Which of the following were or soon became a challenge for survival of the first land plants? 1) sources of water 2) sperm transfer 3) desiccation 4) animal predation 5) competition with other plants for light

Explain the difference between incomplete dominance and codominance

What is the difference between the conducting zone and the respiratory zone of the respiratory system? the conducting zone is a series of cavities and tubes that move air to the respiratory zone where gases exchange with the bloodstream. the conducting zone exchanges gases between the lungs and the alveoli and the respiratory zone is a series of cavities and tubes that move air to the conducting zone. the conducting zone moves oxygen into the cells and the respiratory zone takes carbon dioxide away from the cells. the conducting zone moves oxygen into the bloodstream and the respiratory zone takes carbon dioxide away from the bloodstream.

About __ of the mass of the cell is water