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
(b) Identify the dependent variable in the experiments. Identify a control group missing from the second experiment. Justify the
hammer [34]

Hello. You have not submitted the experiments to which this question refers, which makes it impossible for it to be answered. However, I will try to help you in the best possible way.

A dependent variable is one that is influenced by an element, in order to present a result, that is, it is a variable that does not establish itself, being dependent on another variable to establish itself. An example of a dependent variable can be seen in an experiment that seeks to determine the differences in growth rates of bean plants that were fertilized with different organic fertilizers. As you can see, this is an experiment where the different organic fertilizers influence differences in the growth rate of bean plants. Thus, the growth of these plants depends on the fertilizer, this growth being the variable dependent on the experiment.

A control group, in turn, is an element of the experiment that does not receive the element that is being tested in the same experiment. The control group is important, because it allows the researcher to see the results of a system where the tested element does not exist, thus being able to determine the real differences that the tested element is capable of causing. Using the same example presented in the paragraph above, we can see that the different organic fertilizers are the elements tested in the experiment. These fertilizers will be applied to the plants, however it is important that at least one of these plants does not receive any fertilizer, so that the difference between a system with fertilizer and a system without fertilizer can be evaluated. This plant that received no fertilizer is the control group.

4 0
2 years ago
How do the prefixes endo- and exo- help you remember the definitions of the terms endocrine and exocrine?
Tasya [4]

Answer: it shortened the name and easier to remember

Explanation:

8 0
3 years ago
Read 2 more answers
Describe the factors that influence the development and type of soil in a certain area.
arsen [322]

Soil research has shown that soil profiles are influenced by five separate, yet interacting, factors: parent material, climate, topography, organisms, and time. Soil scientists call these the factors of soil formation

4 0
3 years ago
Can anybody answer this
NARA [144]

Answer:

Options A, B, E, and F are correct

Explanation:

A). In the cell cycle, DNA replication is a process by which a duplicate DNA strand is produced with the help of replication machinery (enzymes, nucleotides, etc.). The overall process ensures that the newly developed strand is free of any mutations (errors) causing the production of wrong proteins at later stages. Although, there are chances of positive, negative or neutral mutations, the replication machinery aims to avoid any such errors at this stage.

B). DNA stores genetic information in the form of codes (known as codon) which needs to be translated in the form of proteins. This process is known as a transcription by which messenger RNA (mRNA) is produced in the nucleolus. Thereon, it is transported outside to encode proteins with the help of ribosomes. The process of copying genetic information on DNA in the form of mRNA is known is transcription.

E). The figure shown is also known as the central dogma of life. According to which, DNA (genetic information) is transcribed into RNA, which is then translated to proteins. In brief, RNA molecules brings the information from nucleous to ribosomes and make proteins. These proteins are often enzymes, hormones, and other biomolecules that perform the important functions in living organisms.

F). DNA and RNA are two types of nucleic acids responsible for all types of life on Earth. Since both of them are well recognized as nucleotides, they are made up of the same genetic building blocks known as nucleotides. Further, each nucleotide is comprised of a five-carbon sugar, a phosphate group, and a nitrogen base. The sequence of these nucleotides is responsible for the production of specific types of proteins.

3 0
3 years ago
How does aero and anaerobic respreastion differ
saveliy_v [14]
Aerobic respiration takes place in the mitochondria and requires oxygen and glucose, and produces carbon dioxide, water, and energy.

anaerobic respiration also produces energy and uses glucose but it produces less energy and does not require oxygen.
3 0
3 years ago
Other questions:
  • Which of the statements describes Neanderthals?
    6·1 answer
  • Bill has a perfect cube of an unknown substance. The density of the substance is 3.0 g/cm. He
    10·1 answer
  • Asexual reproduction requires how many parents?
    5·1 answer
  • To see a general view of a microscope slide, use _____ power. If you need to see a more specific and detailed view, use _____ po
    7·1 answer
  • Select all that apply.:Which structures are found in plant cells?. . A. central vacuole. . B. cell wall. . C. cilia. . D. chloro
    6·1 answer
  • Why is adaption necessary for species survival ?
    14·2 answers
  • Which of the following appears most likely to be true? Which of the following appears most likely to be true? As sediment increa
    15·1 answer
  • What causes different versions of the myostatin protein
    14·1 answer
  • 5. Which of the following explains a way in which metamorphic rocks are formed?
    14·1 answer
  • Which of these food molecules is used as an energy source in cellular respiration
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!