Answer:
vaccines use the killed version of the germ that causes a disease.
Explanation:
Inactivated vaccines usually don't provide immunity (protection) that's as strong as live vaccines. So you may need several doses over time (booster shots) in order to get ongoing immunity against diseases
Independent variable i think
The answer is; C
Most often some ancestral characters are preserved in an organism's development hence can be used to study evolutionary relationships. One of these features is the gill slits in embryos. These have been used to postulate that all land organisms, that exhibit gill slits in their embryonic development, emanated from a common fish ancestor. In humans, these gill slits later develop in the pharyngeal.
The spines of the cactus have several functions, which are the following:
To defend them from possible predators: inside the body of the plants there is a great deal of water; if herbivores could access it, these plants would not survive.
To provide them with shade: it is true that not much, but it is enough so that the loss of water by evaporation is minimal.
Reflect sunlight: many species have white spines.