Answer: The PT and APTT are valuable blood clotting time determination principles.
Explanation:
The principle of PT or prothrombin test determines the time required for the clot formation when additional calcium factor is added.
The principle of APTT or activated partial thromboplastin time is a test which determines the time required for the formation of the blood clot after the adding the calcium and phospholipid factors. This process activates the different blood clotting factors in the blood responsible for clotting of blood.
Question 21
As human migrated away from the equator, what may have been a selective
pressure against more melanin?
Cold weather and too much body hair
Lower UV radiation and more DNA mutations
Higher UV radiation resulting in more vitamin D synthesis
Lower UV radiation resulting in less vitamin D synthesis
Answer:
Higher UV radiation resulting in more vitamin D synthesis.
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Explanation:
Vitamin D is the sunshine vitamin that has been produced on this earth for more than 500 million years.
Vitamin D is the sunshine vitamin that has been produced on this earth for more than 500 million years.During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UV B radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3.
PLEASE HELP WILL AWARD BRAINLIEST!Which of the following processes occurs when nuclei begin to surround the chromosomes on either end of the pole during Meiosis l?
1)Prophase 1
2)Metaphase 1
3)Anaphase 1
4)Telophase
Answer:
Anaphase 1 occurs when the nuclei begin surrounding chromosomes on either end of the pole.
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Which of the following is an example of an adaptation?
Answer:
B
Explanation:
The butterfly formed those adaptions so predators are less likely to eat it
hope this helps
Which one of the kingdoms is not characterized by eukaryotic cells
Answer:
Eukaryotic organisms that cannot be classified under the kingdoms Plantae, Animalia or Fungi are sometimes grouped in the kingdom Protista.
Explanation:
Will give brainliest!!!!!!
Which cerebral lobe is represented by the label B? (2 points)
Temporal
Frontal
Occipital
Parietal
Answer:
Temporal.
Explanation:
C is frontal lobe, A is cerebellum, D is parietal and the unlabeled one is occipital.
Answer:
A. Temporal.
Explanation:
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What in the cell carries genetic
information?
Answer:
chromosomes
Explanation:
I need help with this
Answer:
Horses slowly developed over time.
Explanation:
The diagram shows the evolution of horses - how they slowly developed over time. Just like humans and other species, they didn't appear suddenly. They had to go through many stages of development, from the existence of the hyracotherium, their extinct ancestor, to today.
The rest of the options are incorrect as:
As previously mentioned, new species don't just suddenly appear.There is nothing about embryological development in the given diagram.There is nothing about other hooved animals in the given diagram.How does a primary air pollutant become part of the atmosphere.
Write a 3-5 sentence summary. Looking back at the central question, what do you think would happen to a skeleton if paleontologists were not careful with how they combined the fossils they found to re-create an animal’s skeleton? Explain which parts of your hypothesis were correct or incorrect. What did this experiment reveal about God or His creation?
Answer:
Fossils are the preserved remains or traces of animals, plants, and other organisms from the past. Fossils are important evidence for evolution because they show that life on earth was once different from life found on earth today.Explanation:
Write a 600 word report discussing nuclear reactors. The report should include a description of the way a reactor works and the theory behind nuclear reactions. Be sure to answer these questions: What are breeder reactors? How are they different from regular nuclear reactors? What are their advantages and disadvantages?
Answer:
Explanation:
A nuclear reactor is an installation capable of initiating, maintaining and controlling the chain fission reactions that take place in the reactor core, consisting of the fuel, coolant, control elements, structural materials and moderator in the case of nuclear thermal reactors.
The core is the part of the reactor where the nuclear chain reaction is produced and maintained.
Components of the core:
The fuel of a nuclear reactor is fissionable material.
Control rod beams provide a rapid means of controlling the nuclear reaction, allowing rapid changes in reactor power and eventual shutdown in case of emergency.
The neutrons produced in fission have a high energy in the form of velocity. Their speed should be reduced to increase the probability of other atoms fissioning and not to stop the chain reaction. This is achieved by elastic collisions of the neutrons with the nuclei of the moderator.
Most of the energy released by fission is in the form of heat. To be able to use this, a refrigerant must pass through the interior of the reactor that absorbs and transports this heat.
In a nuclear chain reaction, a certain number of neutrons tend to escape from the region where it is produced. This neutron leakage can be minimized by the existence of a reflecting medium, thus increasing the efficiency of the reactor.
When the reactor is in operation, a large amount of radiation is generated. Protection is needed to isolate the installation workers from radiation caused by fission products. Therefore, a biological shield is placed around the reactor to intercept these emissions.
A breeder reactor is a nuclear reactor that generates more fissile material in the fuel than it consumes. Considered highly attractive because of their superior fuel economy: a normal reactor consumes less than 1% of the natural uranium that starts the fuel cycle, while a 'breeder' can burn it almost completely. It also generates less waste for the same amounts of energy. Breeders can be designed to use thorium, which is more abundant than uranium. Currently, there is renewed interest in both breeder designs due to the increased price of natural uranium.
All commercial reactors breed fuel, but they have low (though still significant) breeding ratios when compared to machines that are traditionally considered breeders. In recent years, the commercial energy industry has been emphasizing high burn fuels, which last longer in the core of the reactor.
Reproduction of fissile fuel is a common feature in reactors, but commercial reactors are not optimized for this feature which is referred to as improved burning. Up to one-third of all electricity produced in the current U.S. reactor inventory comes from reproducible fuel, and the industry is working hard to increase that percentage over time.
The advantages are:
Generates a large amount of electricity
No production of greenhouse gases
Dependence on oil is reduced
Less damage to the environment
A major disadvantage is the difficult management of the nuclear waste generated.
Nuclear power plants have a limited lifetime. The investment for the construction of a nuclear plant is very high.
Based based on the model what will the mean diameter of the phytoplankton cells that are found 25 km from shore
Answer:
650 micrometers
Brainliest?
Explanation:
Choose all the right answers. Animals cells do not need:
a cell membrane
chloroplasts
a cell wall
a nucleus
Answer:
chloroplasts and cell wall
Explanation:
These are only found in plant cells.
which statement best describes the relationship between an alleles frequemcy and its dominance
Answer:
Frequency results from environmental stresses, not dominance.
i need help now.
pls.
which is a tissue?
Answer:
C
Explanation:
even though it looks like an average guy your skin is a tissue, you can also hover over it and says what the pictures are.
Answer:
c
i did the test
lol
hope it helps
Explanation:
Help?
The model bellow shows a process that occurs in the human body (the question then shows the following image and then continues).
Based on this model, which of the following statements is true about the energy stored in the ATP molecule?
A. ATP is absorbed in the cytoplasm by the glucose and transported through the mitochondria.
B. ATP is converted to oxygen and passes through the mitochondria.
C. ATP is created when water and carbon dioxide combine in the cytoplasm.
D. ATP is released from the glucose when it is broken down in the cytoplasm and the mitochondria.
Answer:
A. ATP is absorbed in the cytoplasm by the glucose and transported through the mitochondria.
Explanation:
Good morning, can someone please help me ? Thanks
Answer:
Mitochondria.
Hope this helps.
Explanation:
Answer:
Cell Wall
Explanation:
The cell wall is a layer, that is non-living, and is part of a plant cell.
Let me know if you want me to explain more, hopefully that helps and have a great day!
Mercury's iron core takes up a majority of the planet's radius,
which plays a role in the planet's density.
TRUE
FALSE
Answer:
I think false sorry if wrong
how do the fundamental forces work together in a roller coaster
Answer:
Atoms themselves are composed of three different types of particles—protons, neutrons, and electrons. A proton carries one unit of positive† charge (Dufay's vitreous electricity) and an electron carries one unit of negative charge (Dufay's resinous electricity). A neutron carries no charge; it is neutral.
Explanation:
why is it beneficial for DNA to transition from free floating DNA to a chromosome form during the cell cycle?
Answer:
During the cell cycle, the transition of DNA from its free form to chromosome is beneficial because it allows the equitable division and transmission of genetic information to the daughter cells.
Explanation:
In eukaryotic cells, DNA contains all the genetic information of an individual and is found in the cell nucleus. The way the DNA is found while the cell is in interphase —period without division— is free form, associated with histone proteins, called chromatin.
When cell division occurs, the DNA must replicate and right at the beginning of the division process the chromatin condenses, forming chromosomes. These chromosomes contain the genetic information compartmentalized into genes, making it easier to distribute it equally to each daughter cell.
