Answer:
Oxygen makes up about one-fifth the volume of Earth's atmosphere today, and is a central element of life as we know it.
But that wasn't always the case. Oxygen, although always present in compounds in Earth's interior, atmosphere, and oceans, did not begin to accumulate in the atmosphere as oxygen gas (O2) until well into the planet's history. What the atmosphere was like prior to oxygen's rise is a puzzle that Earth scientists have only begun to piece together.
Earth coalesced a little more than 4.5 billion years ago from bits of cosmic debris. Liquid oceans existed on the planet almost from the beginning, although in all likelihood they were repeatedly vaporized by the massive meteorites that regularly clobbered the planet during its first 700 million years of existence. Things had settled down by 3.8 billion years ago, when the first rocks that formed under water appear in the geologic record. (They exist in what is now southwest Greenland.)
If Earth had water, it must have had an atmosphere, and if it had an atmosphere, it must have had a climate. What was Earth's early atmosphere made of? Nitrogen (N2), certainly. Nitrogen makes up the bulk of today's atmosphere and likely has been around since the beginning. Water vapor (H2O), probably from volcanic emissions. Carbon dioxide (CO2), also emitted by volcanic eruptions, which were plentiful at that time. And methane (CH4), generated inside the Earth and possibly also by methane-producing microbes that thrived on and in the seafloor, as they do today.
Carbon dioxide, water vapor, and methane played an important role in Earth's subsequent development. Four billion years ago, the Sun was 30 percent dimmer, and therefore colder, than it is today. Under such conditions, Earth's water should have been frozen, yet clearly it wasn't. The water vapor, carbon dioxide, and methane acted as greenhouse gases, trapping heat and insulating the early Earth during a critical period in its development.
Of oxygen, meanwhile, the early atmosphere held barely a trace. What did exist likely formed when solar radiation split airborne molecules of water (H2O) into hydrogen (H2) and oxygen (O2). Hydrogen, a lightweight gas, would have risen above the atmosphere and slowly been lost to space. The heavier oxygen gas, left behind, would have quickly reacted with atmospheric gases such as methane or with minerals on Earth's surface and been drawn out of the atmosphere and back into the crust and mantle. Oxygen could only begin to accumulate in the atmosphere if it was being produced faster than it was being removed'—in other words, if something else was also producing it.
That something was life. Although the fossil evidence is sketchy, methane-producing microbes may have inhabited Earth as long ago as 3.8 billion years. By 2.7 billion years ago, a new kind of life had established itself: photosynthetic microbes called cyanobacteria, which were capable of using the Sun's energy to convert carbon dioxide and water into food with oxygen gas as a waste product. They lived in shallow seas, protected from full exposure to the Sun's harmful radiation. (To learn more about these organisms and the fossil evidence for them, watch the accompanying video "Early Fossil Life.")
Human blood's pH is 7.4. What kind of drinks are safe for us.
*
Highly Acidic
Neutral or close to neutral
O Highly Basic
pH O, PH1, PH13, and pH14
What is the function of the macromolecule nucleotide?
A.SHRED STC
B.Immediate energy
C.Stored enery
D.Body instructions
Answer:
I believe that the answer is D.
Explanation:
A) is wrong
B) is carbohydrates
C) is lipids
D) is nucleic acids and the monomer of nucleic acids are nucleotides.
Please I need the the experimental group, the control group, independent variable, dependent variable and controlled variable and a summarized version of the experiment by today please!
“Chad is attempting to determine how different colors of light
affect plant growth. Chad places one spider plant in a cabinet
under a blue light and one spider plant in a cabinet under a red
light. Chad knows he needs to compare his plants to a plant
grown under white light so he places a third spider plant on the
window sill where the sun shines. All plants are the same age
and are given equal amounts of light time, plant food and water.
At the end of a two week period, Chad will measure the height of
each plant.”
Answer:
can you please answer my question please
Explanation:
pleaseee
Please help me ASAP real quick n easy
Answer:
Carbon monoxide gas.
