Answer:
From Red Giant to Supernova: The Evolutionary Path ofHigh Mass Stars. Oncestars that are 5 times or moremassive than our Sun reach the red giant phase, their core temperature increases as carbon atoms are formed from the fusion of helium atoms. ... When the core contains essentially just iron, fusion in the core ceases.
Answer:
Educators' Corner
Background: Life Cycles of Stars
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The Life Cycles of Stars: How Supernovae Are Formed
It is very poetic to say that we are made from the dust of the stars. Amazingly, it's also true! Much of our bodies, and our planet, are made of elements that were created in the explosions of massive stars. Let's examine exactly how this can be.
Life Cycles of Stars
A star's life cycle is determined by its mass. The larger its mass, the shorter its life cycle. A star's mass is determined by the amount of matter that is available in its nebula, the giant cloud of gas and dust from which it was born. Over time, the hydrogen gas in the nebula is pulled together by gravity and it begins to spin. As the gas spins faster, it heats up and becomes as a protostar. Eventually the temperature reaches 15,000,000 degrees and nuclear fusion occurs in the cloud's core. The cloud begins to glow brightly, contracts a little, and becomes stable. It is now a main sequence star and will remain in this stage, shining for millions to billions of years to come. This is the stage our Sun is at right now.
As the main sequence star glows, hydrogen in its core is converted into helium by nuclear fusion. When the hydrogen supply in the core begins to run out, and the star is no longer generating heat by nuclear fusion, the core becomes unstable and contracts. The outer shell of the star, which is still mostly hydrogen, starts to expand. As it expands, it cools and glows red. The star has now reached the red giant phase. It is red because it is cooler than it was in the main sequence star stage and it is a giant because the outer shell has expanded outward. In the core of the red giant, helium fuses into carbon. All stars evolve the same way up to the red giant phase. The amount of mass a star has determines which of the following life cycle paths it will take from there.
diagram of the life cycles of low and high-mass stars
The life cycle of a low mass star (left oval) and a high mass star (right oval).
The illustration above compares the different evolutionary paths low-mass stars (like our Sun) and high-mass stars take after the red giant phase. For low-mass stars (left hand side), after the helium has fused into carbon, the core collapses again. As the core collapses, the outer layers of the star are expelled. A planetary nebula is formed by the outer layers. The core remains as a white dwarf and eventually cools to become a black dwarf.
On the right of the illustration is the life cycle of a massive star (10 times or more the size of our Sun). Like low-mass stars, high-mass stars are born in nebulae and evolve and live in the Main Sequence. However, their life cycles start to differ after the red giant phase. A massive star will undergo a supernova explosion. If the remnant of the explosion is 1.4 to about 3 times as massive as our Sun, it will become a neutron star. The core of a massive star that has more than roughly 3 times the mass of our Sun after the explosion will do something quite different. The force of gravity overcomes the nuclear forces which keep protons and neutrons from combining. The core is thus swallowed by its own gravity. It has now become a black hole which readily attracts any matter and energy that comes near it. What happens between the red giant phase and the supernova explosion is described below.
which tissue provides support for rhubarb
Answer:
I think the answer is sclerenchyma tissue
An ionic bond is formed as the result of a
Answer:
as a result of an atom, typically a metal, losing an electron, and becomes a positive ion or cation
3. Which of the following parts of the human body is most complex?
A.
heart
B.
kidney
C.
white blood cell
D.
central nervous system
]
In these chemical compounds, C is for carbon, O is for oxygen, N is for nitrogen, and K is for potassium.
Which chemical compound is most likely inorganic?
O H₂O
OCH1
Answer:
the firt one.
Explanation:
it lacks the thing that makes organic things.
ahaha<3 still more questions luv
Answer:
organism, the leopard frog is an organism made up of other tissues and organs.
3 The graphs show the reaction rate for an enzyme across a range of temperatures and pH.
Enzyme Reaction Rates
Rate of Reaction
inn
n
0
8
10
12
10 20 30 40
Temperature (°C)
Based on these data, this enzyme functions best at what temperature and pH?