The main benefit of the condensation of chromatin - nuclear DNA - into chromosomes is to achieve the equitable distribution of genetic information and its transmission to each daughter cell.
which of the following best describes the conditions on earth over 4 bilion years ago?
Answer:
Based on the very old zircon rock from Australia we know that the Earth is at least 4.374 billion years old.
During which process do water molecules bond with elements in the minerals that make up rock to form new substances or solutions?
A. Hydration
B. Hydrolysis
C. Abrasion
D. Deflation
Answer:
A.) Hydration
Explanation:
hydrolysis is when you pass a current through water and break the molecules apart, abrasion is using an abrasive to cut material off, and deflation is taking a gas out of something. also if you think about how they word it, the waters kinda dissolving the rocks, what's another way to describe something dissolving in water, or soaking it all up...hydration
Answer:
Hydration
Explanation:
During hydration, water molecules are added to existing bonds without breaking them. Hydrolysis breaks the existing bonds. Deflation and abrasion are processes related to wind erosion.
At what site on the enzyme are reactants brought together
during a chemical reaction?
Explanation:
Enzymes bring reactants together so they don't have to expend energy moving about until they collide at random. Enzymes bind both reactant molecules (called the substrate), tightly and specifically, at a site on the enzyme molecule called the active site
The site on the enzyme at which reactants are brought together during a chemical reaction is known as the active site.
What are Enzymes?Enzymes may be defined as biocatalysts that increase the rate of a chemical reaction without being consumed or changed in the overall process. It may be thought that all cellular reactions and processes are mediated by enzymes.
The construction of the enzyme-substrate complex is the first step in the mechanism of enzymatic catalysis. In this step, the reactant molecules are brought together during a chemical reaction. These reactant molecules bind to the active site of an enzyme.
The Active site of an enzyme is the region where substrates bind and catalysis initiates.
Therefore, the active site is the region on the enzyme at which reactants are brought together during a chemical reaction.
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When is it possible to break even in an energy transformation
A: Always
B: Late phase
C: Early Phase
D: Never
A researcher conducts an investigation on fiddler crabs to understand the importance of claw size in mating. Male fiddler crabs have one normal-sized claw and one giant claw that they wave to attract female fiddler crabs. The female fiddler crabs have two small, same-sized claws. The researcher places 15 male crabs with different sized claws into an enclosure with similar conditions similar to their natural habitat. The researcher then releases 15 female crabs into the enclosure. The graph shows the percentage of male crabs of different claw size that successfully mated for three successive trials.
Answer:
The Answer is B
Explanation:
I got it right on USA TEST PREP
16. Based on the graph, what is the carrying capacity for crabs in the area being studied. Propose a reason that the population dropped in 2010
Why do these scientists use bioluminescence in their “superbugs? In this particular lab, how can they tell if the cells aren’t alive anymore?
Answer:
Not entirely positive but I do know that bioluminescence is a natural substance found in many living creatures and it makes them glow. They could be testing products for ideas of what undiscovered life is on earth. But all I do know is bioluminescence is an ingredient that causes things to glow.
Explanation:
Bioluminescence refers to a living thing that produces and emits light. Glow-in-the-dark animals can be found in all marine ecosystems, including those at the ocean's surface and deepest depths.
What is bioluminescence?Utilizing bioluminescent bacteria, they can swiftly determine the quantity of bacteria present and end the experiment much more quickly, resulting in less pain, a shorter experiment duration, and the usage of fewer animals.
Current applications of the bioluminescence reaction include gene assays, the detection of protein-protein interactions, high-throughput screening (HTS) for drug development, hygienic monitoring, the assessment of environmental contamination, and in vivo imaging of tiny mammals.
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How can a single fertilized egg cell generate so many different cell types?
what type of consumer is the scorpion?
Answer:
a carnivore
Explanation:
a carnivore, but to be more specific, a secondary consumer.
Why are triceps brachii called triceps brachii and biceps brachii called biceps brachii?
Answer:
The Triceps Brachii muscles are located on the back of the humerus and more commonly referred to as the triceps. They derive their name from a Latin phrase meaning “three headed arm muscle”, due to the fact that the triceps muscles have three muscle heads and therefore have three separate origin attachment points.
Explanation: