need a living host to reproduce. They cannot reproduce outside of a living host cell, nor can they be seen without an electron microscope.
The seeds of cycads develop within a A. fruit. B. pistil. C. cone. D. flower.
Answer:
The answer is D
Explanation:
use a processing method of your choice to explain how buffer systems work and why they are important to homeostasis
Altruism refers to behavior that helps others but does not appear to help the person performing the behavior. Describe an example of altruistic behavior, and state how a psychodynamic psychologist might explain the behavior.
Answer:
This is sample from Edmentum
Explanation:
There have been many occasions when people have been good to me without expecting anything in return. I think and hope that many of my actions, too, have been out of goodwill and not with any personal motive. This happened some years ago and I believe that this has inspired me to do good deeds whenever an opportunity presents itself. My mother is a single parent and this incident occurred soon after we moved to the town that we live in currently. She had to undergo an emergency operation. We didn’t have any friends or relatives in the town. The neighbors turned out to be great people. They didn’t know us but each one of them pitched in, taking turns to invite me home for meals while my mother was hospitalized, visiting my mother at the hospital, and keeping our spirits up. That week was difficult for us but during that time, we made some incredible friends.
Altruism is a behaviour in which a person help other people, just out of desire to help, without wanting anything in return.
An example of altruistic behaviour is: Suppose you are in a bus, and you see an old woman standing, and you offer her your chair, not because you have to but out of desire to help and that makes you happy.
Explanation of altruistic behaviour as a psychodynamic psychologistAltruism is defined by many disciplines. There is no single perspective regarding altruism but rather many perspectives from different psychologist.
To begin with, psychology has found many processes by which people might learn about and care about the conditions of others.
Psychology says that, though Altruism is a kind behaviour, but it's not always true that altruism will and will not lead to helping behaviour.
Altruism is a selfless behaviour, but it's sometime leads to danger to the person who help and cause the person to feel overwhelmed.
Although it is a positive behaviour and people should keep altruistic behaviour and help people.
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Translation and protein synthesis is occurring at the ribosome. If the tRNA anticodon being matched at the ribosome is AUG, what would be the matching mRNA codon?
Answer: The matching mRNA codon for AUG anticodon is - UAC.
UAC codes for tyrosine.
mRNA is converted into protein through a process called translation ( occurs in the cytoplasm of cell). During this process, tRNA ( transfer RNA) delivers specific amino acid ( carried by amino acid acceptor site of tRNA) to the ribosome that matches with the codons ( sequence of three nucleotides in mRNA).
The anticodon carried by the anticodon site of tRNA molecule is complementary ( A pairs with U and G pairs with C) to the codon present in the mRNA sequence.
Thus, UAC is the codon in the mRNA that corresponds to the anticodon AUG.
The mRNA codon that matches the tRNA anticodon AUG is UAC. This matching is based on complementary base pairing. In this case, Adenine (A) matches with Uracil (U), and Guanine (G) matches with Cytosine (C).
Explanation:In the ribosome, during protein synthesis, an mRNA codon corresponds to a matching tRNA anticodon. The anticodon and codon pairs through complementary base pairing. If the tRNA anticodon is AUG, this pairs with an mRNA codon of the sequence UAC, since Adenine (A) pairs with Uracil (U), and Guanine (G) pairs with Cytosine (C). Therefore, the mRNA codon matching the tRNA anticodon AUG would be UAC.
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Which mineral resource is used to make baby powder?
A) talc
B) gypsum
C) graphite
D) salt
a) talc Most people are familiar with the mineral talc. It can be crushed into a white powder that is widely known as "talcum powder." This powder has the ability to absorb moisture, absorb oils, absorb odor, serve as a lubricant, and produce an astringent effect with human skin.
Talc is used to make baby powder because,it absorb moisture and keeps the baby dry..
What is talc?The term talc refers to the mineral that is obtained from the soil and is used in the manufacturing of powder.
This mineral is composed of magnesium, silicon, and oxygen and has the important property of being able to absorb moisture henece it is used in baby powder.
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Which best describes the dorsal nerve cord? Help urgent
If it is a MCQ, I cannot find the propositions, I just can explain to you what's the dorsal nerve cord.
The dorsal nerve cord is one of the unique embryonic characteristics of the ganglia next to the dorsal cord. The dorsal nerve cord is a hollow dorsal cord.
It consists of a part of the exfoliated coagulant, forming a hollow tube, compared to other animal species that have solid abdominal tubes.
The dorsal nerve cord later changes in vertebrates to the central nervous system, which consists of the brain and spinal cord. The dorsal nerve cord is found mainly in the vertebrae vertebrates.
A thick grouping of nerves that runs down the back of the embryo.
List two health effects Deb is experiencing. Explain how nutritional deficiencies of certain biomolecules can cause it.