Explanation:
The others are direct sources of groundwater pollution as the go directly on the ground. Hope this helps!
Viruses are one of the leading causes of illness in the world
True
False
Answer:
True
Explanation:
Answer:
False, but be sure you read what follows.
Explanation:
False: Heart disease and Most Cancers are not viruses. Or at least as far as I know. However complicating the issue is the fact that after a viral infection, heart disease can develop.
Cancer is another example, and the answer again is not black and white. 16% of all cancers can trace their beginnings to a bacteria or virus. That leaves 84% whose beginnings are not that clear.
The question is not black and white. I'd be careful how you think of it. If something is a complication, is that a direct cause? I still think the answer is false, but don't be surprised if your instructor disagrees. Move on to something a little less black and white.
What holds amino acid chains within a protein in shape?
Answer:
Proteins are the end products of the decoding process that starts with the information in cellular DNA. As workhorses of the cell, proteins compose structural and motor elements in the cell, and they serve as the catalysts for virtually every biochemical reaction that occurs in living things. This incredible array of functions derives from a startlingly simple code that specifies a hugely diverse set of structures.
In fact, each gene in cellular DNA contains the code for a unique protein structure. Not only are these proteins assembled with different amino acid sequences, but they also are held together by different bonds and folded into a variety of three-dimensional structures. The folded shape, or conformation, depends directly on the linear amino acid sequence of the protein.
Explanation:
Viruses exist on a microscopic scale
True
False
Answer:
True
Taking a look at viruses under the microscope. Unlike other unicellular organisms like bacteria, viruses are commonly referred to as particles rather than cells.
Light energy for the plant to use in making its food is trapped during ____ reactions.
a.
light-independent
c.
light-dependent
b.
glucose-dependent
d.
oxygen-dependent
Answer: c. light-dependent
Hope this helps!!! :)
Answer:
The answer is C. light-dependent
Explanation:
Edge 2021 + top comment !
An agricultural biologist was evaluating two newly developed varieties of wheat as potential crops. In an experiment, seedlings were germinated on moist paper towels at 20ºC for 48 hours. Oxygen consumption of the two-day-old seedlings was measured at different temperatures. The data are shown in the graph below. In a second experiment, variety A seedlings at both temperatures were treated with a chemical that prevents NADH from being oxidized to NAD+. Predict the most likely effect of the chemical on metabolism and oxygen consumption of the treated seedlings. Explain your prediction.
Answer:
The definition is listed in the clarification segment below, and according to the present circumstances.
Explanation:
It undergoes different morphological as well as biochemical modifications mostly during germination. Product contains nutrients and even some hydrolases such as energy, carbohydrates. Owing to the availability of phytic compounds, the seed coat seems to be very durable in nature. Hydrolytic enzymes launch their function by consuming oxygen throughout order to remove this hard coating. In several other processes, including the electron transport system as well as the Kreb process, oxygen also becomes necessary.
The initial phase of germinating seeds requires anaerobic environments where even the enzymes dehydrogenase can function. The subsequent dehydrogenase enzyme brings the electron throughout the electron transport system from either the base to oxygen. Unless the oxygen frequency is compared with varieties A and B, it can be seen through the analysis that variety B actually absorbed more oxygen. Oxygen intake rates are also depending upon period.The impact of temperature mostly on absorption of oxygen seems to be present. Shift the supply at low temperatures have a low intake of oxygen, while varieties grown over extreme temperatures use much more oxygen. The metabolism of such a seedling is influenced by temperature. Metabolically active young plants display a larger intake of oxygen.The mother has long fur:
(FF)
F= long fur
The father does not have long fur:
(ff)
f=short fur
Answer:
are you looking for a pedigree, or a square pedigree?
Explanation:
What type of substance do humans make?
Answer:
Almost 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium. All 11 are necessary for life.
Explanation:
Brainliest; please?
Which of the four prokaryotes listed below is the most efficient?
