Which event was a major source of atmospheric oxygen?

photosynthesis

volcanic eruptions

decomposition of water

outgassing

Answers

Answer 1

Answer:

Photosynthesis was a major source of atmospheric oxygen.

Explanation:

Earth's atmosphere was not the same as it is in the past. For a larger portion of Earth's history, the atmosphere actually didn't have an atmosphere or the one it had was not suitable for complex lifeforms to develop. This all changed because of one major event, the process of photosynthesis.

Initially, it was the cyanobacteria that started to use this process in order to produce their own food and energy. Basically, this process meant that the cyanobacteria, and a lot of later organisms, were taking in carbon dioxide, use it for their own needs, and release the oxygen. The oxygen was released into the ocean and into the atmosphere, which resulted in a gradual change in the composition of the atmosphere to a degree where it was suitable for larger organisms to start to develop.


Related Questions

Who was the first person to ever walk the Earth?

Answers

Answer:

Adam(Biblical), No one knows(Logic)

Explanation:

If you're looking for a Biblical answer, the answer will be Adam. If you're looking for more of a Logical answer, the answer is...no one knows.

How is it possible for the sun to be more luminous than a white dwarf if the sun has lower temperature

Answers

A white dwarf may be hot but it is not generating energy, it is losing it.

A white dwarf is the remains of a star after fusion reactions have finished. The core collapse which creates a white dwarf makes it initially very hot. It can be over
100
,
000
K
.
White dwarfs emit radiation while they cool down over a very long time period. They are very small and have very low luminosity.
A star like the Sun on the other hand is constantly producing energy from fusion reactions in the core. Although the surface temperature may only be
6
,
000
K
, the core is at
14
,
000
,
000
K
and constantly producing energy. Hence the Sun is much larger and much more luminous.
Red giant stars are even cooler at less than
4
,
000
K
. They still have fusion reactions taking place in or around the core. They are very large and very much more luminous than the Sun.

Compare the natural conditions for the development of agriculture in Denmark and Hungary.​

Answers

I’m not sure. What story is that?

The United States’ economy produces 20% of the world’s __________. A. input B. wealth C. output D. resources

Answers

Answer:

Output

Explanation:

Answer:

C. output

Explanation:

What are two different ways you could find the value of a? Explain these methods.

A right triangle is shown. An altitude is drawn from the right angle to the opposite side to form 2 line segments with lengths 9 and 16. The length of the other 2 sides are 15 and a.

Answers

Answer:

Sample Response: You could use the Pythagorean theorem, since you know the length of the hypotenuse is 9 + 16 = 25 units and the length of one leg is 15 units. To find the value of a, use the relationship that the the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the legs. You could also use the geometric mean (leg) theorem, which states that the length of the hypotenuse is to the length of an adjacent leg as that adjacent leg length is to the length of its corresponding segment in the hypotenuse. So you could write and solve the proportion 25/a = a/6.

Explanation:

I just did it

From the triangle given, the ways to find a will be the use of a Pythagorean theorem and a geometric mean.

By using the Pythagorean theorem, one will have to add the square of the legs and find the square root. Since the hypotenuse is 9 + 16 = 25 units and the length of one leg is 15 units. Then, in order to find the value of a, one will have to use the Pythagoras theorem.

Also, one can use the geometric mean theorem. Therefore, the values given will be rewritten as 5/a = a/6. Then, the person can solve the equation.

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'Cube'ism
As an artist, Ernest is doing a solo show titled CUBES. One of his pieces is
shown below. Each layer of the piece is a cube. The bottom cube has a side
length of 3 m, the middle cube has a side length of 2 m, and the top cube has a
side length of 1 m. The top two layers are each centred on the layer below.
Ernest wishes to paint the piece. Since the piece will be suspended in the air, the
bottom will also be painted. Determine the total surface area of the piece,
including the bottom.

Answers

Answer:

jj

Explanation:

Answer:

74

Explanation:

What is the measure of

Answers

Answer:

Sorry this question is invalid and not understandable

How are forest useful for us???



Please guys give answer in very short.......​

Answers

Answer:

We depend on forests for our survival, from the air we breathe to the wood we use. 

Explain why the climate of the polar regions is so cold (4 marks)

Answers

Answer:

this is because the polar regions have less sun rays sticking them compared to any other regions hence the temperature at the polar region is always low

PLS HELP IM BEING TIMED

Explain one key reason why many Europeans are willing to pay higher taxes to support a welfare state in their countries.

