Answer:
valid
Explanation:
A measurement is considered valid if it actually measures what it is intended to measure, according to the topic of the study.
Validity can be described as accuracy of something. Validity is measuring something which we are actually supposed to measure, whereas reliability shows how consistent or convenient are the results. Validity states how much accuracy is present in a statement, concept or measurement. The term 'valid' is known to be derived from a Latin word "validus" which means to be strong.
Describe the difference between negative and positive feedback mechanisms in
the body
a. Positive feedback increases the body's level of a variable while negative
feedback reduces the level of the variable
b. Positive feedback is good for the body and helps put the body back to homeostasis. Negative feedback occurs when there is a problem with the body
and it can't get back to homeostasis.
c. Negative feedback returns the body to its "normal" levels when it gets too high
or too low. Positive feedback continues to add to one side of the balance
making the change even greater.
d. Both negative and positive feedback loops work in the same way to help the
body maintain homeostasis.
Please only answer if you know the answer
Negative feedback helps achieve and maintain the set point within a system, acting as a control mechanism. In contrast, positive feedback lacks the controlling aspect and instead accelerates the direction of change. Hence, the correct option is c.
The primary difference between negative and positive feedback mechanisms in the body involves the system's response to changes. Negative feedback mechanisms work to maintain homeostasis by reversing the direction of a change when the levels of a variable become too high or too low. For example, the regulation of blood glucose levels through the release of insulin and glucagon is an instance of negative feedback: insulin lowers high blood glucose levels, while glucagon raises low blood glucose levels.
On the other hand, positive feedback mechanisms amplify the changes the system is undergoing, pushing it further away from its original state. These are less common because they could disrupt homeostasis, but they are normal and critical when there is a specific endpoint, such as during childbirth where the release of oxytocin intensifies contractions until delivery.
In short,
The Light Reaction begins in Photosystem 1.
True
True
False
Answer: False
Explanation:
The given statement is False.
The light reaction begins in photosystem 2 (PS2).
In the process of light reactions in photosynthesis energy is generated so that it can be use in the dark reactions.
During light reaction, water molecule breaks down into oxygen molecule and an electron. this free electron attains attains a higher energy level in the reaction center of photosystem 2. The state of an unstable electron undergoes an electron transport chain (ETC). The electron flows from PS2 to cytochrome and then to photosystem 1 (PS1). In PS1 the light-independent energy takes place where further electrons are transfered to NADPH.
During which phase of cell cycle do chromatids form
In the S phase (synthesis phase), DNA replication results in the formation of two identical copies of each chromosome sister chromatids that are firmly attached at the centromere region.
During which stage of mitosis do chromatids?Metaphase leads to anaphase, during which each chromosome's sister chromatids separate and move to opposite poles of the cell.
What is the S phase of the cell cycle?
Cell cycle has different stages called G1, S, G2, and M. G1 is the stage where the cell is preparing to divide. To do this, it then moves into the S phase where the cell copies all the DNA.
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Final answer:
Chromatids form during the S phase of the cell cycle, when DNA replication results in two identical sister chromatids joined at the centromere.
Explanation:
Chromatids are formed during the S phase (Synthesis phase) of the cell cycle when DNA replication takes place. In the S phase, each chromosome duplicates and creates two identical DNA molecules known as sister chromatids, which are connected at a central region called the centromere. This prepares the cell for division, whether it be mitosis or meiosis.
Subsequent stages of the cell cycle involve the movement and separation of these chromatids. During prophase and metaphase, the chromosomes condense and align for division. In anaphase, the sister chromatids are pulled apart to opposite poles of the cell, and during telophase, they arrive at opposite ends, followed by the division of the cell into two daughter cells in cytokinesis.
what do you know about an organisms parents if it is heterozygous for a certain trait ?
a. both parents supplied the same allele
b. the parents had different traits
c. the parents supplied different alleles
d. the parents have the same traits
Answer:
b. they present different traits
Explanation:
they are diffrent because heterozygous isnt allways the same.
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Multiple Choice
1. All of the following are examples of remote
sensing except
a. AUVs.
b. ROVs.
c. satellites.
d. scuba.
All the following are examples of Remote sensing devices except scuba. So the correct option is D.
What are remote sensing devices?The devices that are used to study and analyze the characteristics of an area, object, or a specific phenomenon, without any direct contact are called remote sensing devices.
The observations made by remote sensing devices are used for various kinds of studies and purposes. For example, observations by a weather satellite can be used to predict the weather.
Other applications of remote sensing devices are the study of the environment, the study of natural hazards, mapping of land use, etc.
A remote sensing device needs two main components.
Platform - It acts as a carrier to fit the sensors of the remote signal. Sensors - These receive the electromagnetic radiation and cover it to the recorded signal.Thus, except a scuba, all the others are examples of remote sensing devices.
Therefore, the correct option is D.
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Complete the following sentence: "When ionic compounds dissociate in water, each ion is surrounded by a sphere of hydration: __________ are surrounded by the partially negative charge of the water molecule's __________; __________ are surrounded by the partially positive charge of the water molecule's __________.
Answer:
Cations, Oxygen, Anions, Hydrogen
Explanation:
Water molecule is polar (meaning it has dipoles). The oxygen having a higher atomic mass attracts most of the electron cloud of the molecule becoming partially negatively charged and leaving the hydrogen end to be partially positive.
An Ionic compound is one between two atoms where one donates its electrons to the other for both to achieve stable configuration. The two atoms, therefore, become charged and are bought together by electrostatic forces.
When an ionic compound is put in water, it dissociates into its ions (anions and cations) They attract and repel with the polar water molecules depending on their charges. The anions (negatively charged ion) are surrounded by water molecules with the hydrogen ends and the cations are surrounded by water molecules with the oxygen ends.
Answer:
Positive sodium ion, oxygen atom, negative chloride ion, hydrogen are the answers
Explanation:
Water can dissolve many solutes. Water molecules are polar; however, it acts differently with charged polar substances. This interaction of water with charged substances forms hydration shell surrounding the solute. So, when the ionic compound NaCl dissociate in water, the hydration shell formation occurs around the ions.
The positively charged Na become surrounded by partially negative charge of the oxygen atom of water molecule and the negatively charged Cl become surrounded by partially positive charge of hydrogen atoms of water.
What human body system sends signals to glands in the endocrine system to release hormones?
A. circulatory system
B. excretory system
C. nervous system
D. digestive system
Answer:
a
Explanation:
In food production, what is used to
(a)
regulate the growth and ripening of fruits
Answer: Ethylene Gas
Explanation: Ethylene Gas Can be Used to Regulate Fruit Ripening Ethylene is a gas and is known as the “fruit-ripening hormone.”
a bacterial cell is 0.002 mm long. A magnified image of the cell is 18 mm long. What is the magnification?
The magnification of the bacterial cell image is 18 mm / 0.002 mm = 9000
What is the magnification?Magnification means how much bigger the image is compared to the object itself. In this situation, the picture of the tiny bacteria cell is zoomed in to be 9000 times bigger than it really is.
This means that if you were to use a microscope that makes things look 9000 times bigger, a bacterial cell would look like it is 18 mm long.
It is important to understand that making an image bigger does not make it clearer. Resolution means the skill to see the difference between two points that are very close together. To make an image clearer, use a microscope with a bigger number called numerical aperture (NA).
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How does the angle of sunlight affect the climate of each of the climate zones?
Sunlight angle shapes climate zones: shallow angles cause cold polar climates, varying angles lead to temperate fluctuations, direct angles create tropical heat, and changing angles result in arid extremes.
The angle of sunlight significantly influences the climate of each climate zone. In polar zones, where the angle is shallow, sunlight is spread over a larger area, resulting in lower temperatures. In temperate zones, varying angles across seasons cause temperature fluctuations. Near the equator, where sunlight strikes directly, tropical climates experience high temperatures.
Subtropical zones have consistent, intense sunlight, yielding warm climates. The angle's changing inclination in arid zones leads to extreme temperature shifts. Lastly, in high-altitude regions, steep angles result in cooler temperatures. Overall, sunlight angle affects the distribution of heat, playing a pivotal role in determining the temperature and characteristics of each climate zone.
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Final answer:
The angle at which sunlight strikes Earth, influenced by its 23.5-degree axial tilt, results in the differing climate zones across the globe. Direct sunlight near the equator leads to a warmer climate, while increased reflection near the poles causes cooler conditions.
