How did the time it took the body to respond to the pathogen change after the second exposure?

When a foreign antigen or pathogen enters our body, our immune cells detect it and generate a response by producing antibodies against it. Also, our immune cells generate memory cells so that our body remembers this pathogen if it invades the body afterwards. Hence, it takes less time for an organism's body to generate a response when a pathogen invades for the second time. The memory cells immediately detect the pathogen and a response is generated.

carbohydrates: (starches and sugars) composed of carbon, hydrogen, and oxygen.

lipids: (fats, oils, and waxes) are made of carbon and hydrogen atoms.

nucleic acids: contain hydrogen, oxygen, nitrogen, carbon, and phosphorus. they are polymers of nucleotides. a nucleotide has three parts, a 5-carbon sugar, a phosphate     (-po⬇️4) group, and a nitrogenous base.

proteins: made up of nitrogen, carbon, hydrogen, and oxygen. they are polymers of amino acids.

genetic variation will increase because of a new habitat and food source.

explanation: