This topic contains a solution. Click here to go to the answer

Author Question: Today, there are over 270,000 plant species with conductive tissues and material flow systems known ... (Read 310 times)

kaid0807

  • Hero Member
  • *****
  • Posts: 515
Today, there are over 270,000 plant species with conductive tissues and material flow systems known as
 
  A) vascular plants. B) xeriphytes. C) blue-green algae. D) cyanobacteria.

Question 2

The gaseous oxygen in Earth's early atmosphere was a by-product of
 
  A) photosynthesis.
  B) photochemical reactions breaking down ozone (O3 ) to form oxygen (O2 ).
  C) volcanic outgassing.
  D) decay of organic matter.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

Jevvish

  • Sr. Member
  • ****
  • Posts: 326
Answer to Question 1

A

Answer to Question 2

A





 

Did you know?

People who have myopia, or nearsightedness, are not able to see objects at a distance but only up close. It occurs when the cornea is either curved too steeply, the eye is too long, or both. This condition is progressive and worsens with time. More than 100 million people in the United States are nearsighted, but only 20% of those are born with the condition. Diet, eye exercise, drug therapy, and corrective lenses can all help manage nearsightedness.

Did you know?

The heart is located in the center of the chest, with part of it tipped slightly so that it taps against the left side of the chest.

Did you know?

According to research, pregnant women tend to eat more if carrying a baby boy. Male fetuses may secrete a chemical that stimulates their mothers to step up her energy intake.

Did you know?

The average older adult in the United States takes five prescription drugs per day. Half of these drugs contain a sedative. Alcohol should therefore be avoided by most senior citizens because of the dangerous interactions between alcohol and sedatives.

Did you know?

Parkinson's disease is both chronic and progressive. This means that it persists over a long period of time and that its symptoms grow worse over time.

For a complete list of videos, visit our video library