Enzymes catalyze reactions by lowering the activation energy of the reaction. Enzymes are made of proteins, and therefore the answer here is B. Protein molecules.
Answer: Receives food that the duodenum have been digesting;
And then begins the absorption of major nutrients as well as Vitamin B12 and bile salts.
Explanation: The duodenum which is the first section of the small intestine is where most of the chemical digestion takes place as well as absorption of iron, enzymes are been secreted from the gall bladder, pancreas, liver et cetera into the duodenum to help breakdown the fat and protein as well as further break down the carbohydrates.
The food then goes through the jejunum and lleum where absorption of major nutrients as well as Vitamin B12 and bile salts into the blood stream begins.
<u>Answer:</u>
Free-living flatworms have developed a nervous system which helps them to sense the food. They have a head at one end of the body and each side of the head has sensory cells. These cells help them to sense chemicals and other movements around them.
While Parasitic flatworms don't have any nervous or digestive system as they live on the food digested by the host. They have special hooks attached to their head which help them to attach a host. They have developed some covering called 'teguments' which protect them from digestive liquids.
The Galapagos islands. the grants studied finches on these islands to learn more about evolution