A. facultative aerobes
B. obligate anaerobes
C. aerotolerant organisms
D. obligate aerobes
Answer:
B
Explanation:
Which of the following is not an example of energy transformations in an ecosystem? a. sunlight driving photosynthesis in plants b. herbivores feeding on plants c. predators feeding on herbivores d. none of the above Please select the best answer from the choices provided A B C D
Answer:
D. None of the above
Explanation:
Energy transformation is the process of transfer and conversion of energy from one species to another. None of the above is not an example of energy transformation. Thus, option D is correct.
What is energy transformation?Energy transformation is the process in an ecosystem that includes the conversion of energy from one level to another in the food chain or the metabolic reactions.
Photosynthetic reactions under the sun, herbivores feeding on producers, and predators feeding on the primary consumers are examples of energy conversion as it is continuously passing the energy to another species in the ecosystem.
Therefore, none of the above is not an example of energy transformation.
Learn more about energy transformation here:
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Choose the answer that best describes the order of the life cycle of a large star.
•gas clouds, star ignites, hydrogen depleted, red supergiant, super nova, neutron star
•gas clouds, star ignites, neutron star, hydrogen depleted, red giant supernova
•gas clouds, nuclear reaction, hydrogen depleted, red giant white dwarf
Answer:
I think its A gas clouds, star ignites, hydrogen depleted, red super giant, super nova, neutron star
Explanation:
Its Not gas clouds, nuclear reaction, hydrogen depleted, red giant white dwarf that is the wrong answer
How do vaccinations work to provide immunity? and What body system regulates blood glucose levels? (For a Biology exam)
Thanks :)
Answer:
it trains the body immunity towards certain diseases
Explanation:
first of all we humans have two types of wbc cells phagocytes & lymphocytes. phagocytes produces pseudopodia which is like cytoplasm that traps or catches bacteria or viruses. lymphocytes produces chemical antibodies which destroy the viruses or bacteria by attaching to the virus and burst it out. Now when u get vaccinated u train those wbc cells for future viruses and hepl them to make antibodies to defend the body.
The blood glucose gets regulated by production of insulin in pancreas to maintain proper amount of glucose in the body
please help.
what happens to a monomer once it is used to create a polymer?
A. the monomer can be reused once the polymer is deconstructed
B. the monomer is destroyed
C. The monomer is permanently part of the polymer
The monomer can be reused once the polymer is deconstructed. So, the correct option is (A).
What is Monomer?A monomer is defined as a molecule which can react with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization.
These are described as atoms or small molecules which bond together to form more complex structures known as polymers. There are four main types of monomer which include sugars, amino acids, fatty acids, and nucleotides.
Monomers can also be reused again when the polymer is deconstructed.
Thus, the monomer can be reused once the polymer is deconstructed. So, the correct option is (A).
Learn more about Monomers, here:
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how do the respiratory and circulatory systems work together to maintain homeostasis
Explain at least three ways in which a mutation in an individual's DNA could occur, and describe at least 2 effects a mutation could have on an individual's traits.
Answer:
Explanation:
Three ways in which mutation could occur are
1) If an error occurs during DNA replication and it's not corrected in time by DNA polymerase.
2) If there is a deletion of a base(s) in the sequence of the DNA. The deletion of a DNA nucleotide/base could also cause a mutation as that could affect the formation of an enzyme or protein useful in building and/processing certain body parts/processes.
3) Thymine dimerization: Thymine dimers are mutations that prevent DNA from replication or even transcription hence preventing a cell from undergoing division (hence causes cancer). They are formed when covalent bonds are formed between the bases of a DNA sequence (somewhere around the carbon-carbon double bond).
The two effects are
1) It could cause cancer as described in (3) above (in the case of thymine dimer)
2) It could lead to deformity in an individual because of the gene that is supposed to code for the last finger has a base deletion, that could eventually lead to the absence of that finger or a shorter or "strange" finger.
How does oxygen enter the cells of the tube worm
Answer:
Flatworms are small, literally flat worms, which 'breathe' through diffusion across the outer membrane (Figure 2). The flat shape of these organisms increases the surface area for diffusion, ensuring that each cell within the body is close to the outer membrane surface and has access to oxygen.