Answers

Answer:

The taxes are higher

Explanation:

Because we have (in Sweden) free health care for children under 18 when ur over 18 u will only pay til you have paid to a specific amount then you have discount and then its free (every year it will go back to cero)
School is free lunch in schools are free we don’t pay for anything not even textbooks.
Medication for people under 18 is free. People with low income pay little or no tax rich people pay higher taxes. Its all about balance. We don’t like to be like the US but still we have a lot of segregation. I hope my answer somehow helps

A title given to a Muslim ruler, often a prince or tribal chief, is __________. A. emir B. knesset C. sharia D. sunni Please select the best answer from the choices provided

Answers

Answer:

A. Emir

Explanation:

A title given to a Muslim ruler, often a prince or tribal chief, is Emir.

Emir refers to an individual who is saddled with leadership responsibility of protecting, controlling, managing and maintaining all of the affairs of his subjects i.e the indigenes of the town he his ruling.

Generally, emirs are found in the northern part of various countries across Africa such as Nigeria, Sudan, Niger, etc. For example, Emir of kano, Emir of bida, etc.

Answer:

Emir

Explanation:

What named the country Soviet Union?

Answers

Answer:

In post-revolutionary Russia, the Union of Soviet Socialist Republics (USSR) is established, comprising a confederation of Russia, Belorussia, Ukraine, and the Transcaucasian Federation (divided in 1936 into the Georgian, Azerbaijan, and Armenian republics).

Explanation:

Natural resources paragraph

Answers

Answer:

Paragraph on Natural Resources:

Natural resources are substances that are found naturally without any engagement from human beings. ... Natural remedies can be found in different forms. It can be found as non-living things like minerals, air, water, etc. These are called abiotic resources.Jul 22, 2020

How would human activities affect the migration of animals like the Christmas crabs in Australia?

Answers

Answer:

Most of Christmas Island's adult red crabs begin their breeding migration to the sea as soon as the wet season rains have established. But we can never be sure when the wet season is going to begin!

The crabs' breeding timetable is fixed around the phases of the moon. Spawning (the dropping of their eggs into the sea) must occur before sunrise on spring tides during the last quarter of the moon, regardless of any other factor. The timing of spawning is the only certain and predictable part of the whole migration; all other stages of the migration will vary with the prevailing weather.

The crabs will start their migration if there is enough time for them to complete their downward migration, mate and develop eggs before the next suitable spawning date.

The red crab breeding migration comprises a series of separate actions on the crabs' part that follow on from one to the other in a programmed sequence. These separate actions in combination make up the breeding migration and one action will not occur unless the preceding action is accomplished. If there isn't enough time for them to be able to do all of these things before the next spawning opportunity, they will delay the start of their migration and attempt to meet the following month's spawning date.

The first action that occurs is movement of crabs to the sea. The largest mass movement of crabs takes place in this first downward migration. Males farthest inland start this movement and are progressively joined by more and more crabs (both males and females) as the movement progresses toward the sea.

When the crabs arrive at the shoreline, they dip in the sea to replenish body moisture and salts. The male and female crabs then move back on to the shore terraces where the males dig burrows for mating. Mating takes place and then the males again dip in the sea and then they will start their return migration.

The females remain behind in the mating burrows to brood their eggs. This takes a couple of weeks. A day or two before the spawning date the females emerge from the breeding burrows with ripened eggs and move to the shoreline where they again dip in the sea and then retreat to shade.

Before the turn of the high tide and just before dawn the females will again move to the waterline and around the turn of the tide they will drop their eggs into the sea. After they have jettisoned their eggs the females commence their return migration.

The next phase of the breeding migration takes place in the sea. The eggs that the females drop into the sea hatch immediately into larvae. They grow through several larval stages into tiny prawn-like animals called megalops. After about four weeks the megalops emerge from the sea and they moult into baby crabs. The baby crabs then move inland and settle at suitable localities. The successful emergence of baby crabs is unpredictable but is incredible when large numbers emerge. Some years very few, or none, emerge. After about four years growth crabs will take part in the breeding migrations and the life cycle continues.

If the rains stop or peter out, the crabs will delay the start of their migration, or, if they have started migrating, they will stop moving and stay wherever they are until the rains begin again. It is rare that substantial rains will begin early enough in the year for a spawn during the last lunar quarter in October - but it has happened! Spawning in November or December are the more usual, which means that rain must commence in the preceding month and continue.