Answer:
protein and vitamin deficiency
Explanation:
Deb is very skinny and she doesn’t seem to have a lot of muscles she also complains of bleeding gums and no nail growth, which are symptoms of protein and vitamin deficiency
Answer:
Explanation:
Deb is very skinny and she doesn’t seem to have a lot of muscles she also complains of bleeding gums and no nail growth, which are symptoms of protein and vitamin deficiency
Which of the following best describes aerobic respiration?
processes that require ATP
processes that do not require oxygen and produce ATP
processes that require oxygen and produce ATP
processes that produce ATP
The production of ATP from glucose in the presence of oxygen.
So I would go with C) processes that require oxygen and produce ATP
The statement which best describes aerobic respiration is: C. processes that require oxygen and produce ATP.
Aerobic reaction can be defined as biological and chemical processes that occurs in the presence of oxygen.
Hence, an aerobic reaction requires oxygen before it can take place or occur and it produces adenosine triphosphate (ATP) as one of its end product.
In Science, some examples of an aerobic reaction include the following:
Krebs cycle. Electron transport chain.
In conclusion, an aerobic respiration refers to how the body of a living organism uses oxygen such as;
Running.Swimming.Walking. Jogging.Read more: https://brainly.com/question/12827458
Which organisms have the least amount of stored energy in an ecological pyramid
Final answer:
Quaternary consumers have the least amount of stored energy in an ecological pyramid. Primary producers have the most energy, with approximately 1,000,000 kilocalories, while quaternary consumers may only have around 1,000 kilocalories due to the energy loss at each trophic level transfer.
Explanation:
In an ecological pyramid, the organisms that have the least amount of stored energy are the quaternary consumers. If we assume that producers in this pyramid have 1,000,000 kilocalories of energy, the energy available to primary consumers will be significantly less due to the energy transfer inefficiency. Energy transfer between trophic levels is typically around 10%, meaning that only about 100,000 kilocalories are available to primary consumers.
Energy pyramids must always be upright to honor the laws of thermodynamics, specifically the first law, which states that energy can neither be created nor destroyed, and the second law, which indicates that energy transfer is not 100% efficient due to entropy. Biomass decreases from lower to higher levels due to energy loss at each transfer. Thus, primary producers have the highest biomass and energy, with these quantities decreasing at each ascending trophic level.
Therefore, higher trophic levels such as secondary, tertiary, and especially quaternary consumers will have much less energy available and consequently, less biomass. For example, in our scenario with producers having 1,000,000 kilocalories, quaternary consumers may only have around 1,000 kilocalories available to them.
Which of these carbohydrates is a monosaccharide? a)fructose b)maltosec)cellulosed)lactose
A _____________ forms as a result of lava that has cooled at the top of a volcano. A. Vent b. Caldera c. Pipe d. Chamber
Answer:
B. Caldera
Explanation:
edge 2020
One major biotic factor that effects the health of coral reefs is
The human gm. Csf gene in the mouth gm dash dsf jane buried by more than 60% in their dna sequence however the scientist place to human gene into mice it functions properly what best explains why this happens
As demonstrated by long-range mapping of restriction endonuclease recognition sequences and genomic cloning, we found that the human genes encoding interleukin 3 (IL 3) and granulocyte/macrophage colony-stimulating factor (GM-CSF) are tandemly arrayed on the long arm of chromosome 5, separated by 9 kilobases (kb) of DNA. This close physical linkage of genes with similar structure and biologic function suggests that these cytokines may have evolved from a common ancestral gene. This linkage in evolution of two relatively divergent genes further implies that some of the other lymphokine and cytokine genes that appear to share as much or more sequence similarity than do IL 3 and GM-CSF may be distantly related members of a cytokine gene family.
Red-tailed hawks prey on prairie dogs. If another species of hawk that eats prairie dogs migrates into the area, what is most likely to happen to the prairie dog population? A. It will increase exponentially. B. It will increase slightly. C. It will remain the same. D. It will decrease.
Answer: Option D
Explanation: If two kinds of organisms will feed on the same prey then the population of the prey will decrease.
Red tailed hawk prey on prairie dog as their energy source and if another species of hawk will start preying on the same dog population.
Then, the population of prairie dogs will decline very fast as both types of hawk are eating prairie dogs as their food.
In 1859, Charles Darwin described a model of how living things change over time. He described this model and the evidence that supported it in a book called On The Origin of Species. Which scientific term is used to describe a testable model that seeks to explain natural phenomena?
A) data
B) hypothesis
C) observation
D) theory
The answer is theory which is a proposed explanation whose status is still conjectural and subject to experimentation, in contrast to well-established propositions that are regarded as reporting matters of actual fact.
Answer:
D) theory
Explanation:
Theory is the set of fundamental principles of an art or a science. Theory is a synthesized opinion, it is a general notion. From the Greek theoria which in the historical context meant to observe or examine. With its evolution the term came to designate the set of ideas, the basis of a certain theme, which seeks to convey a general notion of some aspects of reality.
Theory is also a conjecture, an opinion formed before a fact. One theory attempts to explain something difficult to accomplish.
A scientific theory is the speculative part of a science, as opposed to practice. It is a consistent system formed by observations, ideas and axioms or postulates, constituting as a whole a set that tries to explain certain phenomena.
Examples of scientific theories are: Chaos Theory, Communication Theory, Knowledge Theory, Evolution Theory, Game Theory, Quantum Theory, Relativity Theory, among others.
an atom of calcium contains 20 protons. how many electrons does it have?
I am pretty sure there are 20 electrons, becuase there are the same amount of protons and electrons
Protons, neutrons and electrons. ... The number is used to arrange the elements in the periodic table, beginning with hydrogen, which has just one proton. Electrons are contained in shells around the nucleus. In a neutral atom the total number of electrons is always the same as the number of protons in the nucleus.
The Answer would be 20 electrons since protons and electrons are the same.
Describes how efficiency of cellular respiration and production of carbohydrates through photosynthesis as well as oxygen has benefitted society. Explain how the earth would appear if endosymbiosis hadn’t occurred.
Answer:
Cellular respiration is the process by which cells convert glucose into energy in the form of ATP. The process of aerobic respiration produces huge amount of ATP from each sugar molecule. Aerobic respiration takes place in eukaryotes. The reactions involved in the respiration are catabolic reactions. From the complete oxidation of one glucose molecule to carbon dioxide and oxidation of all reduced coenzymes. It generates 30-32 ATP in each cycle and used by plants, animals and humans therefore it is highly efficient and beneficial for the society. Without photosynthesis plants will not have carbohydrates for respiration.
Endosymbiosis is the hypothesis which says that prokaryotes gave rise to the first eukaryotic cell. It explains the origin of eukaryotic cell organelles such as mitochondria in animals and fungi and chloroplast in plants have evolved from prokaryotes like mitochondria has evolved from proteobacteria and chloroplast from cynobacteria. It simply defines that primitive simple organisms evolved in order to develop as complex organisms. If endosymbiosis had not occurred on earth than there would be no diversity in life forms on earth.
Describe how the integumentary system responds to differences in sunlight
The integumentary system (skin) reacts different on different sun intensity (different length exposure to sun).
For example, moderate exposure to the sunlight contributes to the production of melanin and vitamin D by the body. On the other hand, high exposure to sunlight can have negative health effects such as sunburn, which is an inflammatory response to DNA damage caused by UV radiation.
In stars that are near death, What can no longer contain fusion?
A) Electromagnetic Attraction
B)Strong Forces
C) Gravity
D) Planets
i could be wrong but my assumption for this question would be the answer of A
Option C) Gravity, not the strong nuclear, weak nuclear, or electromagnetic forces, fails to contain fusion in a dying star, potentially leading to the formation of a black hole. Gravity's overwhelming force can collapse a star's core beyond any known support, indicating its importance in both stellar life cycles and the structure of galaxies.
In stars that are near death, gravity can no longer contain fusion. In the life cycle of a star, gravity plays a crucial role in sustaining the process of nuclear fusion that powers the star. However, when a star exhausts its nuclear fuel, gravity causes the star to collapse.
For very massive stars, if the remaining mass of the star's core is more than about three times that of the Sun, no known force can prevent the star from collapsing into itself and potentially forming a black hole. A black hole's gravity is so strong that it can prevent light from leaving, which is why black holes are often detected via their gravitational effects on neighboring stars or clouds of gas and dust.
Therefore, the correct answer is C) Gravity.
Chemicals found in all cells that are used for work and growth are
_____ intake is essential in the prevention of heat related injuries
Water intake is essential in the prevention of heat related injuries
What happens to a plant that doesn’t get enough water
urgent help
What is the approximate total number of species for all life-forms on Earth?
List the approximate number of species for each of the six kingdoms.Each degree of the circle graph is equal to 10 000 species.Archaebacteria represent 1/20 of a degree, and Eubacteria represent 1 degree
Archaebacteria = 10,000/20 = 500 species
Eubacteria = 10,000/1 = 10,000 species
Do the rest the same way, since you've got the graph right in front of you.
The student measured the volume of water as 80.0 mL. she discovered that the actual volume was 80.1 mL. is her measurement accurate
Yes, her measurement is accurate.
Accuracy of a measurement is the closeness of a measured value to the actual or standard value. From the question, the first volume she measured; 80.0 ml is closer to the actual volume of water; 80.1ml. In this case, her measurement is accurate.
Answer:
OK
Explanation:
Accuracy = The fact of being exact or correct, when talking about numbers wemust always consider a variation or more or less than the stablished value. Based on that calculating quantities or volumes of liquids gives us this variation as a permited possibility, also the difference is so minimal that IT MUST BE CONSIDERED AS ACCURATE AND ACCEPTED.
The grid-like lattice of proteins that gives the cell shape and support is the _____.
A. endoplasmic reticulum
B. cytoskeleton
C. cytosol
D. cytoplasm
The right option is; B. cytoskeleton
The grid-like lattice of proteins that gives the cell shape and support is the cytoskeleton.
The cytoskeleton is a system of interconnected tubules and filaments that reach out all through the cell, from the cytoplasm. The cytoskeleton is composed of filamentous proteins, and its main function is to give the cell its shape, and mechanical support that helps the cell to perform important functions like movement and division.