Explanation:
The angle of sunlight plays a critical role in shaping the climate of various zones on Earth. The Earth's 23.5-degree axial tilt leads to variations in sunlight exposure throughout the year. During the summer season in either hemisphere, the tilt is such that the Sun's rays hit the Earth at a more direct angle, leading to increased solar energy absorption and warmer temperatures.
Conversely, during the winter, the tilt causes the Sun's rays to strike the Earth at a sharper angle, resulting in less energy absorption and colder conditions. The regions closest to the equator receive the most direct sunlight, which leads to a warmer climate year-round. In contrast, the poles are characterized by an increased angle of incoming solar radiation, leading to more reflected sunlight and a cooler climate. The culmination of these factors influences the distribution of the Earth's climate zones.
When a honey bee stings or a pathogen attacks, the body elicits an inflammatory response. Label the processes that happen during an inflammatory response.
Answer:
Honey bee or pathogen attacks by penetrating chemical components in the body, eliciting inflammation.
Explanation:
Honey bee stings with the barbed stinger located at the end of its abdomen which penetrates the skin in order to inject the venom from his venom sac consisted of organic molecules and proteins. This can cause pain, swelling and inflammation.
The methanoic acid in its venom causes the inflammation. Pathogens penetrate mechanical components in plants that affect the mechanisms of the plant.
What is the correct definition of speed?
Answer: Speed: the rate at which someone or something is able to move or operate.
Answer:
The speed is defined as the rate at which a particular object covers a certain amount of distance. This speed can be fast or slow. An object covering a great distance in short period of time indicates a high speed and an object covering small distance in a large period of time depicts a slow speed.
This can be mathematically calculated.
Speed= Distance/Time
The unit of speed is meter/second. It can also be written as m/sec.
is a process that’s absent in cellular respiration in anaerobic organisms but present in aerobic organisms. is a process that doesn’t require oxygen.
Answer:
The krebs cycle
Explanation:
Answer:
1. Krebs cycle, 2. Glycolysis
Explanation:
don't kn ow if the first one is correct but the second one is definitely correct.
What is the best description of the word ‘recessive’ as it is used in biology?
Answer: c an allele that is only express if two versions of it are present in a cell
Explanation:
What is the role of the plasma membrane in facilitated diffusion & how is it different form osmosis?
Answer:
osmosis or diffusion. ... It is a process called facilitated diffusion. It could be simple as bringing in a glucose molecule. Since the cell membrane will not allow glucose to cross by diffusion, helpers are needed. Plasma , The primary function of the plasma membrane is to protect the cell from its surroundings.
A scientist measures 1062 mL of a substance with a density of 0.023 g/mL. What is the
mass of the substance?
Answer:
Mass of the substance is 24.426 g.
Explanation:
Given that the density is [tex]0.023g/mL[/tex]
The volume of substance is [tex]1062 mL[/tex].
density of a substance is the mass of the substance per unit volume.
density= [tex]\frac {mass}{volume}[/tex]
In this question the mass of the substance is [tex]0.023g/mL[/tex]
Therefore the mass of the substance in [tex]1062 mL[/tex] of the substance is given by
mass = [tex]volume \times density[/tex]
mass = [tex]1062 \times 0.023=24.426 g[/tex]
Final answer:
Using the formula mass = density × volume, the mass of the substance with a given density of 0.023 g/mL and volume of 1062 mL is calculated to be 24.426 grams.
Explanation:
The student has asked to calculate the mass of a substance given its volume and density. The formula to find mass is mass = density × volume. Given that the density is 0.023 g/mL and the volume is 1062 mL, we can find the mass by multiplying these two values:
Mass = Density × Volume = 0.023 g/mL × 1062 mL = 24.426 g
Therefore, the mass of the substance is 24.426 grams.
Complete this sentence: The activities of enzymes depends on the __________, __________ conditions, and the __________ of the surroundings.
Answer:
The activities of enzyme depends on the temperature, ionic conditions and the pH of the surroundings.
Explanation:
Effect of temperature on enzymes
Enzymes show low level of functioning at lower temperatures. As the temperature is raised, the activity of the enzyme increases. The enzyme activity becomes optimal at a specific temperature. Beyond this temperature, the enzyme's activity rate starts to decline until it gets denatured.
