Answer: Ecosystem
Explanation: An ecosystem consists of all the biotic and abiotic factors in an area and their interactions. A niche refers to the role of a species in its ecosystem. A habitat is the physical environment in which a species lives and to which it is adapted.
Heat must be added to make a reduction reaction.
Adaption, evolution, variation are all causes of natural selection.
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brainliest..?
The statement that is true is active transport moves against the concentration gradient.
<h3>WHAT IS ACTIVE TRANSPORT</h3>
Active transport is one of the two types of cellular transport that involves the movement of molecules against a concentration gradient.
This moves that movement occurs from a region of lower concentration to a region of higher concentration. Since movement is against a concentration gradient, it involves input of energy (ATP).
Therefore, the statement that is true is active transport moves against the concentration gradient.
Learn more about active transport at: brainly.com/question/2503897
The mouth is the beginning of the digestive tract. In fact, digestion starts here as soon as you take the first bite of a meal. Chewing breaks the food into pieces that are more easily digested, while saliva mixes with food to begin the process of breaking it down into a form your body can absorb and use. Hope I’ve helped ;)