1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
andrew11 [14]
3 years ago
13

The oxygen build-up in the atmosphere was caused by .

Biology
2 answers:
Ymorist [56]3 years ago
6 0

<em>Eukaryotic Organisms</em>

vladimir1956 [14]3 years ago
3 0
Most scientists believe that for half of Earth's 4.6-billion-year history, the atmosphere<span>contained almost no </span>oxygen. Cyanobacteria or blue-green algae became the first microbes to produce oxygen<span> by photosynthesis, perhaps as long ago as 3.5 billion years ago and certainly by 2.7 billion years ago.
this answer came from this website </span>The Rise of Oxygen - Astrobiology Magazine<span>www.astrobio.net/news-exclusive/the-rise-of-oxygen/
it should help</span>
You might be interested in
Please help !!!<br> A) facultative<br> B) mutualistic <br> C) parasitic <br> D) obligate
laiz [17]

The answer is mutualistic

3 0
3 years ago
Place the following events in the proper order. 1) Activation of one or more cellular signaling proteins. 2) Dissociation of Ga
dolphi86 [110]

Answer:

4) Replacement of GDP by GTP on the Ga after interaction with an activated GPCR.

5) Conformational change in the Ga subunit causing a decreased affinity for the Gb g subunit.

2) Dissociation of Ga from the G protein complex.  

6) Ga-subunit with its attached GTP activates an effector like adenylyl cyclase.

3) Production of a second messenger, like cAMP.    

1) Activation of one or more cellular signaling proteins.

Explanation:

It is a signaling cascade initiated by G proteins. These G proteins function as molecular switches capable of activating signaling pathways in the presence of guanosine triphosphate (GTP), which is hydrolyzed in order to produce energy

6 0
3 years ago
Which of the following statements about kinetic energy is incorrect
Alona [7]
To do the top of stored energy.
6 0
3 years ago
There has been much controversy on immunizing children • (vaccinating them), especially in regards to autism. This has led to th
4vir4ik [10]

Answer:

i dont know the work week

8 0
2 years ago
Read 2 more answers
What is energy in a system
sammy [17]
Energy in a system is doing work such as kinetic and potential energy, that helps things move. Also more such as chemical, heat, thermal, etc.
7 0
3 years ago
Other questions:
  • Which of these is the BEST way to illustrate the percentage of students receiving A's, B's, C's, D's and F's on a recent test?
    15·1 answer
  • In the Northern Hemisphere, south-facing mountain slopes form a microclimate, because they are _______.
    9·2 answers
  • Which amino acid chain would be produced by the dna base sequence below?
    12·1 answer
  • Why are there so many different species of honeycreeper living on the Hawaiian Islands?
    5·1 answer
  • 1. A polymer is comprised of repeating monomers that are connected to each other through dehydration synthesis reactions. What a
    5·1 answer
  • The clearing of forests for construction and the pollution of ecosystems are both examples of
    8·1 answer
  • What is layer E pointing to
    7·1 answer
  • A cell is placed in an isotonic solution. How does the cell maintain homeostasis in this environment?
    14·1 answer
  • Your little brother picks all the chocolate out of the trail mix before you can fix a baggie for your hike . How was he able to
    12·1 answer
  • Spider silk is a material made of proteins that has a strength per gram that is five times that of steel. One feature of some of
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!