Why are dark green vegetables such as kale and spinach good sources of vitamin a? why are dark green vegetables such as kale and spinach good sources of vitamin a? they contain vitamin c precursors of retinol. they contain the most abundant preformed vitamin a. they contain abundant beta-carotene, a precursor of retinol. they are fortified with vitamin a?

Autotrophs a.consume their food to get energy b.may use photosynthesis to gain energy c.are also called consumers d.cannot use solar energy

Organisms are classified, or grouped into categories, based on similarities in their characteristics and/or evolutionary relationships. the study of how organisms are classified is known as

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.