A Temperature of 27°C and a pH of 4
B Temperature of 37°C and a pH of 6
C Temperature of 40°C and a pH of 8
D Temperature of 50°C and a pH of 10
Which of the following is a central idea of cell theory? (5 points)
All living things are made of at least two cells.
O Cells cannot live alone as single organisms.
O All living things have five or more types of cells.
Cells are the basic unit of structure and function in living things.
help !!!!!!!!!!!!!!!! Ik the answer doe hehe
Toddlers and preschoolers may nap:
On beds, mats, or cots.
On beds.
In cribs.
On nap mats.
On cots.
Answer: mats and cots well at least in school at home i would see them sleeping in beds
What are the three steps scientists take to evaluate a scientific explanation?
Make an observation.
Ask a question.
Form a hypothesis, or testable explanation.
Make a prediction based on the hypothesis.
Test the prediction.
Iterate: use the results to make new hypotheses or predictions.
which one of the followin is not an organic compound
There is no option/choice to choose
Consider the following events that take place when rip
currents occur.
Which list shows the order of events in the productie
rip currents?
A. Waves travel to the beach.
B. Waves are trapped by the sandbars.
C. Waves reach the shore and go back to the ocean.
D. Waves speed up and flow between the sandbars.
E. Waves are broken by the sandbars.
O A, B, C, D, E
O A, D, C, B, E
O A, E, C, B, D
O A, E, C, D,B
Answer:
Its C, I took the quiz.Explanation:
Sorry this is lateAnswer:
c
Explanation:
Describe the differences and similarities between mitosis and binary fission.
Answer:
Binary fission is a method of asexual reproduction which single-celled organisms, usually prokaryotes, use to create a copy of themselves. Another term for the process is cellular cloning. Mitosis is cell division that results in two identical daughter cells and is primarily used for growth of an organism.
Explanation:
Binary fission has been known as method of asexual reproduction which single-celled organisms, usually prokaryotes, use to create a copy of themselves. Another term for the process is cellular cloning.
What is mitosis?Mitosis is cell division that results in two identical daughter cells and is primarily used for growth of an organism.Chromosomes are generally seen below a mild microscope best for the duration of the metaphase of molecular division.
The chromosomes are separated by a structure called the mitotic spindle. A chromosome is a lengthy DNA molecule with component or all of the genetic material of an organism. In maximum chromosomes the very lengthy skinny DNA fibers are lined with packaging proteins; in eukaryotic cells the maximum vital of those proteins are the histones.
These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to keep its integrity. These chromosomes show a complicated third-dimensional structure, which performs a large position in transcriptional regulation. Chromosomes are generally seen below a mild microscope best for the duration of the metaphase of molecular division.
Therefore, Binary fission has been known as method of asexual reproduction which single-celled organisms, usually prokaryotes, use to create a copy of themselves. Another term for the process is cellular cloning.
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In the fluid Mosaic model, the cell membrane is made of two kinds of Molecules?
Answer:
The fluid mosaic model describes the cell membrane as a tapestry of several types of molecules (phospholipids, cholesterols, and proteins) that are constantly moving. This movement helps the cell membrane maintain its role as a barrier between the inside and outside of the cell environments.
Explanation:
Given the DNA sequence 3'TACCGAGGCATT 5' what is the complementary strand sequence?
Answer:
′UACCAAGGUAG5
Explanation:
DNA is a two-stranded molecule. Each strand is a polynucleotide composed of A (adenosine), T (thymidine), C (cytidine), and G (guanosine) residues polymerized by "dehydration" synthesis in linear chains with specific sequences. Each strand has polarity which runs from 5′ to 3′.
In DNA, A pirs with T and G pairs with C.
Fo through the original 5′ to 3′ sequence pairing each A with T ad each C wth G.
While RNA is a single strand molecule. This Strand also consists polynucleotide composed A, C, G and U (uridine).
