Concept explainers
Videos
Almost all of the oxygen gas in today's atmosphere is present as a result of
a. outgassing from volcanoes.
b. aerobic respiration.
c. endosymbiosis.
d. photosynthesis.
Introduction:
The earth is the only planet, which supports life and this is because of the presence of life-supporting environment. Prokaryotes is said to be the first organism originated billion years ago and survived by using available resources like hydrogen sulfide from volcanoes and carbon dioxide in the atmosphere. Photosynthetic bacteria performed anaerobic respiration as there was no oxygen in the atmosphere.
Answer to Problem 1MC
Correct answer:
Almost the entire amount of oxygen gas present in today’s atmosphere is due to photosynthesis.
Explanation of Solution
Explanation for the correct answer:
Option (d) is given that photosynthesis is the source of almost all the oxygen present in today’s atmosphere. Photosynthetic bacteria used water (H2O) to carry out the photosynthesis process and as a result, oxygen is released abundantly into the atmosphere. Carbon dioxide and water are used to produce carbohydrates where oxygen is released as one of the end products. Hence, option (d) is correct.
Explanation for incorrect answers:
Option (a) is given that outgassing from volcanoes is the source of oxygen content present in today’s atmosphere. As volcanoes erupt, outgassing provided the hydrogen required for photosynthesis process. But oxygen is not the end product when hydrogen sulfide from volcanoes is used. So, it is an incorrect option.
Option (b) is given that aerobic respiration is a process which breaks down complex substances in the presence of oxygen to result in simple substances in order to obtain energy. It is the process which uses oxygen and it does not release oxygen. So, it is an incorrect option.
Option (c) is given that endosymbiosis occurs when two organisms live in a harmonious relationship where one organism lives inside another organism. So, it is an incorrect option.
Hence, options, (a), (b), and (c) are incorrect.
Thus, it can be concluded that the abundant oxygen content in today’s atmosphere is due to the ability of organisms, which use water for photosynthesis and release oxygen as one of the products.
Want to see more full solutions like this?
Chapter 18 Solutions
Biology: Life on Earth (11th Edition)
- The first organisms that oxygenated the atmosphere were a. cyanobacteria b. phototrophic organisms c. anaerobic organisms d. all of the abovearrow_forwardIt has recently been discovered that blue-green algae (photosynthetic bacteria) can adjust the wavelength of light they use. It is most likely that they adjust the: A. Photosynthetic pigments B. Chloroplast number C. Photosynthetic mechanism D. Timing of photosynthesisarrow_forwardHuman use of fossil fuels has what consequences? Group of answer choices a. increase in CO2 concentration in the atmosphere b. return of fossilized carbon to the active carbon cycle c. increase in global temperatures d. all of the other optionsarrow_forward
- A rise in oxygen in Earths air and seas set the stage for the evolution of _______. a. aerobic respiration c. photosynthesis b. fermentation d. sexual reproductionarrow_forwardIn 1941, biologists exposed photosynthesizing cells to water containing a heavy oxygen isotope, designated 180. The "labelled" isotope appears in the 02 gas released in photosynthesis, showing that the oxygen came from water. Where would the 180 have ended up if the researcher had used 180-labeled CO2 instead of H2O? A. ADP B. NADP+ C. Rubisco D. DP and NADP+ E. Glucosearrow_forwardWhy are many people especially concerned about the release of carbon dioxide through fossil fuel combustion? A. Carbon dioxide is by far the most abundant of the greenhouse gases released through human activities. B. More than any other climate driver, carbon dioxide has contributed the most to the global rise in temperature since the industrial revolution. C. Carbon dioxide turns over very slowly, so the carbon dioxide released into the atmosphere today can affect the global climate for thousands of years into the future. D. All of the above are correct E. None of the above are correctarrow_forward
- O2 released in the process of photosynthesis comes from: A. CO2 B. water C. sugar D. pyruvic acidarrow_forwardOver the past decades, the CO2 concentration in the atmosphere has increased. a. Predict the effect of increasing carbon dioxide concentrations on photorespiration. b. Scientists suggest that increasing CO2 concentrations are leading to higher average global temperatures. If temperatures are increasing, does this change your answer to part (a)?arrow_forwardWhich type of organism does NOT photosynthesize? a. Heterotrophs b. Producers c. Cyanobacteria d. Algae e. Autotrophsarrow_forward
- Why do you suppose plants and forests appeared in large numbers before large animals did? Several of the choices may be correct. Select the options you expect to be the strongest contributing factors.A. Animals need food, and there was none on land before plants. B. Plants were driven to land by scarce resources in the oceans, such as light and minerals. C. It was too cold for animals at first. D. Animals are more susceptible to radiation and needed more ozone in order to survive out of the water. E. The order was pure chance and could have gone either way. F. There was not enough oxygen for lungs to be effective before plants colonized land. G. The increased oxygen levels produced by land plants accelerated animal evolution. H. Plants had to change less to survive on land.arrow_forwardThe conversion of light energy to chemical energy stored in food molecules is known as Select one: a. Reproduction b. Degradation c. Respiration d. Photosynthesisarrow_forwardWhich of the following is NOT a question suitable for scientific inquiry? Select an answer a Which fossil fuel is the dirtiest to burn? b Is it ethical to put heavily polluting industries in low-income neighborhoods? c Does the burning of fossil fuels contribute to global warming? d Does the use of renewable energy sources contribute to ozone depletion?arrow_forward
Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College