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]
3 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]3 years ago
7 0
A. Oxygen
I believe that's the answer
igomit [66]3 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
A certain sea slug, Elysia chlorotica, "steals" chloroplasts from algae it normally feeds upon, and then uses the chloroplasts t
FrozenT [24]

Answer:

Horizontal gene transfer

Explanation:

Horizontal gene transfer or lateral gene transfer is when an organisms of different species can acquire a gene from a different one. This process is well understood in bacteria and is responsible for the appearence of antibiotic resistant bacteria. Bacteria can take DNA fragments through a process known as transformation, but this is less common in eukaryotes. Gene transfer agents like viruses could carry the gene from one specimen to the other. Another way could be Horizontal transposon transfer but the exact mechanisms behind it are still under research.

7 0
3 years ago
The process occurring at the sensory receptors that converts physical energy into coded neural activity that the nervous system
Anika [276]

Answer:

Sensory transduction

Explanation:

The sensory process involves many steps to send the signals from the receptor to the brain.

In this, the step that is involved in the conversion of the physical energy into the electrical signal at the sensory receptor  (in the given case mechanoreceptors) is known as the Sensory transduction.

When the mechanoreceptors get stimulus by the physical force, it opens the mechanical gate of the dendrites which allows the influx of the positive ions. The influx of the positive ions causes depolarization of the membrane which initiates the action potential which is then transmitted to the brain.

Thus,  Sensory transduction is the correct answer.

6 0
3 years ago
Read 2 more answers
Why are endemic organisms in greater danger of becoming extinct?
Liula [17]

Answer:

They are the species which are found only in a particular area. They can be a plant, animal or microorganism. They are at great danger of becoming extinct due to the following reasons: - As they are restricted to a particular area so loss of their habitat is the major reason which could lead to extinction.

Explanation:

5 0
3 years ago
Choose all the answers that apply.
Dmitrij [34]
Time of day, Wind Patterns, and Weather
3 0
2 years ago
Read 2 more answers
Which of the following is a true statement about lava that contains large amounts of dissolved gases? Lava that produces violent
anygoal [31]

<u>Answer:</u>

<em>The dissolved gases produce violent eruption as they escape. </em>

<u>Explanation:</u>

Magma contains dissolved gases and these dissolved gases induce vapor <em>pressure on the magma.</em> The magma is able to remain in the dissolved state itself without erupting because this vapor pressure is less than the confining pressure of the <em>rock surrounding the magma. </em>

One the vapor pressure exceeds this confining pressure the dissolved gases begin to  expand and<em> forms small gas bubbles</em>.

The <em>density of these gas bubbles</em> called vesicles is less than the density of magma and thus naturally tries to push out. When the gas bubbles escape the magma is also pushed out. Thus greater <em>amount of dissolved gases result in violent eruptions. </em>

"

8 0
3 years ago
Other questions:
  • Why are most of the stomata on the bottom of the leaf
    10·1 answer
  • As materials move higher to lower concentration what is occurring
    9·1 answer
  • What is the role of sensory neurons in the breakdown of food?
    15·2 answers
  • What are two ways bacteria and protists can be helpful to people?
    13·1 answer
  • A) Chromosome B) DNA nucleotide C) Codon D) Gene
    13·2 answers
  • QUESTION 1
    6·1 answer
  • in a forest ecosystem, which is an abiotic factor? (A) the amount of rainfall (B) the size of the deer (C) the type of trees (D)
    6·1 answer
  • which of the following is an example of commensalism? i just need someone to check my answer if its wrong correct me.
    15·2 answers
  • Please help<br> question is in photo
    7·1 answer
  • Consider the relevance, significance, advantages and disadvantages, and strengths and weaknesses of having a cell-mediated and a
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!