For a complementary strand replace A with U (because RNA does not consist T), T with A, C with G, and G with C.
Hence,
Given strand: 5′ATGGTTCCATC3′
Complementary RNA strand: 3′UACCAAGGUAG5′
Keep in mind that the complementary strand will read from left to right in the 3 to 5 direction.
A student is conducting an investigation to find out which food his dog likes best. Which is the dependent variable in his investigation
Answer:
the dependent vaiable would be the dog. the independent would be the type of food you are using. the independent vaiable is something you can change and you can not change the dog.
A potassium ion (K+) would most likely bond with
What organelle would you not find in a plant cell? Chloroplasts,centrioles,central vacuole,or cell wall?
Answer:
Centrioles
Explanation:
If we look at ths other options Chloroplast and Cell Wall are both needed for a plant to survive and function. So we automatically know that it's going to be there so those aren't an option. We know that both animal and plant cells have a vacuole but plant cells have larger ones so we know that's not an answer. Leaving us with the only other possible answer left, Centrioles.
Answer:
Hey!
Your answer is CENTRIOLES
Explanation:
We know that Plants have a CELL WALL (shape), a CENTRAL VACUOLE (water storage etc) and CHLOROPLASTS (photosynthesis)
BUT Centrioles don't form parts of the "components" of the plant cell...
I HOPE THIS HELPED YOU!Choose all the answers that apply.
The cell wall _____.
A.) is thick and rigid
B.) is made of cellulose
C.) does not allow the transport of chemicals
D.) is only present in animal cells
E.) supports and protects the cell
Answer:
The cell wall is thick and rigid, made of cellulose, and supports and protects the cell.
A population of frogs in a pond began with 67 individuals. Over one year, the population changed to 53.
Which are two possible reasons for the change within the frog population?
emigration or increase in death rate
emigration or increase in birth rate
immigration or decrease in death rate
immigration or increase in birth rate
PLZ HURRYYYY 20 POINTS
Answer:
A. emigration or increase in death rate
Explanation:
i just took the test and got it rigt lol
The two possible reasons for the change within frog population is emigration or increase in the death rate. Thus, the correct option is A.
What factors affect the population?The major factors which affect the population of a species are birth rate, death rate, and migration of the species.
Birth rate is the number of individuals born in a population in a particular time period. Birth rate adds more individuals to a population.
Death rate is the number of individuals die in a population in a particular time period. Death rate decreases the population number.
Immigration is the number of individuals which enter a population.
Emigration is the number of individuals which migrate out of a population.
Therefore, the correct option is A.
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PLEASE HELPPP
1) Briefly describe the process of DNA replication.
a) Start with the molecular machinery and be sure to describe what DNA polymerase does. Use the terms ‘free nucleotides’, ‘helicase’, ‘polymerase’, ‘complementary’.
b) describe the result; how many strands were made? Describe their composition. Use the terms ‘parental DNA’ and ‘new DNA’.
Answer:
The biological process that involves produces two exact copies of DNA from a DNA molecule is called DNA replication.
In this process, the enzyme helicase unzips the DNA double helix by breaking the hydrogen bonds that bind bases together in the structure. Unzipping the hydrogen creates a replication fork. Every strand of the DNA acts as a template but oppositely oriented known as the leading strand in 3’ to 5’ direction and the lagging strand in the 5’ to 3’ direction.
One of the strands is oriented in the 3’ to 5’ direction (towards the replication fork), this is the leading strand. The other strand is oriented in the 5’ to 3’ direction (away from the replication fork), this is the lagging strand. As a result of their different orientations, the two strands are replicated differently.
Primer acts as an initiating site for DNA synthesis and DNA polymerase enzyme adds new complementary nucleotide base by attached and moving on the leading strand in the direction of 5' to 3' which is reversed to the strand.
After the binding and synthesis of all the bases, the enzyme called exonuclease removes the primer from the strand. One new and an old chain of two DNA molecules are synthesized by DNA replication due to the one new and one parent molecule in DNA it is known as semi-conservative.
