The double membrane. It's theorized that chloroplasts used to be their own single-celled organism in the environment (and therefore with its own membrane). Then, the theory states, a larger cell took in the chloroplast by endocytosis, which involves surrounding the chloroplast in the large cell's own membrane. The chloroplast would then have two membranes surrounding it. This is similar to the thinking for mitochondria becoming an organelle as well. Hope this helps! :)
<span>The first carbon dioxide is produced in between glycolysis and the Krebs/citric acid cycle. </span>
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
Answer:
D. contact metamorphism
Explanation:
When there's a volcanic activity in certain area, very often it happens that there's magma that intrudes into the cold rock in the surrounding area. The intrusion of the hot magma into the cold rock layers causes big changes into the structure of the rocks. The high temperature and high pressure manage to influence the structure of the preexisting rocks, mostly on the places where the magma touches the cold rocks, leading to the formation of metamorphic rocks. This type of metamorphism is known as contact metamorphism.
