Scientists have yet to prove that the current global warming trend is not part of the natural cycle of Earth. Many things are being done now, mostly focusing on emission controls placed upon industry and transportation.
By starch, I'm assuming you mean glycogen, or animal starch.
Similarities:
Both are polysaccharide molecules made from glucose molecules linked together in a long chain.
Both are storehouses of energy.
Differences:
Glycogen is made in animal cells and is the only form of starch animals can digest (unless they have certain microbes in their intestinal tracts to break down cellulose, which all herbivores need).
Cellulose is made in plant cells.
The bonds are a bit different; the molecules are isomers. Glycogen bonds with what is called an alpha 1,4 bond, meaning that the first carbon of one glucose molecule is bonded to the 4th carbon of the next glucose molecule, but in a way that puts the bonds in a shape that falls below the plane of the molecule, and allows branching.
Cellulose bonds with beta 1,4 bonds. The first and fourth carbons of adjoining glucose molecules are still connected, but the shape of the bond falls above the plane of the molecule and does not branch.
Since enzymes are specific to their substrates, the enzymes shaped to fit glycogen bonds do not fit on cellulose bonds, which is why animals cannot digest cellulose on their own. In herbivores, there are microbes in their digestive tracts which can produce enzymes to break these bonds so the glucose can be used. In carnivores and omnivores like humans, there is no enzyme to break down cellulose so it becomes 'roughage' in our diets. It passes through the digestive tract without being broken down.
Answer:
Sugars
Explanation:
Phloem is a living tissue inside the plants, where it can flow in either direction. Inside the phloem, it will have a cell, which both ends have walls with perforations. So the sugars will travel through them in both directions.
Answer:
Xylem and phloem
Explanation:
Xylem and phloem are the conducting tissues of the vascular strands. Their main role is in the transportation of food, minerals, and water. Xylem is the tissue which is responsible for the transport of water in plants while the phloem is responsible for the transfer of food and nutrients in the plant.
