Circulatory system.....circulates blood (a vital delivery system of oxygen) throughout the whole body when tissues need it the most and with a constant supply.
Answer:
Structure and function of the cell membrane
The cell membrane is semipermeable (or selectively permeable). ... The unique structure of the cell membrane allows small substances (like oxygen or carbon dioxide) to easily pass through.
Explanation:
<span>B. Inherited behaviors that allow animals to survive and reproduce will be spread throughout the population and can evolve by natural selection.</span>
Answer:
smaller and less smooth i think
protein digestion begins when you first start chewing. there are two enzymes in your salvia called amylase and lipase. they most break down carbohydrates and fats. Once a protein source reaches your stomach, hydrochloric acid enzymes called proteases break it down into smaller chains of amino acids
