« previous next »

Author Question: The habitable zone is the area around a star where: A) planets with life have been found. B) ... (Read 23 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?

It is believed that humans initially contracted crabs from gorillas about 3 million years ago from either sleeping in gorilla nests or eating the apes.

Did you know?

Many medications that are used to treat infertility are injected subcutaneously. This is easy to do using the anterior abdomen as the site of injection but avoiding the area directly around the belly button.

Did you know?

Essential fatty acids have been shown to be effective against ulcers, asthma, dental cavities, and skin disorders such as acne.

Did you know?

Serum cholesterol testing in adults is recommended every 1 to 5 years. People with diabetes and a family history of high cholesterol should be tested even more frequently.

Did you know?

Medication errors are three times higher among children and infants than with adults.

A consensus tree of life A consensus tree of life
Planets and Their Stars Planets and Their Stars
Major Findings of the High Scope Preschool Study High Scope participants showed better academic per Major Findings of the High Scope Preschool Study High Scope participants showed better academic per
Urban Life Urban Life
Neck and Occipital Ridge. Apply thumb compression across the area at the base of the big toe. One ... Neck and Occipital Ridge. Apply thumb compression across the area at the base of the big toe. One ...
Life cycle of Pisum sativum Life cycle of Pisum sativum
Video: Arthritis

For a complete list of videos, visit our video library