Why is the immune response faster after vaccination than the
response that occurs the first time a pathogen invades?

Which of the following statements is most likely correct about a rock belonging to the jurassic age and a rock belonging to the cambrian age? options: 1) they have identical fossils of organisms that have evolved over time. 2) both have animal fossils preserved in them due to weathering and erosion. 3) they contain different fossils because life on earth has changed through time. 4) the fossils in them were formed on the surface of earth due to exposure to sunlight.

¿cómo demostraron los experimentos de griffith que un factor hereditario estaba involucrado en la transformación bacteriana?

What is a food chain? a.different animals located in different communities b. energy transferred from the sun to plants and then to a series of living things c. rows of crops, such as lettuce, in a field d.animals using one another as food for energy and growth