All phases of the crabs' breeding migration involve colossal numbers of crabs and usually occur all over the island. If the rains continue, there is usually a second, and sometimes even a third, smaller, downward migration by crabs that did not join in the first migration. When this happens it is possible to see crabs on return journeys mingling with the crabs on their downward migration. It can become confusing for all concerned! We are sorry that we can not be more explicit about the timing of the start of the red crab migrations, but the weather as you know cannot be accurately predicted. The best advice we can give is to be at Christmas Island during the last quarter of the moon in either November or December for the best chance of seeing something interesting happening in the annual red crab migration. If you are able to arrive earlier and to stay longer the more parts of the migration sequence you will be able to experience.

Explanation:

1. What do you call two tectonic plates that are moving away from each other?
2. Two tectonic plates moving toward each other?
3. Two plates that are moving toward each other and one plate slides under neath the other?
4. Two plates that are moving in opposite directions and their boundaries are scraping past each other? ​

Answers

The answer is the last one
1. Divergent
The plates that move apart are called diverging plates. As the diverging plates move apart, a crack is created that causes magma to rush up and form a new bedrock. Most are found on the seabed.

2. Convergent
The plates that move towards each other, ie the plates that eventually collide

3. Subduction zone
It is a boundary area in the lithosphere. Two plates in the lithosphere collide with each other, as one plate is pressed down under the other and sinks into the mantle.

4. Spreading zone
Is a plate tectonic boundary where two tectonic plates move apart. The material contained in the mantle rises towards the lithosphere and this occurs at the same time as the crust cracks. When the crust cracks, magmatic mantle material rushes out between the plates.

All of this is from my own personal documents so be free to use it and dont think about plagiarism:)


Which part of the South American continent is suitable for the
practice of agriculture? Why?

Answers

Brazil

Explanation:

They have abundant land and a significant labour force

Meanders are found in the upper course of a river. True or false

Answers

Answer:

False they are usually found at the lower course of a river

Explanation:

What are 5 ways that Canada’s
landforms affect population?

Answers

People are also affected by landforms. People generally settle in flat, fertile valleys and plains, where they can build homes and crops easily. Fewer people live in mountains, swamps or desert areas.
BRAINLIEST PLEASE! ❤️

On a piece of paper, graph y< -2/5x + 1. Then determine which answer choice
matches the graph you drew.
A
B
D
(-5,3)
(-5,3)
(0, 1)
(-5,3)
(0, 1)
(-5,3)
(0, 1)
(0, 1)
-5
A. Graph A
B. Graph B
C. Graph C
D. Graph D

Answers

The graph D is matched by graph y -2/5x + 1. Option (D) is right as a result.

What does a graph mean?

A graph shows the correlation between two variables that are typically assessed along one axis of a pair at right angles.

A graph in discrete mathematics is made up of vertices a group of point and edges the lines bridging those vertices.

There are many different kinds of graphs, including connected and unconnected graphs, weighted graphs, bipartite graphs, directed and undirected graphs, and simple graphs.

Because they make information accessible and simple to comprehend, graphs and charts are effective visual aides.

Graphs are therefore often used in print and electronic media, which is not surprising. Sometimes, data can be better understood when it is presented as a chart.

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Which region was under the control of the Soviet Union?
A. Central Europe
B. Eastern Europe
C. The Nordic countries
D. Western Europe​

Answers

Answer:

Eastern europe

Explanation:

i dont understand this at all- ​

Answers

Answer:

Mee también hermano, esto es tanto que ni siquiera puedo leerlo

HELP ASAP PLEASE, WILL GIVE BRAINLIEST AND MORE!
Question 1(Multiple Choice Worth 4 points)
(05.03)Calculate the area of the regular pentagon below:

A regular pentagon with side length of 11.8 inches and dotted line from center to middle of side of 8.1 inches.

164.025 square inches
238.95 square inches
351.78 square inches
477.9 square inches
Question 2(Multiple Choice Worth 4 points)
(05.03)On a bicycle trail, the city is painting arrows like the one shown below:

Upper pointing arrow with height of 15 and length of 13. Rectangular base of arrow has length of 11 and height of 12. All units are in centimeters.

Calculate the area of the arrow by decomposing it into rectangles and triangles.

148.5 square centimeters
151.5 square centimeters
171 square centimeters
195 square centimeters
Question 3 (Fill-In-The-Blank Worth 4 points)
(05.03)Calculate the area of the figure below using the following information:

Area of triangle ABC = 7.95 square units

Area of triangle ACD = 9.8 square units

Area of triangle AED = 8.75 square units

Image of irregular pentagon with vertices points A, B, C, D, and E starting at upper left moving clockwise. Two dotted diagonal lines, one connecting vertices A and C, and the second connecting vertices A and D.

The area of the Figure ABCDE is ______ square units.

Answer for Blank 1:

Question 4(Multiple Choice Worth 4 points)
(05.03)Calculate the area of the irregular polygon shown below:

Image of letter E with height of 10 and width of 5 and inside space of height of 3 and width of 4. All units are in inches.

21 square inches
22 square inches
26 square inches
29 square inches
Question 5 (Fill-In-The-Blank Worth 4 points)
(05.03)An irregular polygon is shown below:

Image of irregular polygon with length of 9 units and height of 4 units labeled on left side. Top side length of 4 units, the side adjacent to it on the right is 2 units.

The area of the irregular polygon is ____ square units.

Numerical Answers Expected!

Answer for Blank 1:

Answers

Answer:

1). 238.95 (2nd one)

2). 151.5 (2nd one)

3).  106.5

4). 26 (3rd one)

5). 20

Explanation:

Not 100% sure, some of these I got online, others I didn't.

What impact does globalization have on the spread of languages?
it makes some local languages extinct.
it results in new vocabulary words being added to the english language.
it reduces differences in regional dialects.
new creoles of english and local languages will form
1 only
1 and 3
3 and 4
1,2 and 4
2,3 and 4

Answers

The answer is 1,2 and 4

Predict the consequences that might occur if underground aquafers run out of water?

Answers

Answer:

Consequences of this would be lack of water in the area, earthquakes, and crumbling of surface crust, and creation of huge openings in it.

Explanation:

Aquifers are basically underground reservoirs of water. They can be found at different depths and their size varies greatly. Humans have their potential and started to use them, and it has been of great benefit. The problem is that the aquifers are often overexploited, meaning that more water is extracted from them than what they gain, so their water levels drop and eventually will dry out.

By drying out, the lack of aquifers, especially in regions where freshwater is rare, will cause huge problems. People will not have enough water for their needs, and agriculture will not be possible. The crust will destabilize, and as it adjusts there will be earthquakes. The crust that has been above the aquifer will crumble because of the empty space below it and the influence of gravity, meaning that huge openings will get created, and if there is any infrastructure in the area it will get fully destroyer.

What major event in world history led to a massive global population explosion

Answers

Answer:

Industrialization and other developments led to death rates falling, while birth rates remained high. Until birth rates also fell about a century later, the population grew rapidly and population size exploded. The same demographic transition occurred a little later in other industrialized countries

Answer:

Post-Industrial Revolution

The Industrial Revolution brought innovations to food and medicine, and kickstarted an era that would be usher in the birth of many new technologies. This screenshot is from close to 1900, when these innovations started to make rapid global population growth a reality.

Explanation:

I hope it helps!

HUGSSSS

In what ocean is the plate boundary below occurring?

Answers

Answer:

what are the options

Evaluate the different approaches used to manage the threats facing deciduous woodlands in a named region.

Answers

Traditional management techniques include pollarding . This technique encourages new growth, and maintains the trees for future generations. It is a form of sustainable management in the woodland. Pollarding also encourages birds to nest.

What was the cause of food and other items being put into the tombs?

Answers

Answer:

Hi !

Here is your answer !

The wall paintings portraying scenes from daily life show how the food was consumed, at least among the wealthier classes. Bread and beer were staples in ancient Egypt and they are also the products most frequently found in the tombs.

(Sorry no explanation in this question)

Thank You !

Which statement accurately describes plate tectonics?

Pieces of the lithosphere move quickly and constantly.
The motion of subduction drives plate movement.
When one plates slides under another, it is called a convection current.
The lithosphere is broken into sections called plates.

Answers

Answer: the lithosphere is broken into sections called plates, there are 2 main types of plates: continental and oceanic

Answer:

the lithosphere is broken into sections called plates, there are 2 main types of plates: continental and oceanic

Explanation:

Which is a major reason that Central Asia has been conquered repeatedly?
A. The flat terrain made it vulnerable to attack.
B. Portugal and Spain wanted control of the Silk Road.
C. China and Australia battled for control of its resources.
D. The climate there made nomadic lifestyles impossible.
ITS A!​

Answers

Answer:

so you jus answered your own question?

Explanation:

The flat terrain made it vulnerable to attack.

Why was Central Asia conquered often?

Periodically, tribal leaders or changing conditions would cause several tribes to organize themselves into a single military force, which would then often launch campaigns of conquest, especially into more 'civilized' areas.

What is the history of Central Asia?

The human occupation of Central Asia dates back to the late Pleistocene Epoch, approximately 25,000 to 35,000 years ago, but the first identifiable human groups to live there were the Cimmerians and Scythians (1st-millennium BCE) in the west and the Hsiung-nu people (from 200 BCE) in the east.

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