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
Furkat [3]
4 years ago
9

Which of the following gases was not believed to be present on Earth at the time of its formation 4.6 billion years ago? a. oxyg

en c. water vapor b. nitrogen d. methane
Biology
2 answers:
Ilya [14]4 years ago
7 0
A. Oxygen
I believe that's the answer
igomit [66]4 years ago
7 0

Answer:

a. oxygen

Explanation:

If you could build a time machine and go back to Earth's distant past, you would have an unpleasant surprise: you wouldn't be able to breathe. Without the help of equipment, you would suffocate in a matter of minutes.

That's because during the first half of our planet's life there was no oxygen in the atmosphere. The gas so fundamental to life as we know it came about only 2.4 billion years ago.

The "Great Oxidation Event" was one of the most important things to happen on this planet. Without it, there could never be animals breathing oxygen, such as insects, fish and certainly humans.

You might be interested in
Why is double strength medium used in inoculation of 10 ml portion?
Amiraneli [1.4K]

Answer:

3

Explanation:

Infrared, is much more different compared to Bluetooth and WiFi. Infrared uses, as the name infers… the infrared spectrum of light. It is basically red light which is not visible to our human eyes. Unlike radio waves, infrared cannot pass through walls and other obstructions, so the applications are usually limited to devices that are within Line-Of-Sight or where light can travel

3 0
2 years ago
If an electric charge is shaken up and down
Nookie1986 [14]
<span>If an electric charge is shaken up and down "A Magnetic field is created"

In short, Your Answer would be Option D

Hope this helps!</span>
8 0
4 years ago
Read 2 more answers
In order to explain DNA's consistent width, Watson and Crick concluded that
Kipish [7]
The answer is C. Purines (A and G) have double-ring structure while pyrimidines (C and T) have single rings. The obligate complimentary base pairing between a purine and pyrimidine ensures that the width between the helix backbones are maintained at approximately 20 angstroms.
5 0
3 years ago
Read 2 more answers
what process best explains how a nerve cell and a muscle cell can both develop from the same fertilized egg
Galina-37 [17]

Differentiation is the best process basically.

5 0
3 years ago
What is wrong with the food chain that was drawn? <br> Plant → Animal → Animal → Plant
7nadin3 [17]

plants cant eat animals some plants can eat bugs not animals

6 0
3 years ago
Read 2 more answers
Other questions:
  • What happens to the chitin exoskeleton of an arthropod as the animal gets larger?
    12·1 answer
  • Explain how endocytosis, digestive enzymes and exocytosis work together to get rid of bacteria
    12·1 answer
  • The process by which a final product acts as an inhibitor to the enzyme that catalyzes the commitment step in a metabolic pathwa
    12·1 answer
  • Superantigens are substances that trigger an inappropriate and nonspecific activation of the immune system. Rather than triggeri
    8·1 answer
  • Which type of biomass energy is produced from vegetable oils and animal fats? A. ethanol B. methane C. biodiesel D. wood fuels
    9·2 answers
  • Help me please!!!!!!!!
    11·1 answer
  • In mammalian eggs, the receptors for sperm are found in the A) fertilization membrane. B) zona pellucida. C) cytosol of the egg.
    11·1 answer
  • WHICH ONE IS IT??? AHHH
    10·2 answers
  • 13. On a compound microscope, the power that is best for viewing cell organelles is the
    12·1 answer
  • 2. Which type(s) of cells have genetic material that is contained in a nucleus?
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!