Carrie is conducting an experiment on a solution. The solution’s initial pH is 10. Then, as Carrie gradually adds Compound X into the solution, the pH decreases to 5. Which is the most likely identity of Compound X? *
Answer:
Compound X must be an acid
Explanation:
Acids have a lower pH than alkaline solutions. When you add an acid to a solution, the pH drops, as has happened here. If the pH did not change, we would assume compound X was neutral. If the pH increased, we would assume compound X was even more alkaline than pH 10.
Which of the following processes allows the cells of an
organism to use carbon from the environment?
A mitosis
B fertilization
C transpiration
D photosynthesis
Why are ion channels necessary to transport ions into or out of a cell?
Answer:
Ions carry electric charges and are not soluble in the lipid bilayer of the cell membrane.
Explanation:
I found it on google lol
Ions are too large molecules to diffuse through the cell membrane hence require some proteins to facilitate their transport. Ions channels helps in transporting the ions through the cell membrane and the flow of current through the membrane.
What are ion channels?
Ion channels are the type of transport proteins which are present in the cell membrane that facilitates the movement of ions through the membrane. Cell membrane is selectively permeable in nature and thus does not allow many molecules to transport through it.
Ion channels facilitates the passive movement of ions across the cell membrane and are essential for cell survival. Ion-channels helps in elucidating the structure-function mechanisms of the proteins present in the membrane. Ion channels help in creating ion gradient and moving charge through the membrane.
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What type of mutation would result (nonsense, missense, silent,
Frame-Shift)
Answer:
Nonsense missense silent
During the action of a sodium-potassium pump, 50 ATP molecules were spent. Predict how many sodium ions are transported across the cell membrane. A. 50 B. 100 C. 150 D. 200
Answer:
150
Explanation:
each atp moves 3 Na+ and 2 K+ molecules
Fats,waxes, oils and steroids are all examples of which macromolecule
Answer:
Fats, waxes, oils and steroids are all examples of macromolecule " lipids "
isolation occurs when two species occupy different habitats within the same geographical range.
Question:
_____ isolation occurs when two species occupy different habitats within the same geographical range.
Answer:
Habitat
Explanation:
Habitat isolation occurs when individuals in two populations are separated geographically. For example by a river or a mountain range. These organisms are much less likely to interact with each other and attempt to reproduce.
Habitat isolation is a barrier to gene flow (mixing of genes in two populations) and is a mechanism of speciation.
13. Galapagos finches are birds that live on islands
off the coast of South America. The finches on the
various islands are very different from each other.
As a result of the different food resources on the
islands, which of the following structures of the
Galapagos finches experienced the greatest
change through natural selection?
(5 Points)
Head size
Eye shape
Feather color
Beak shape
Galapagos finches experienced the greatest change through natural selection in the beak shape. The correct option is D.
What is natural selection?Natural selection is the variation in individual survival and procreation brought on by phenotypic variances.
The evolution of a population's heritable features across generations is a fundamental mechanism of evolution.
Short beaks of Darwin's finches proved to be an adaptation that rendered them better adapted to grub-eating and poking holes in the ground.
However, Darwin's theory of natural selection was strengthened by Galapagos finches.
Until they all split off to become separate species, Darwin's Finches' advantageous characteristics were chosen for over many generations. These birds possessed distinct beaks, although being almost identical to mainland finches in all other respects.
Thus, the correct option is D.
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Which of the following correctly differentiates between the science in the time of Aristotle and science in the time of Galileo?
a) In Galileo's time, science was more like philosophy, whereas in Aristotle's time, it involved objective, empirical test.
b) In Aristotle's time, science was more like philosophy, whereas in Galileo's time, it involved objective, empirical test.
c) In Galileo's time, science was practiced only by great thinkers, whereas in Aristotle's time, it could be practiced by anyone.
d) In Aristotle's time, science was practiced only by great thinkers, whereas in Galileo's time, it could be practiced by anyone.
Answer:
the answer is b i believe:)
Explanation:
hope this helps love:))