Effect of ionic conditions on enzymes
Studies show that certain enzymes require some cations for functioning. But an increased amount of cations or anions can inhibit the functioning of the enzymes.
Effect of pH on enzymes
Each enzyme has an optimum pH at which it works best. If the pH is increased or lowered than this optimum pH, then the activity of the enzyme starts declining until it gets denatured. Most enzymes work best at pH 7.0
What are the main differences between plant and animal cells?
Animal cells have a large central vacuole.
Animal cells have rough endoplasmic reticulum.
Plant cells are more rigid due to the cell wall.
Plant cells have smooth endoplasmic reticulum.
Answer:
C
Explanation:
A difference between plant cells and animal cells is that most animal cells are round whereas most plant cells are rectangular.Plant cells have a rigid cell wall that surrounds the cell membrane
The main difference between plant and animal cells is option three, Plant cells are more rigid due to the cell wall.
There are many things that are different between plant and animal cells. Some things plants have that animal cells do not are:
Cell wallChloroplastsLarge central vacuolePlastidswhile animal cells have centrioles and lysosomes that plant cells do not have. However, both cell types have rough and smooth endoplasmic reticulum.
Plant cells have a cell wall that makes their cells more rigid, gives the cell more protection, and enables it to do many things. This cell wall is not found in animal cells. This is the main difference between plant and animal cells.
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Cell structures that provide energy to the cell are called
Cell structures that provide energy to the cell are called mitochondria found in eukaryotic cells found in animals, plants, fungi, and many single-celled organisms
What are mitochondria and how does it provide energy to the cellMitochondria are specialized structures found in eukaryotic cells. They are often referred to as the "powerhouse" of the cell because they are responsible for producing most of the cell's energy in the form of ATP (adenosine triphosphate).
The process of energy production in mitochondria is called cellular respiration. It involves a series of chemical reactions that take place in the inner membrane and matrix of the mitochondria. During cellular respiration, glucose and other molecules are broken down to release energy. This energy is then used to produce ATP, which can be used by the cell for various function
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The effector of a feedback mechanism is usually which part of the body?
A) skin
B) brain
C) gland
D) stomach
Answer:
Your answer is B) Brain
Answer:
B) brain
Explanation:
Feedback mechanisms are actions capable of controlling the body's homeostasis (balance).
The brain has the main role in these processes, promoting antagonistic actions, dividing into positive and negative feedbacks, such as the increase or decrease in body temperature or blood glucose level, for example.
Positive feedbacks act to amplify actions that promote changes in the body, while negative feedback acts to reverse changes that have occurred. These are more common than the positive ones.
which organism is NOT made up of 1or more eukaryotic cells?
A.) a dog
B.)dandelion
C.)radiolarian
D.)methanogen
Answer:
D
Explanation:
Methanogens are prokaryotes and therefore have prokaryotic cells. They are single-celled archaea. They are found in hypoxic conditions like the first stomach of ruminants where they digest molecules like cellulose and produce methane as a byproduct. The rest are composed of eukaryotic cells which are much larger than prokaryotic cells and their organelles are membrane-bound (unlike prokaryotes).
An atom of the element zinc has an atomic number of 30 and a mass number of 65. How many protons does an uncharged zinc atom have?
the element zinc has 30 protons
Explanation:
Atomic number is the sum of all the number of protons present in an element. And, mass number is the sum of total number of both protons and neutrons present in an element.
When an atom is neutral in nature then its number of protons is equal to its number of electrons.
Since, it is given that atomic number of zinc is 30 so, it means that number of protons will also be 30.
Thus, we can conclude that there are 30 protons in an uncharged zinc atom.
Describe the factors that affect the paths of secondary succession.
Answer:
Human disturbances such as clear-cutting can also cause secondary succession. Some disturbances affect only a small area, like the local damage caused by a single tree falling in the forest, while others affect entire landscapes. These disturbances damage the ecosystem but leave soil and nutrients behind.
Explanation:
Trust me.
Compared to primary ecological succession, secondary ecological succession experiences less resource conflicts. In this succession process, the pioneer species also enjoy greater privileges.
What is secondary succession?Secondary succession starts with a lot of resource availability, primary succession starts with a crisis in resource availability. Major sources of plant energy include decomposing organic matter, inorganic salts, ions, humus, and other soil leftovers.
Pioneer species carry out the establishment or re-establishment process of the sterile or devastated ecosystems at the start of both primary and secondary successions.
Only plants and blue-green algae/cyanobacteria are the main succession's pioneer species; they are all "photo-auto-lithotrophs," or succession producers. Secondary succession pioneer species don't always have to be photo auto-lithotrophic.
Therefore, Compared to primary ecological succession, secondary ecological succession experiences less resource conflicts. In this succession process, the pioneer species also enjoy greater privileges.
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Which of the following is NOT a unique property of water?
A) Surface tension
B) It’s powerful solvent
C)Ice is less dense than water
D)It only exists in liquid and solid form.
Surface tension is NOT a unique property of water. Option A
Properties of waterThe unique properties of water are as follows:
Water is polarWater is an excellent solventWater has high heat capacity.Water has high heat of vaporizationWater has cohesive and adhesive propertiesWater is less dense as a solid than as a liquid.Learn more about water:
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Final answer:
Option D) 'It only exists in liquid and solid form' is NOT a unique property of water since water also exists as a gas (water vapor). The other options correctly describe water's high surface tension, its ability as a powerful solvent, and the lower density of ice compared to liquid water, all of which are unique properties of water.
Explanation:
The question asks which of the following is NOT a unique property of water. The options provided touch upon various characteristics of water, but the correct answer is D) It only exists in liquid and solid form. This statement is not true because water can also exist as a gas, namely water vapor. The other options represent some of the unique properties of water:
A) Surface tension: Water has a high surface tension, allowing it to form droplets and enabling insects like water striders to walk on its surface.
B) It's a powerful solvent: Water is known as the universal solvent due to its polarity, which allows it to dissolve many different substances.
C) Ice is less dense than water: This unique property is due to the hydrogen bonding in water, which causes ice to float in liquid water and is critical for sustaining aquatic life in cold environments.
By examining these properties, we can see that option D is the one that is not true about water.
which of these is not a way that carbon cycles through the biosphere A) photosynthesis B) transpiration C) combustion of fossil fuels D) decomposition
Answer:
B
Explanation:
Transpiration is a way that carbon cycles through the biosphere.
Transpiration is a process that involves loss of water through the stomata of plants.It enhances nutrient uptake from soil into plants.What is carbon cycles?The carbon cycle is the process in which carbon atoms continuously travel from the atmosphere to the Earth and then back into the atmosphere.
There are six main processes in the carbon cycle:
Photosynthesis.Respiration.Exchange.Sedimentation.Extraction.Combustion.Hence, B option is correct.
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When listing the levels of organization in organisms from smallest to most complex which level is just below organs in complexity?
Which best compares body cells and sex cells?
O Both body cells and sex cells are formed through mitosis.
O Both body cells and sex cells are produced from a diploid cell.
O Both body cells and sex cells involve one cell division of the nucleus.
* Both body cells and sex cells are involved in producing a zygote.
Its B. Both body cells and sex cells are produced from a diploid cell.
Answer:
B
Explanation:
Correct in edge 2020
What makes the tea with milk and lemon curdle?
Answer:
The tea with milk and lemon curdles due to the acidic nature of lemon.
Explanation:
Milk is made up of a number of proteins like casein. The proteins in milk are denatured by the addition of lemon juice. When lemon juice is added to tea or milk, the proteins such as the negatively charged casein become neutralized. Now, as no negative charge is present on them so they start to crumple together rather then pushing each other apart. Hence, the clumping causes the milk to curdle in tea.
Answer:
because of the acidic nature of the lemon
Explanation:
Please select the word from the list that best fits the definition
apparent movement of a star used to measure its distance from Earth
parallax
light-year
main sequence
H-R diagram
white dwarf
fusion
elliptical galaxy
barred spiral galaxy
irregular galaxy
Milky Way Galaxy
Answer: parallax is the best answer
Answer:
The correct answer is the option 1: Parallax
Explanation:
Parallax is the name given, in the field of physics, to the term that refers to the alternation or displacement in the apparent position of an object that is being watched between two different lines of sight and being measured at the same time by the angle of those two lines. In addition, that statement declares the well known ''principle of parallax'', which is used by the astronomers to measure large distances, such as the example of the question of the apparent movement of a star used to measure its distance from the Earth.