Explanation:
Hope this helps!
Answer:
This is what you need
Explanation:
Flatworms are small, literally flat worms, which 'breathe' through diffusion across the outer membrane The flat shape of these organisms increases the surface area for diffusion, ensuring that each cell within the body is close to the outer membrane surface and has access to oxygen.
Which type of specialized cell is responsible for sending signals throughout the body?
Nerve cells
Epithelial Cells
Muscle Cells
Blood Cells
its multi choice
Answer:
NERVE CELL
THANKS FOR POINTS
PLS HELP ANSWER I WILL DO THE BEG
Answer:
its bbbbbbbbbbb
Explanation:
First correct answers get Brainlies. Spam answers get flagged.
New Zealand has a population of 4,326,380 and has an area of 103,736 miles squared while Australia has an area of 2,967,909 miles squared and a population of 21,905,140. Explain how New Zealand can have a larger population density than Australia even though it has a smaller total population.
The reason they have a higher population density is because they have more people on average in a certain area, because New Zealand is smaller they are given less space to live, this means that more people are crammed together, making the density of people within a square mile higher. When you give less square miles, you reduce the amount you have to divide the population by, which makes the density go up.
( In case you wanted the calculations for the density on New Zealand and Australia, it is about 41 to 42 people a square mile in Zealand, and maybe 7 or 8 per square mile in Australia.)
Hope this helps, if not, comment below please!!!
how does each of your mutations affect the amino acid sequences? Are the mutations missense mutations, silent mutations or nonsense mutations?
a. Point mutation?
b. Frameshift-insertion?
c. Frameshift-deletion?
Answer:
the correct answer is B Frame shift insertion
Explanation:
plz give me brainiest
Frameshift-insertion mutations affect the amino acid sequences.
Thus, The insertion or deletion of nucleotide bases in amounts that are not multiples of three is referred to as a frameshift mutation in a gene.
This is significant because a cell reads the genetic code for proteins in groups of three nucleotides.
These so-called "triplet codons" each stand for one of the 20 different amino acids that go into making a protein. This normal reading frame will be disrupted by a mutation, which will result in an inaccurate reading of the entire gene sequence after the mutation.
Thus, Frameshift-insertion mutations affect the amino acid sequences.
Learn more about Frameshift insertion, refer to the link:
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If you are reading this then congratulations I’m wasting your time and you could be doing school. But it’s weird since I’m constructing this sentence other then doing school your thinking that I’m a hypocrite. I am. And I wasted even more of your time is your reading the last word of this sentence.
tooru oikawa's favorite food is milk bread, and his personal motto is "if you're gonna hit it, then hit it 'till it breaks?!"
I need help on those two questions
What is the name of the structure labeled A in the diagram below?
A
F
B
D
O A. Cytoplasm
OB. Nucleus
ООО
C. Mitochondrion
O D. Ribosome
Answer:
I believe its C
Explanation:
The structure labeled A in the diagram is of mitochondria.
What is mitochondria?It is a double membranous organelle.The space between its two membranes is called intermembrane space.It is also known as powerhouse of cell as it generates ATP.Cristae is present in it.
Hence, option C. mitochondria is correct.
To know more about mitochondria here
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Earthquakes that occur far from plate boundaries are called
Answer:
intraplate' earthquakes
Explanation:
Which of the following explains why some plants look green?
Your Answer
A
chlorophyll is the main plant pigment and it absorbs mainly wavelengths of light that are
B
chlorophyll is the main plant pigment and it transmits mainly wavelengths of light that ar
chlorophyll is the only type of plant pigment found in leaves
x plants contain different pigments which absorb and transmit different wavelengths of ligi
Back
C chlorophyll is the only type of plant pigment found in leaves
Answer:
the answer is a
Explanation:
A species is a group of organisms so similar to one another that they can breed and produce fertile offspring. True or False.
Answer:
True
Explanation:
That is the exact definition that I learned.
ok this is the last one
Answer:
Compound sentence
Explanation:
it uses a conjunction to add the to sentences together.