« previous next »

Author Question: The habitable zone is the area around a star where: A) planets with life have been found. B) ... (Read 79 times)

luvbio

  • Hero Member
  • *****
  • Posts: 623
on: Jul 27, 2018
The habitable zone is the area around a star where:
 
  A) planets with life have been found.
  B) human beings could live.
  C) the Greenhouse Effect is possible.
  D) a planet could have an atmosphere.
  E) temperatures are suitable for planets to have liquid water.

Question 2

Why does detection of abundant free oxygen in an atmosphere suggest life is present? Does its absence prove life could not be present?
 
  What will be an ideal response?


lkanara2

  • Sr. Member
  • ****
  • Posts: 329
Reply #1 on: Jul 27, 2018
Answer to Question 1

E

Answer to Question 2

Oxygen is highly reactive, and unless quickly replaced by photosynthesis, would soon disappear into surface rocks, as it has on Mars and Venus. However, life on Earth certainly evolved before it released the abundant present oxygen, and on other worlds, photosynthesis may not have evolved. Yet other forms of life may thrive using methane or hydrogen sulfide, all energy processes found here as well.


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question

luvbio

  • Hero Member
  • *****
  • Posts: 623
Reply #2 on: Jul 27, 2018
TY


lkanara2

  • Sr. Member
  • ****
  • Posts: 329
Reply #3 on: Jul 27, 2018
You're welcome


« previous next »
 

Did you know?

In 2010, opiate painkllers, such as morphine, OxyContin®, and Vicodin®, were tied to almost 60% of drug overdose deaths.

Did you know?

Of the estimated 2 million heroin users in the United States, 600,000–800,000 are considered hardcore addicts. Heroin addiction is considered to be one of the hardest addictions to recover from.

Did you know?

The tallest man ever known was Robert Wadlow, an American, who reached the height of 8 feet 11 inches. He died at age 26 years from an infection caused by the immense weight of his body (491 pounds) and the stress on his leg bones and muscles.

Did you know?

After 5 years of being diagnosed with rheumatoid arthritis, one every three patients will no longer be able to work.

Did you know?

Autoimmune diseases occur when the immune system destroys its own healthy tissues. When this occurs, white blood cells cannot distinguish between pathogens and normal cells.

The Many Faces of Life (Part 2) The Many Faces of Life (Part 2)
Clinical Embryology Training:Promising career for Life science Graduates Clinical Embryology Training:Promising career for Life science Graduates
How to find the area of a function using limits and Riemann sums How to find the area of a function using limits and Riemann sums
The European Alps have lost ~30% to 40% of surface area and ~50% of volume since the 1850s. The European Alps have lost ~30% to 40% of surface area and ~50% of volume since the 1850s.
The surface temperature of the star is 6000 K. At what wavelength is its light output a maximum The surface temperature of the star is 6000 K. At what wavelength is its light output a maximum
Life support system of a developing human Life support system of a developing human
Video: Automated external defibrillator (AED)

For a complete list of videos, visit our video library