Because the molecules that are being transported is moving against its concentration. gradient. in other words, its moving from where it's low in concentration to where it's high in concentration.
Answer:
While plant cells have chloroplasts to photosynthesize, they also require ATP for cellular functions, and do use oxygen to break down some of the sugar they produce in order to generate that ATP. They need mitochondria for this.
In particular, at night when there is no light, plants undergo cellular respiration since there is no sunlight to photosynthesize.
They do, however, produce far more sugar and oxygen through photosynthesis than they use up in respiration.
Answer:Amphibians evolved during the middle of the Devonian period (416 to 359 million years ago) from the lobe-finned fish of the vertebrate class Sarcopterygii. Species within the genus Ichthyostega (members of the Labyrinthodontia subclass) are considered by some scientists to be the earliest amphibians.
Explanation:
wow thats tricky................ i think its asymmetrical or radial
